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Why use probiotics for your cat?
Medical studies show that most of your cat’s immune system develops and functions in the intestines. It is therefore important to keep your feline’s intestinal flora strong, as this will affect the rest of his health. A simple way of keeping your pet’s flora strong is through the use of probiotics. Probiotics are healthy bacteria that help strengthen your pet’s immune system. Probiotics are not just a short-term treatment, they are a long-term supplement that will protect your cat from infections and conditions such a flatulence, diarrhea, or toxin buildups. Adding probiotics to your cat’s diet will significantly reduce the stench of your pet’s cat litter, will protect him from harmful bacteria and will increase your pet’s lifespan.
Your feline’s flora can be affected by many different factors, like diet, stress or medical treatments. This is an especially big issue for domesticated animals, who usually find their healthful bacteria in the wild, and are often fed food that does not meet all their nutritional needs. An unhealthy flora is nearly impossible to detect, yet it weakens your animal’s entire health. This is why adding probiotics to your animal’s diet in the form of supplements is especially important.
NOVAnimal probiotics for a healthier cat
Probiotic supplements for humans are not appropriate for animals. This is the reason why all of NOVAnimal products were developed by microbiologists and veterinarians with the specific needs of your animal in mind. NOVAnimal probiotics come in powder form which has a natural plum flavor, making them delicious as well as healthy for your cat. Our veterinary line contains three different products tailored to fit your pet’s needs, as they contain between 3 and 7 billion probiotics per scoop.
Many studies show that probiotics strengthen your cat’s immune system and keep its bacteria levels balanced and stable. The Effect of Probiotics on Animal Health paper supports this information stating that “Unfortunately the ability of natural flora to fight intestinal infections is not always effective. Supplementation of intestinal microflora with probiotic bacteria was proven to support and help treating infections”. Studies show that probiotics have a long-term effect on your cat’s health, and will improve his lifestyle.
Contact us today with any questions you may have or to find out which NOVAnimal product is right for your cat. | <urn:uuid:da48de86-5950-460c-aa69-10812aa12583> | CC-MAIN-2022-33 | https://novaprobiotics.com/probiotics-for-cats/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.948461 | 511 | 2.109375 | 2 |
1. f. Ability of a living thing to adapt to a disturbing agent or an adverse state or situation. 2. f. Ability of a material, mechanism or system to regain its initial state when the disturbance to which it had been subjected has ceased.
Put to (re) think or (re) build paths for criticism, we can not fail to take into account the profusion of curatorial statements , presentations, articles in scientific journals, doctoral theses, songs, corporate coaching programs, cosmetic brands or even posts with slogans of pseudo-therapeutic ancestry and beautiful backgrounds that define resilience as an a priori vindictive, admirable attitude, one would say even heroic, in a world full of inequality, competitiveness and dominated by the law of stronger. Of course, the vital capacity to deal with trauma deserves our full consideration, but that should not prevent the inflation of a concept from carrying any suspicion.
To begin with, we might ask who is really in a position to overcome a trauma. Literary critic Daniele Giglioli describes Senza trauma. Scrittura dell'estremo e narrativa del nuovo millennio (Quodlibet, 2012) a society that escapes all apprehension of pain, that accommodates without regard to its comfort zone, which has the privilege of "trauma without trauma", a kind of desire for trauma or imaginary trauma as a factor of identity, of law, of moral superiority. It is worth noting that resilience has, however, been a particularly debated idea in the American context, and in particular in Latin America, where our comrades are exposed to scales of violence and traumatic processes that are difficult to imagine from a comfortable Europe.
But one would even have to wonder if resilience would not, in fact, be participating in the dominant culture - that of do it yourself - as an analgesic or in the form of an ethic of sacrifice. Here the two meanings of the SAR are tremendously revealing: on the one hand, this appeal to "adaptation" and, on the other hand, this ability to "recover an initial state." We would say that such definitions outline the ideal scenario for certain powers to discharge their responsibility in the individuals to whom they subject, while ensuring a certain conservative logic, rather than aspiring to improve, transform or directly overcome this initial state, for example. if unfair and deficient. And despite that, as Daniel Gasol wonderfully develops in his recent Art (in) useful. On how capitalism deactivates culture (Green Ray, 2021), contemporary art often functions as a useful narrative for capitalism, it should be remembered that perhaps this is precisely where all this can also go into crisis: this place where the impossible you can still imagine. | <urn:uuid:dbfe13bf-29e9-4fbe-9341-d78b315694b9> | CC-MAIN-2022-33 | https://bonart.cat/en/n/43165/resilience | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.944122 | 552 | 2.75 | 3 |
Chemicals can be toxic, by which we usually mean that they are, to a greater or lesser extent, toxic to humans. This toxicity can have consequences, both in the short and the long term. In the first case we speak of acute toxicity and in the second case of chronic toxicity. In the latter case we think of e.g. carcinogenic, mutagenic or reprotoxic (CMR) effects.
Is a toxicity rating available?
Two simple rough-and-ready rules to get a first impression of the toxicity of chemicals are : watching their classification on the label or in the SDS (SDS), or looking at already established limits.
On the basis of the classification
Through a critical look at the classification of the hazardous product according to DSD / DPD (Dangerous Substances directive / dangerous preparations directive) or CLP / GHS(classification, labeling and packaging / globally harmonized system), you can quickly assess the dangers. Where severe acute or chronic effects are possible, the risk is the greatest. Early 2012, The FPS ELSD published a poster (Dutch and French) in which the old and new system are compared to each other and one gets an overview of all hazardousproperties, based on the classification. If an MSDS is not available, you may have to check the websites of the suppliers, or paying databases. A free alternative are the International Chemical Safety Cards (ICSC) where a lot of basic information, also about the toxicity, is summarized, per substance.
On the basis of limit values
In the table below, there are two commonly used, simple interpretations of the toxic characteristics of a product, on the basis of defined limit values:
|Toxicity class||Method 1||Method 2|
|as gas/vapor (in mg/m³)||as aerosol (in mg/m³)||as gas/vapor (in ppm)|
|very high toxicity||<10||<0,1||<0,1|
There is no toxicity assessment available?
Do not worry, there are many (free) databases in which you can search for the toxic properties of substances and products. You can make your own assessment in for instance threesteps:
Step 1: Collect toxicity information: Patchwork (Dutch) is here a great tool. In this PDF flowchart there are hyperlinks to all major free Internet databases
Step 2: on the basis of this, establish a critical effect (for example, on the basis of the lowest DNEL, NOAEL, ... for a specific effect)
Step 3: on the basis of this, determine the toxicity class, such as:
- class 0: little toxic, effect only occurs on excessive exposure
- class 1: slightly toxic, effect is reversible, but some nuisance
- class 2: moderately toxic, effect occurs but the damage is not permanent
- class 3: very toxic, effect occurs and damage is permanent
- class U: unknown, no data on occurrence of the effect
- AEGLs concentration guidelines of the American EPA for a single exposure to acute toxic substances with high priority (emergency planning)
- ERPGs concentration guidelines of the American AIHA for a single exposure within the framework of accident prevention and emergency planning
- EPA IRIS assessments
- IARC Monographs
- Intervention values Dangerous Substances 2007 (Dutch) Dutch set of health-based limit values to determine the risk level for social workers
- BMDS Benchmark Dose Software
- Demeter (French) INRS database reprotoxic compounds
- ECHA C&L click "CL Inventory" to find the classification of a substance
- GESTIS Substance Database
- MIXIE Canadian platform to assess toxicological effects of combinations of dangerous substances (some 700), on the basis of literature data
- Patchwork (Dutch) helps you to choose the right databases to get an answer to your question
- https://web.archive.org/web/20131106181548/http://esis.jrc.ec.europa.eu/ ESIS stands for the European chemical Substances Information system
- http://toxnet.nlm.nih.gov/ American compilation of databases regarding toxicological and other properties of hazardous substances
- http://www.bcfi.be/ (Dutch) or http://www.cbip.be/ (French) Belgian Centre for Pharmacotherapeutic Information (information on active substances in drugs)
- http://www.hse.gov.uk/ the British Health and Safety Executive has a theme page on the toxicity levels of chemicals as well as the risks of dermal exposure
- http://www.epa.gov/iris IRIS stands for EPA's Integrated Risk Information System, risk assessment for human health resulting from environmental exposure to chemicalcontaminants
- http://www.inchem.org/ Canadian site about the management of hazardous substances
- http://www.osha.gov/ has a specific section on dermal exposure
- http://www.toxpro.be/toxprofr/toxprohpfr.htm (Dutch and French) shared site of three universities (UCL, ULg & VUB) on chemical risks
- http://www.employment.belgium.be/home.aspx has a specific page on chemical agents (Dutch and French) | <urn:uuid:29314b4b-e317-47fb-956d-643eee42a4ec> | CC-MAIN-2022-33 | https://www.bsoh.be/?q=en/node/75 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.84242 | 1,188 | 3.453125 | 3 |
The Portuguese Water Dog was a loyal companion who accompanied the fisherman aboard his boat. The dog was required to spend long hours working in a variety of ways such as helping with fishing lines or, before the advent of radio, the dog would courier messages from boat to boat or boat to shore. When visiting foreign ports, the Portuguese Water Dog was left to guard the boat and its catch.
In the 1970s, when our breed was quite rare, many Portuguese Water Dogs were used for breeding. Today more than 10,000 Portuguese Water Dogs are registered around the world, so there is no longer a need to breed any other than the healthiest, most correct dogs. As the standard says, "This highly intelligent utilitarian breed is distinguished by two coat types, either curly or wavy; an impressive head of considerable breadth and well proportioned mass; a ruggedly built, well-knit body; and a powerful, thickly based tail, carried gallantly or used purposefully as a rudder. The Portuguese Water Dog provides an indelible impression of strength, spirit and soundness."
Portuguese Water Dogs are very versatile. In addition to being much adored family members, they excel in Therapy Work, Agility, Tracking, Obedience, Rally, and Flyball. Some have done Lure Coursing, Herding and Dock Diving. They are at their happiest when they have a job to do. PWDs have a great sense of humor and will use it quite often. If left to their own devices, they may come up with entertaining games that would be frowned upon in your establishment! We have a saying - "Out of sight equals in trouble" and it definitely pertains to this breed! | <urn:uuid:69b9e522-32ca-448f-92de-48851f3c39bd> | CC-MAIN-2022-33 | https://www.delmarvapwd.org/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.975676 | 346 | 2.34375 | 2 |
Ukulima Tech believes that a healthy, organic, and sustainable lifestyle can be achieved through their Vertical Gardens. The Vertical Garden provides consumers with the ability to grow their vegetables and herbs with minimal inputs of water, labor, and land space.
In Nairobi, more than 4 million people are affected by food insecurity challenges. Ukulima Tech's mission is to combat food scarcity in Kenya, in Nairobi in particular. Ukulima Tech believes that vertical gardens can ensure that urban households can live a sustainable, organic, and healthy lifestyle by producing their herbs and vegetables.
Ukulima Tech aims to promote a sustainable, healthy, and organic lifestyle through its innovation - the vertical gardens.The vertical garden is an innovation that seeks to promote urban farming in a country where there’s a scarcity of land in the city center. The vertical gardens can be seen as a new revolutionized method for food production for urban households. The innovation itself entails that consumers can plant herbs and vegetables of their choosing in their backyard, verandah, and balconies.
The Vertical gardens are very easy to use and are low maintenance, which makes it easy for every household to grow their vegetables and herbs with little to no experience. Thus, this innovation has revolutionized food production in Kenya and can ensure that its consumers can live a healthy, sustainable, and organic lifestyle while consuming nutritious food.
The next step
CFIA students from the minor FI4SGD helped Ukulima Tech with their next step, which was how to frugalize their innovation for low-income households. The project included making a business model for the enterprise where the main focus is to make a marketing strategy but also a business plan for the upcoming years. Moreover, in terms of frugalization, the design of the vertical gardens was adjusted to ensure a more sustainable innovation. Lastly, CFIA students studied the social impact of the innovation to analyze the impact on gender, environment, but also on sustainability.
Sustainable Global Development
The research project initiated by Ukulima Tech aims to investigate how their Vertical Gardens can advance towards the UN Sustainable Development Goal 2 (zero hunger)
One of the main sustainable development goals that Ukulima Tech is working on is to achieve “Zero Hunger”. Ukulima Tech’s mission is to ensure that its consumers can live a healthy, organic, and sustainable lifestyle and consume herbs and vegetables that are nutritious and organic. Therefore, Ukulima Tech is working hard on combating food scarcity, which is a prevalent issue that affects the majority of Kenya. Thus, if households adopt this innovation, it can ensure a more healthy, sustainable, and organic lifestyle.
Elizabeth Achieng, Ukulima Tech Kenya
Sheila Suluve, Ukulima Tech Kenya
What Design Can Do - WDCD
Dr. André Leliveld (Leiden University)
Student Research Team
Dylan Clementia (Leiden University – International Relations)
Rebecca Baugh (TU Delft – Architecture)
Alesha Wong (Erasmus University – Economics and Business economics) | <urn:uuid:d161bd37-07dc-454c-a6b0-e35ed583ebd6> | CC-MAIN-2022-33 | https://www.icfi.nl/projects/ukulima-tech | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.926356 | 661 | 2.5625 | 3 |
Project: Wadi Rum Resort
Designed by Oppenheim
Location: Wadi Rum, Jordan
Oppenheim is no stranger to developing projects on a challenging location, perhaps the real challenge here was to blur the line between nature and man-made and design an outstanding 80,000 sqf hotel in Wadi Rum. The project is set to become reality by the year 2014.
Here, where desert sand meets desert stone, we see a singular opportunity to devise a new contract between man and nature. Reinterpeting the way we have dealt with the earth, our proposal establishes a new benchmark for design, quality and sustainability in the natural environment. To live in harmony with the natural world, we must learn how to re-engage the land. Earnest and timeless, the architecture is simlutaneously powerful, yet comfortable, primitive, yet innovative, casual, yet elegant, raw, yet refined. The built from merges silently with its wondrous setting, exploiting and enhancing the natural beauty of the site to establish luxury lodge accommodations – that are uniquely beautiful and luxurious. The resulting ancient connection with the universe through simple, elemental forms, sincere materiality, and the use of bountiful natural resources both physical and ethereal. Nature accelerated, enhanced and embrace, nature nurtured.
The architecture we will humbly create within the realm of the Wadi is intended to miraculously and meticulously add another sound in a perfect symphony, another ingredient in a perfect dish. The conceptual point of departure has its roots in the tectonic and geological histories of the region. Through an engagement of the existing natural faults and fissures, the architecture is inserted in the landscape with nominal impact and primal elegance – synchronizing with the topography. Symbiotically and sensitively attuned to the rhythms of the area – a responsible stewardship of the environment. The boundaries between man made and nature, interior and exterior are deliberately blurred establishing maximum effect with minimum effect. The lodges are nestled across the landscape, enhancing rather than distorting an awareness of the context. An enlightened new approach to living with the land and not simply upon it. Simplicity and functionality are inherent to the entire design, so that nothing distracts the eye. The lodges and villas in their various incarnations. | <urn:uuid:e4442f30-4156-4d94-b349-970d770cb660> | CC-MAIN-2022-33 | https://www.archiscene.net/firms/oppenheim/wadi-rum-resort-oppenheim/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.925544 | 474 | 1.601563 | 2 |
“but we must remember that good laws, if they are obeyed, do not constitute good government. Hence there are two parts of good government: one is the actual obedience of citizens to the laws, the other part is the goodness of the laws which they obey…”(Aristotle Politics 1294a-6). Therefore, what really are the reasons to have a code of ethics? Research reveals: 1. To help define what acceptable behaviors. 2. To promote high standards of practice. 3. To provide a benchmark for employees to use for self evaluation. 4. To establish a framework for professional behavior and responsibilities. 5. As a vehicle for company identity. Given these insights, certain questions need to be addressed. 1. Who decides what’s acceptable, the high standards, a benchmark, or a framework? If all if these “come down from on high” can “buy-in” be expected? 2. There must be a venue for all employees to have the opportunity for input for #1. 3. Where does the responsibility lie in promoting, reinforcing and enforcing the code of ethics? Compliance, HR, C-suite and what has been their training in the process of thinking ethically? 4. Is company identity that same as company reputation? If not, what’s the difference? Obviously, much thought and preparation need to go into the development of a code of ethics. So please go slow, think critically and implement carefully. | <urn:uuid:5a888382-43d9-42e4-b77d-e292a5f01df4> | CC-MAIN-2022-33 | https://www.frankbucaro.com/a-code-of-ethics-will-not-solve-all-your-ethics-problems/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.932833 | 307 | 2.609375 | 3 |
Piedmont Community College (PCC) will offer the Computer Literacy for Gaining Employment course on April 11 – May 11 on Tuesdays and Thursdays from 9 a.m. – 12 p.m. Classes are held at PCC’s Workforce Training Center located at 303 S. Morgan Street in Roxboro.
Students will learn basic computer concepts and skills in order to use computer technology in everyday life and to develop new employment opportunities. This course will help students develop a fundamental understanding of computers and develop the essential skills they will need to begin computing with confidence.
Participants will also learn Microsoft Word®, PowerPoint®, and Excel® basics. Successful students will earn an official Microsoft® Digital Literacy certification to add to their resumes and share with potential employers at job interviews.
To enroll in the Computer Literacy training or for more information, contact PCC’s Workforce Development Team at (336) 322-2156 or the Workforce Training Center at (336) 599-4620. The registration fee is waived for qualified unemployed, underemployed, and economically distressed individuals. | <urn:uuid:371f8a20-4951-456a-baa8-4e93b5e65c65> | CC-MAIN-2022-33 | https://www.piedmontcc.edu/news-article-8956-pcc-to-offer-computer-literacy-training/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.91601 | 229 | 2.0625 | 2 |
We offer courses from introductory to advanced levels that incorporate reading, writing, listening and speaking with exposure to diverse cultures. Courses are designed to enable students to acquire a functional competence of French, Italian, Latin and Spanish. Since the acquisition of a foreign language is closely linked with the culture of a given country, the instructors offer opportunities for students to appreciate, experience and learn to respect cultural differences through classroom discussions and/or presentation of a variety of materials.
"If you talk to a man in a language he understands, that goes to his head. If you talk to him in his own language that goes to his heart." - Nelson Mandela
Requirements: Students are required to complete 6 credits, in sequence, in any one foreign language offered in the Alvernia curriculum. Placement of the student in the appropriate course level is determined by testing and/or the decision of the foreign language department staff.
Placement Guidelines for Spanish Courses
Students should complete the following course sequence based on their prior years of foreign language study in high school:
Years of instruction: Course Sequence:
0-2 years of high school Spanish → Spanish 101 & Spanish 102
3-4 years of high school Spanish → Spanish 102 & Spanish 201
Note: Students will not receive credit for any course taken below their placement level. Exceptions to these guidelines must be approved by a foreign language faculty member
Placement guidelines do not apply for Spanish courses related to a profession.
Spanish for Native or Heritage Speakers
Students who are native or heritage speakers of Spanish will be placed in a Heritage speaker course or another course above the SPA 101 level as approved by a language faculty member.
- A Heritage speaker is defined as someone who has been exposed to a language other than English at home. Heritage speakers may not be bilingual, but they may have some proficiency and/or a cultural connection to the language spoken at home.
- A Native speaker is someone who was raised in an environment using a language other than English both in and outside of the home.
For more information regarding the Spanish for Heritage/Native Speaker courses, please contact Dr. Angelica Montoya (firstname.lastname@example.org).
- The Spanish minor consists of 6 courses (18 credits) from the following:
- SPA 102 or SPA 108 or SPA 190 (Spanish for Beginners II / Spanish for Health Professions II/ Spanish for Native/Heritage Speakers II)
- SPA 201 (Intermediate Spanish I)
- SPA 202 (Intermediate Spanish II)
- SPA 203 (Spanish Conversation and Composition I)
- SPA 204 (Spanish Conversation and Composition II)
- SPA 311 (Cultural Perspectives of Spain)
- SPA 312 (Cultural Perspectives of Latin America)
Transfer Credits/Credits by examination
- Students may transfer approved course credits from other colleges and universities. Refer to the following link for information on Transferring credits: https://www.alvernia.edu/current-students/registrar/registrar-transfer-credit
- Language testing for credits: Students may earn credits by completing and passing a CLEP (College Level Equivalency Program) examination in a foreign language. The CLEP exam is available for French, Spanish and German. Information regarding the CLEP examinations is available through the Registrar’s office and at https://clep.collegeboard.org/.
- Students who have previous study or knowledge of a foreign language other than French, Spanish or German may complete ACTFL (American Council for the Teaching of Foreign Language) exams through Language Testing International for credit. Please contact Antonella Merolla (email@example.com) for more information regarding these exams.
Living and studying outside of the United States can change you in ways you can’t begin to envision. Students who study abroad typically gain immeasurable confidence and experiences they could not have imagined. Alvernia’s Study Abroad Office works closely with students who want to spend one or more semesters in a different country. Opportunities to study abroad exist in Italy, Spain, Ireland, Mexico, New Zealand, England, Germany, Greece, Belgium, Austria, Morocco and Palestine.
Your college years are the perfect time to broaden your horizons and participate in experiences that will change your life. You pay the regular Alvernia tuition while studying abroad, and continue to receive financial aid, if applicable. Credits earned count toward your Alvernia undergraduate degree.
If you’re interested in studying in another country you should start planning early, as you’ll need to start the application process about a year in advance.
You can get more information about these programs from the Study Abroad Office by contacting firstname.lastname@example.org.
Francis Hall 228 | <urn:uuid:584d844b-5af3-4342-8681-e2da31721b5e> | CC-MAIN-2022-33 | https://www.alvernia.edu/academics/undergraduate-programs/majors-minors/world-languages | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.92784 | 1,039 | 2.171875 | 2 |
Image Pexels CC0 License
Do you wake up every morning wanting to hit the snooze button and feeling exhausted before the day has even begun? Maybe you find your energy levels are flagging around mid-morning, and by early afternoon, you are ready to take a nap. If this scenario sounds familiar to you, you likely regularly feel lethargic and lack the energy to live life to the full. Feeling like your energy levels are low and you are constantly tired can make it hard to get maximum enjoyment from every day of your life. You may also find this lack of energy impacts your motivation to exercise or participate in social activities, like meeting friends for dinner in the evening. Reclaiming your power and feeling refreshed is a fantastic feeling and one that you can achieve with a bit of help. If you are ready to start feeling energized and refreshed every day, these tips will show you how this can be achieved:
Find Your Ideal Sleep Pattern
While there are guidelines on the recommended amount of sleep adults should get each night, everyone is individual, so the amount of sleep you need may differ slightly. Many people struggle to get enough sleep, which can leave them exhausted and in a bad mood the following day. Conversely, getting too much sleep can also be a problem and potentially cause some severe illnesses and leave you feeling lethargic. So, finding a sleep pattern that works for you and helps you to wake up each morning feeling refreshed and energized is invaluable.
Nurture Your Skin
Feeling energized and full of vitality happens on the inside and outside. Nurturing your skin with rituals such as a regular facial treatment or body massage can help you to feel refreshed. The cleansing effect of a facial is an especially powerful tool in helping you feel refreshed as areas of congestion are eliminated and dead skin cells are removed, leaving you with nourished skin that feels new. Making facials and massages a regular ritual to support your wellbeing is an excellent way to enjoy the benefits in the long term and will make you feel refreshed after every session.
When your energy levels are low, it can be hard to find the motivation to exercise. But, exercise is vital to providing your body with an energy boost and helping you to feel vital and refreshed. Whether you love sport or hate it, finding a method of keeping fit that you enjoy is essential. If playing sports is not your thing, reconnecting with yourself through yoga is an excellent way to enjoy the benefits of movement combined with the positive effects on your wellbeing. Yoga has the unique ability to make you feel refreshed and energized while at the same time deeply relaxed. Discovering the benefits of yoga for yourself and how it can make you feel is an excellent way to increase your energy levels every day and stay refreshed.
It will be a long and complicated process when it comes to having a more positive outlook on life, your health, and you in general. People are hardwired to be negative and societal expectations also make people (especially women) feel bad for themselves. It’s far too difficult to fight this, but it can be done. Sure, sometimes a person isn’t going to feel the best about themselves or feel good about their situation. This can be hard to avoid. But for your mental and physical health, it’s vital to better look into ways to change your perspective into something more positive. Here are some ways to do it.
1. Be more optimistic
This is usually the first tip when thinking more about the bright side, but it’s true. Yes, it seems lazy, but this can be the most rigid tip. You’ll need to force yourself to be optimistic at first. It’s not easy to do, but it can be done. Some people will even look into gratitude journals and gratitude apps to help them improve their optimism.
2. Focus on the best for yourself
There isn’t anything wrong with focusing on yourself. Sometimes, to help others, you need to allow yourself first. This is a significant step in changing your perspective; you’ll need to think of yourself and how you can put yourself first in some situations. There’s no shame in this; make sure you don’t forget that. You know what’s best for yourself compared to anyone else. So, make sure you keep that in mind.
3. Keep your mind open to new possibilities
When looking toward the bright side and changing your perspective, you should always keep an open mind. Who knows what beautiful possibilities could come your way if you keep a more open mind? Honestly, keeping an open mind will help you continuously change your mindset to think more on the bright side. So, make sure you put that heavily into consideration.
4. Have a positive attitude about everything you do
One of the biggest reasons people struggle to see the bright side in life or even see the bright side amongst themselves is their lack of self-esteem. This can be difficult even more difficult if you have low self-esteem. However, you’ll need to charge back your self-esteem and bring a more positive attitude, especially regarding yourself. So, one thing you can do is challenge your thoughts.
If you are beginning to think something terrible will happen, immediately challenge it. Why is something wrong going to happen? Why would it? Make sure to use logic rather than your personal feelings when you challenge these negative thoughts. This is going to eventually make a big difference in how you’re going to feel about yourself. Adjusting to this will take some time, but do not skip this.
5. Set realistic goals for yourself
When it comes to seeing the silver lining, the bright side, the positive, or whatever you want to call it, it’s also going to be about setting realistic goals for yourself. Even if you feel like you have hit rock bottom, you can still find ways to help yourself. You can get out of this. It just may take time. But one way to help is by setting realistic goals for yourself. This can significantly help you because being practical will help you better strategize what can be done.
Practice Yoga and Functional Movement with Hope For FREE over on her YouTube Channel: SUBSCRIBE TO MY CHANNEL:
What is your relationship with yourself?
It may seem like an odd question as most people tend to focus on their relationships with their loved ones or their friends. Yet, believe it or not, according to expert therapists, the relationship we have with ourselves is disintegrating at an alarming rate. Self-esteem issues are more and more frequent, with approximately 85% of people worldwide struggling with low self-confidence. In other words, the relationship you have with yourself is likely to be bad, according to statistics.
Why don’t we love ourselves more? According to Baumeister, our concept of self is our understanding of our personal attributes. The better we understand ourselves, the more likely our self-confidence and sense of self-worth remain intact.
Unfortunately, self-confidence develops in young age, during childhood and adolescence. Therefore, the interactions you have with your parents and social circle at that age will impact your perception of yourself and, in turn, your self-confidence. Children who receive recognition for both their mistakes and their achievements are likely to develop into confident adults with healthy self-esteem. On the other hand, if parents expect their child to achieve an impossible level of perfection and are fast to criticize any mistakes, the child is prone to feel inadequate, not good enough, and not worthy of self-love.
If you’ve grown up in a situation where you have received unfair criticism, you probably find it tough to make peace with some of your personal attributes. But it is never too late for a wake-up call. Learning to love yourself starts today.
Unsplash – CC0 License
Recover from criticism about your physical appearance
Have you grown up being the chubby kid or the one with the uneven smile? Being at the receiving end of hurtful jokes, even from friends and family, can make it hard to make peace with your appearance. So, it is important to find an objective interlocutor to discuss your worries.
Indeed, if you have experienced people making fun of you for some of your physical features, it can be incredibly difficult to see the real you behind the painful comments. For example, someone who might have been on the heavy side during their school years may still see the image of their old overweight self in the mirror, even though they have long lost all the excess weight. So, the first step in healing your self-esteem is to find someone who will be honest with you and help you. Reaching out to a specialist, such as asking a dentist about your smile, is the surest way to hear an objective answer. More importantly, a specialist can also help you understand your options if you wish to improve features you are uncomfortable with. For example, a dentist could recommend using composite bonding to cover chipped teeth. Making peace with your appearance doesn’t necessarily mean accepting traits you are unhappy about. Things can be changed, and transformations have proven to be instrumental in re-learning self-love.
The last few years have been a rollercoaster for the world. Looking more specifically at the work landscape – so much changed almost overnight.
Those who were used to being plugged into their laptops 24/7 at a desk become required to work from home. Companies closed and had to let staff go. Food services had to pivot, and that was just the start.
Work for millions of people is something they have to do, not something they love – or want to do.
That sparkled people to discover what they are passionate about and how they can make it happen. More people are switching to freelance or small business owners than ever.
But that comes with its different stressors.
Photo by Boitumelo Phetla on Unsplash
So how can you, whether you are in the office or at home, find your zen?
If your mornings are high-speed, messy, and rushed, then your day typically follows that path. It isn’t easy to switch to a different morning routine, but it will give you a huge benefit.
Over the space of a few weeks, start to set your alarm a little bit earlier. Of course, you need to go to bed a little earlier too.
Getting up earlier will give you more time to eat breakfast leisurely, drink tea or coffee, pack bags, or even check emails.
The more relaxed you start the day, the less likely you will be on the back-foot all day.
It might seem impossible to be grateful for a job you dislike, but it is an essential part of feeling that zen.
While the job itself might not bring you joy, the money you get paid probably covers some essential bills.
In a time of uncertainty, having a job that appears secure and comfortable is a blessing.
Think about the time that you have outside of work – what you can do with your time.
Being grateful for what you have is a big deal and will give you a feeling of joy.
Do fun stuff
Outside of work, make time to do some fun stuff. Putting love and energy into the time you spend outside of work will give you more calm and joy to add to your job too.
Look for classes in the area that cover topics that you have always wanted to learn. Go bike riding in the local park—Master the art of illustration.
The world is at your disposal, so begin to recognize and understand you can let loose when you aren’t at work.
Much of being unhappy in work stems from anxiety and fear. Tackling those fears head-on can give you more control over how you approach your work life.
If it is a manual job, you feel it isn’t safe enough or that the management doesn’t focus on your well-being.
Just remember that you have the power to call a personal injury attorney, to join a union, or search for alternative work – you have options.
It can be beneficial to talk more about any anxiety you have with work with a therapist, a life, or a work coach.
Reframe the faces
If you resent your bosses, co-workers, and subordinates, that will reflect in your work, your demeanor and will likely lead to animosity.
The faces of the people at work aren’t there to upset you or to attack you – they are all there to do a job too.
Working collaboratively, setting the business or daily goals as your own, and work with people not against them will make the workday flow with ease.
Reframe your current feelings for those you work with to people you share some things in common.
Side projects can be so much fun! Take some time to think about what you want to achieve in life – general goals. It might be that you wish to publish a book, or perhaps you want to own a food truck eventually.
Don’t hold yourself back – dream big.
Then consider what you might need to do to reach those goals. Start small so that it doesn’t cut too much into having time to relax or impact your work.
Doing a side project that makes you happy and gives you joy will make the jobs you don’t want to do so much easier.
And finally, before and after work, even on the busiest of days, take time to take some slow breaths and shake the day off.
The best way to get that calm moment? A Daily Dose of Hope, of course!
We all have had those moments that were life-changing, those words of wisdom that just stuck and truly impacted us, and over the last several years or so I have had many, and I just want to share them with you. These words of advice, thoughts, and ideas have come in all forms and from all kinds, some from others, some from my own insights, but each of these have had a significant impact on me, not because of the power of the words but because of what I was able to do afterward. These are 12 nuggets of advice that have changed my life.
This is just one moment among many moments in your life right now.
I would get so caught up in the mistakes, things I did or didn’t do or the feelings I was having. Time never stops and all things pass, no matter where you are right now it will soon be over.
When something stinks, step back and make sure it’s not you who smells.
We all want to blame others for what we did or didn’t do ourselves; it takes a far bigger person to admit when they are wrong than it does to point the finger.
Kill em’ with kindness.
When in doubt, you can’t argue with kindness.
You have everything you need right now.
I used to hate this saying, but wherever you are right now you are fully equipped to tackle it, just check to make sure you are using all that is available to you.
You can’t change everyone else you can only change yourself.
If you want others to change, be the example first.
Always be willing to have the hard conversations.
Any time I have ever had to have a difficult conversation, and actually had the courage to have it without getting in the way, the outcome has always been for the better.
Never be afraid to be honest, you can’t control how others receive your truth.
We typically fear the truth because we worry about what will happen after, but cleaning up a lie is way more work, because you don’t have to clean up the truth.
One thing at a time.
We want it and want it now, except we first need to enjoy what we have right now.
Life gives you exactly what you need.
Because where you are is exactly where you need to be in order to get where you are going.
Never be afraid to be who you are, as long as you do it in an honest way.
It’s one thing to be you and do it with a thorn in your side, it’s another to do it in a way that encourages others.
Don’t take shit from anyone.
Those that give you shit probably don’t want to deal with their own, press on my friend.
You can change anything at any time, just be ready to deal with the consequences.
We can change anything and not all consequences are bad, many can and are good, but you won’t know any of that until you get up and do something.
As each year passes, I think to myself, how can I be better than I was before? Trying to live in my truth and live the life I want to rather than the life I think others need me to live.
The older I get and the more I experience life and speak my truth, the more I realize that I don’t have any time to waste living in a way that no longer serves me, and sometimes that means radical change, sometimes that means I can finally speak up in a way I never did before, sometimes that simply means that I live and act without fear.
I have watched far too many people, some very dear to my heart, live their lives in fear, and because of that they never went after what they desired or what they felt that life was asking them to. I have watched many make excuses as to why they made and are currently making the choices they are; but in the end, sadly, I dismay that they will not get where they are going because they simply won’t allow themselves the right to live boldly, in their own truth, because they fear what will happen to those around them and to themselves as they step into their own light.
I refuse to live that way and although I don’t know exactly where life will take me, I know where I am right now and have cultivated enough wisdom and honesty to step back and fully take advantage of the situations in front of me because although I do believe that life gives you exactly what you need, it’s your choice what you decide to do with it.
With that, I welcome the new year and hope that 2021 provides us with new hope and that we live our best lives and stay true to our true selves. | <urn:uuid:8a33fa7c-4e5b-4454-8b21-047d2e9b452d> | CC-MAIN-2022-33 | https://hopezvara.com/tag/inspiration | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.966852 | 3,851 | 1.757813 | 2 |
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Question № 1
How often should you turn a non-traumatic victim to the other side after laying him in the recovery position?
Question № 2
You notice shortness of breath in a child. There is no one around to help. Which of the following actions should be taken?
Question № 3
What should you do in the case of nose bleeding?
Question № 4
What should be preceded by chest compressions in an infant that has been placed on a table or the floor?
Question № 5
Which of these symptoms indicate rib fracture in a conscious victim?
Question № 6
A victim has a closed fracture of the lower limb and complains of severe pain. He is waiting for the arrival of the medical rescue team. What actions should be taken by a witness to the incident?
Question № 7
What should you do if you suspect a cervical spine injury and lack of breath in the victim of a road accident?
Question № 8
In which situation, do you not use an automatic external defibrillator (AED) on a victim?
Question № 9
What should you do if as a result of a traffic accident, fuel leaking from the damaged vehicles gather around the tram?
Question № 10
You drive a rail vehicle. How will you behave when you notice a fire in the electrical installation?
page 1 of 2 | <urn:uuid:a57e9996-e0d9-424c-b2ea-e066f8d5370c> | CC-MAIN-2022-33 | https://pj.oskduet.pl/en/pytania/blok/PD10/1 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.917988 | 308 | 2.0625 | 2 |
Tens of thousands of South African healthcare workers are on the frontline of the global war against COVID-19. Many are in the unenviable position of fighting the pandemic, at the risk of their own lives and those of their families.
SABC News captures their voices in this weekly feature, COVID-19 Frontline Workers. This week, Digital News producer Lebo Tshangela (LT) speaks to Sister Eldah Radebe(ER), who owns a clinic in Freedom Park, Soweto, about her and her staff’s experience with the coronavirus on day 21 of the nationwide lockdown.
LT: South Africa’s lockdown began on March 27, but healthcare workers are among those who provide essential services. I asked Sister Radebe how she feels about having to work during the lockdown.
ER: It’s scary and I feel unprotected.
LT: Dozens of healthcare workers have contracted the COVID-19 virus in different parts of the country. In one of the worst cases, St Augustine’s Hospital in Durban, closed its doors after more than 40 staff members tested positive. Two more cases of mass infections have since been reported in a Mediclinic in Johannesburg and Netcare Kingsway, south of Durban. Sister Radebe says she dreads contracting COVID-19.
ER: My fear is that I will contract this disease, especially because I don’t have protective clothing. I went to many shops. They say the protective clothing is finished, even where we buy our medication. If you find it [then], it’s very expensive.
LT: With the growing demand for Private Protective Equipment amid the pandemic, there is a universal shortage. In one example, a report in the Washington Post reports the US government’s emergency stockpile of respirator masks, gloves and other medical supplies is running low and is nearly exhausted, while on Tuesday, South Africa received medical equipment from China. Among other things, the donations included masks, medical protective gowns and disposable gloves. As an owner of a medical facility, Radebe says, she is directly affected.
ER: We are calling on government to assist private clinics with Private Protective Equipment, such as gloves and masks as we have a lot of clients and we need to be protected. We don’t know who has tested positive for COVID-19 or not.
LT: While many companies have had to rethink the way they work, by either setting up remotely or putting a pause on operations, the healthcare field is even busier. However, according to Sister Hadebe, this has not necessarily been good for business. She says her practice has to juggle with assisting the needy and dealing with employees’ own fears which have affected their professionalism.
ER: The challenges are that I’m rendering a private service but if people are not working you can’t refuse to treat them and turn them away. Most of my clients are street vendors and they come to me and say, ‘I’m having flu but I don’t have money’, what do you think I can say to them? ‘no go home because you don’t have money. They don’t have it. The only clinic we have in the area is Freedom Park Clinic and it’s always full, so people rush to me and they can’t afford to pay for the services. I will give them everything but I’m not going to be compensated. In other words, I’m working at a loss. Some people who are working with me say they cannot come because they are scared of contracting the virus as there are no protective clothes. I can’t force them to come.
Government efforts for protective equipment
With hospitals and clinics at the centre of the fight against COVID-19, government has had to work towards ensuring their protection. Efforts to do so include the massive mobilisation of South African business, labour, academics and government agencies – which have been called upon to build stocks of medical and other equipment needed to fight coronavirus. President Cyril Ramaphosa told the nation on Thursday that R1-billion had been donated to the Solidarity Fund to purchase relevant equipment.
South Africa’s COVID-19 responses in stages
Related: Part 1 COVID-19 Frontline Workers: Q&A with a South African doctor
Related: Part II COVID-19 Frontline Workers: Nurses share stories | <urn:uuid:37d21feb-0c3c-4a5a-b407-3e9d818bfe72> | CC-MAIN-2022-33 | https://www.sabcnews.com/sabcnews/covid-19-frontline-workers-private-clinic-owner-shares-her-story/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.967877 | 936 | 1.625 | 2 |
In recent years, mysterious craters have appeared in the Russian province of Siberia. Some are more than 1 kilometer (0.6 miles) wide and 85 meters (278 feet) deep. Scientists suspect the giant holes might be caused by thawing permafrost.
Permafrost is soil that stays frozen for years. Parts of Siberia have been frozen for 100,000 years, but climate change is thawing them out. Craters may form when large pockets of buried ice melt, causing soil above the ice to collapse. Another possibility is that methane gas frozen in the soil may explode as it thaws, says ecologist Ben Abbott of Brigham Young University. Methane is a powerful greenhouse gas. As it’s released from the soil into the atmosphere, it traps heat, causing more warming. | <urn:uuid:8662e695-cfa8-461c-9b74-d7eab6f49e04> | CC-MAIN-2022-33 | https://scienceworld.scholastic.com/issues/2017-18/103017/mystery-craters.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.953928 | 166 | 3.921875 | 4 |
A guest post from Prof. Boaz Atzili:
Let’s talk about Jerusalem.
The most import fact to remember is that recognizing Jerusalem as the capital of Israel does not mean recognizing Israel’s sovereignty over the eastern part of the city, and it does not mean that Jerusalem cannot be the capital of the Palestinian people as well.
1) Is Jerusalem the capital of Israel? Israelis know it is, and West Jerusalem is the seat of the government and the Israeli parliament, the Knesset. In practice and as a matter of fact, this has been the situation for almost 70 years, since 1948.
Legally, the only base to claim that Jerusalem is not the capital of Israel is the UN Partition Plan of November 1947. In that UN resolution, Jerusalem was supposed to be an international enclave, neither Israeli nor Palestinian. The Palestinians and Arab states utterly rejected that plan in 1947 and instead chose to fight against what they saw, perhaps justifiably so, as an unfair and biased resolution.
After the War of Independence (for Israelis) or the Nakba (for Palestinians) ended in 1949, nobody seriously considered the Partition Resolution as a viable plan for the future of the land. The majority of UN members recognized Israel in its post-war boundaries, as was the custom of the day, but left the status of Jerusalem open for future negotiations. All the Arab states, who rejected these factual borders, instead insisted that Israel as a whole is illegal, not that it should return to the Partition borders.
In all previous rounds of peace negotiation, no party demanded that West Jerusalem become an international enclave. It is clear to anybody with some sense of appreciation of reality that this is an irreversible fact, like many forceful territorial changes of centuries past. West Jerusalem hence is and should be the capital of Israel.
2) But is also a fact that East Jerusalem’s status is different. It was conquered by Israel in the 1967 war, at the time when international norms about legitimate conquest had already changed dramatically since the late 1940s. By 1967 it was no longer an acceptable practice to change state borders by force. It’s important to note that this was the case not only in international law, but in practice. Hence the occupation of East Jerusalem (like other Arab territories) was not, and is still not, recognized by the international community.
Moreover, despite the massive Israeli building in East Jerusalem and despite the constant rhetoric about “the eternally unified Jerusalem,” the city is not unified. For 50 years, Israel failed to create a city that functions as one whole; the government of the city discriminates against some of its residents based on nationality or religion. And Palestinians feel as strongly attached to East Jerusalem as their capital as Israel feels to theirs. Jerusalem is not a united city, and anybody who lived there can attest to that reality as well.
3) So whatever the US President declares on Wednesday, those twin facts, that West Jerusalem is Israel’s capital, and the East Jerusalem will be the Palestinian capital, will not change. Arguing that Jerusalem is not the capital of Israel, or that the city is eternally united (presumably under Israeli authority) are both wishful thinking. And in the Middle East, often wishful thinking results in violence.
All of the above does not mean that the US should not be sensitive to the potential violent consequences of a declaration of recognition, or that it should not consider the right timing. Ideally, such a declaration should be done in conjunction with a significant advance in the peace process. But let’s be serious: Jerusalem— united or divided— is and should be the capital of Israel and a Palestinian state. | <urn:uuid:2af454a3-8512-4a1d-8b60-3aa583b2857b> | CC-MAIN-2022-33 | https://mideastmatrix.wordpress.com/?taxonomy=link_category&term=mavi-marmara | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.956446 | 757 | 2.375 | 2 |
Read the whole article from VNUNet about SMB sentiment. IMHO, much of it comes from FUD in articles and discussions. Hackers and news outlets don't help. They love to scream FUD. (News outlets think their job is to scare people; I thought it was to provide a world view of happening, you know, news!) No one wanted cell phones, because call quality sucked (still does) and fear of tumors. Today, you couldn't wrestle a Blackberry from its owner's cold dead fingers. VOIP needs to stop trying to replace landline and become a better solution for communication. (HD sound may help that; ringtones too. Maybe using that VOIP phone screen for more than just caller ID. And of course security will need to get better on all networks.
If you have SMB clients and they're not talking to you about security, you might want to get a little proactive about it. A new IDC study conducted for the CTIA found that out of 350 companies with fewer than 500 employees, only about half trust VoIP security. Contrast that to 82% for legacy systems, 72% for Ethernet networks, and 60% for WLANs (which really are vulnerable).
Why the bad rap? Fear. People, the study found, are highly attuned to disruptions in voice communications, presumably because phone systems have always seemed bulletproof.
Saturday, January 20, 2007
Fiercevoip is claiming: "SMBs think VoIP is less secure than wireless LANs" | <urn:uuid:d69129a6-fbd7-40ab-a343-44fcd85b8d84> | CC-MAIN-2022-33 | https://www.onradsradar.com/2007/01/voip-is-less-secure-than-wlan.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.971028 | 315 | 1.914063 | 2 |
Are you seeking an opportunity to work with a leading supplier to the automotive industry who offers excellent opportunities for growth and development and a diverse training program to help you reach your full potential? Our client is seeking a Manufacturing Engineer for their Charleston, South Carolina facility.
The primary function of this role is to provide technical expertise for solving all types of process issues and to act as a primary contact with the end customer for any and all production issues. The primary goals are to support the improvement of plant metrics such as downtime, customer PPM, and defects.
- Lead continuous improvements and provide technical expertise solving process problems.
- Troubleshoot equipment and part defects. Implement corrective actions quickly and effectively.
- Manage process documentation such as work instructions and setup instructions.
- Optimize the manufacturing processes to improve quality and material flow, while reducing cycle times.
- Work with the Process Planning team during development and launch of new equipment, tooling, and processes.
- Provide training for new and modified processes.
EDUCATION AND/OR EXPERIENCE:
- B.S. in Engineering required, Mechanical\Electrical preferred.
- Exposure to the manufacturing environment required; automotive manufacturing experience preferred.
- Experience 0-10 (open to recent grads)
- Experience with the development, installation, and maintenance of manufacturing equipment and processes.
- Ability to troubleshoot problems quickly and effectively implement short and long term counter measures.
- Intermediate knowledge of PLC programming preferred.
- Understanding of lean manufacturing, JIS, OEE, line sequencing, KANBAN, etc. a plus.
- Ability to lead cost focused solutions to manufacturing issues.
- Strong interpersonal skills and organizational aptitude.
- Excellent written and oral communication skills.
- Must possess strong computer skills (Excel, Powerpoint, Word, etc.). | <urn:uuid:022fe753-5791-48aa-9134-cd230facb794> | CC-MAIN-2022-33 | https://www.gmarecruiters.com/jobs/manufacturing-engineer-charleston-sc-usa/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.898109 | 396 | 1.53125 | 2 |
In honor of Asian American / Pacific Islander (AAPI) Heritage month, we reached out to the directors of three AAPI led organizations supported by WKKF. Through these conversations, we learned that solidarity and collaboration were the watchwords of a year with deeply complex challenges.
This spotlight features Tha Par, executive director of the Burma Center in our hometown of Battle Creek, Mich.
The COVID-19 pandemic immediately impacted the Burmese community of Battle Creek. Many Burmese community members here are essential workers, who didn’t have the luxury of social distancing, so infection rates rose quickly. The Burma Center rapidly reached out to partners across the city who were also scrambling to respond.
“With all the racial tension in our country, people wonder why we’re only serving Burmese people. They ask: isn’t that reverse discrimination?” says Par. “The pandemic highlighted that when there’s an emergency, it’s critical that our community is taken care of. If we neglected the high infection rate within the Burmese community, it would have impacted everyone else who lives in Battle Creek.”
Their first order of business – take care of the necessities of life. There was a mask shortage to address, so the Burma Center drew on local talent to collect donations, hand-sew and distribute as many masks as possible. At the same time, they worked to ensure everyone could access information around COVID testing, unemployment benefits and food availability in the many languages and dialects spoken within the Burmese community.
They called on local physicians to help spread information about the virus. Dr. Mar and Dr. Oo gathered and presented information to the Burmese community, while Dr. Van Enk, director of infection prevention and epidemiology at local Bronson Healthcare spoke at a webinar for local students. Par points out: “For the students to be able to ask questions about the thing that is turning their lives upside down was really important.”
As anti-Asian attacks began to make headlines, the Burma Center also drew on the Battle Creek Police Department and local Sheriff’s department to host webinars around what to do in the case of hate crime or assault. Participants were provided with information about their civil and human rights, and the proper channels for reporting crimes.
Par says, “We wanted our community to feel supported, rather than taking things into their own hands. Luckily, we didn’t end up dealing with hate crimes here. But, at least our community knows, they can always turn to the Burma Center if they need help or protection.”
In the Fall of 2020, they launched a virtual tutoring program to ensure children didn’t fall behind in learning due to language or technical barriers. The Battle Creek Public Schools (BCPS) officially contracted The Burma Center to continue this service over the winter and the Binda Foundation provided a grant. They hired college students who were looking for work to meet with kids three times a week. In addition to tutoring, the college students were trained to perform health and wellness checks, to ask questions about home and family life to ensure everyone was okay. With support from BCPS and the Binda Foundation, they were able to serve 70 students.
Students even held a virtual piano recital, with keyboards and lessons provided by The Gilmore, another local WKKF grantee.
For Par, there’s been one underlying message in this past year of collaboration:“The importance and interconnectedness of all of us, the pandemic has definitely taught us that.” | <urn:uuid:dd92c185-da5e-40d6-9187-04c2e218a8a0> | CC-MAIN-2022-33 | https://everychildthrives.com/being-the-lifeline/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.961003 | 750 | 1.882813 | 2 |
In November 2021, Microsoft and AT&T announced the launch of Azure public MEC (multi-access edge compute) with a site in Atlanta, Georgia. The Azure public MEC solution enables low-latency applications at the edge of the mobile operator’s network, providing Azure compute services integrated with 5G connectivity. Azure public MEC is designed to run AI and machine learning workloads that require intensive compute and low latency network. The access to these resources is over high-quality 5G connections from phones, smart cameras, IoT devices, and other equipment. Enterprises and developers can build and run these low-latency applications and manage their workloads using the same tools they are using to run applications in the Azure public cloud.
To light up new compelling applications with Azure public MEC that benefit from low latency 5G connectivity, we are making available a video analytics library under the umbrella of Edge Video Services.
Edge Video Services
Edge Video Services (EVS) is a Microsoft platform for developing video analytics solutions that can be deployed on Azure public MEC. For example, consider some smart city applications like our Vision Zero work with the City of Bellevue, which enabled a new generation of real-time traffic flows leading to substantial improvements in the day-to-day lives of commuters. Similarly, real-time video analytics can make cities safer by controlling traffic lights for situations such as allowing a person in a wheelchair to safely cross the street. A related application, which we demonstrated at Hannover Messe 2016, integrated an early version of EVS into traffic light cameras and those in self-driving cars to analyze videos to help reduce accidents and fatalities. Other new applications that are coming soon include improving transportation systems, monitoring air quality, street lighting, smart parking, crowd management, and emergency management. Beyond smart cities, EVS can provide modern smart enterprises with end-to-end experiences with video analytics for mixed reality as a natural component of 5G network solutions. Additional examples include managing machines and robots in connected factories, handling customer demands and services in retail stores and restaurants or tracking pedestrian traffic in sports arenas.
As shown in Figure 2 below, 5G compute infrastructure has a hierarchy of intelligent components including Azure Percept devices, Azure private MEC, and Azure public MEC. EVS integrates with all of these solutions and provides these features:
- Inter-edge orchestrator to manage network traffic involving multiple public MECs. It deploys application containers across the edge hierarchy for high availability and fault tolerance.
- Network monitoring and adaptation to continuously monitor the dynamic wireless and wired network connections, adapting application demands accordingly.
- Dynamic resource allocation for video machine learning containers. This adapts based on the load generated from the mobile network and the workloads deployed in the on-premises edge location.
Smart cities deployment at Azure public MEC with AT&T in Atlanta
Working with AT&T, Microsoft demonstrated the value of EVS on the Azure public MEC connected to the AT&T’s 5G network in Atlanta. The setup consisted of an on-premise edge device, managed by Azure IoT Hub and an Azure Kubernetes cluster as shown in the diagram below.
The EVS orchestrator places the various containers across the on-premises edge and Azure public MEC. This split execution brings the benefits of a “heavy” edge to the application without the need to either deploy such a heavy edge on the premises or provision a hefty bandwidth connection out of the on-premises edge.
In our Atlanta deployment, we demonstrated EVS’s split architecture, with lightweight execution at the on-premises edge. It transferred 230MB of data over the 5G link out of the on-premise edge over 24 hours, by contrast, 9.5GB of data would have been sent if all the encoded video were transferred out. In other words, EVS reduced the network utilization by 42x. This network saving was obtained with a CPU-only edge on-premises with no loss in accuracy. Our measurements also showed that network latencies to the Azure public MEC were about 6x lower at the median compared to the nearest Azure region, which translated to faster responses for the application.
EVS is integrated with AT&T’s network APIs to obtain real-time information about the 5G network. As a result, EVS adapts the amount of traffic transferred between the edges, depending on any fluctuations to the latency and bandwidth of the 5G link. EVS uses Azure Traffic Manager to support automatic failover for the Azure public MEC to the nearest Azure region, thus ensuring no disruption to the video application. When failing over to the Azure region, EVS adapts to the changed and increased latency by adjusting the amount of traffic sent out of the on-premises edge via changes to the encoder and machine learning model parameters with minimal impact on application accuracy. EVS is also cognizant of other containers executing at the edges and can elastically scale up or down its compute requirements.
EVS on Azure public MEC: Try it out today
For your video scenarios, we encourage you to try out EVS on Azure public MEC with your own on-premises edge devices. The reference architecture and instructions are available in our GitHub repository. The repository also includes a sample video of cars entering a parking lot that you can use to test EVS for counting cars. To submit feedback about EVS, please email to evs-support@microsoft. Please note this is only for submitting feedback, you will not be contacted.
Source: Azure Blog Feed | <urn:uuid:4d5f6208-e365-49ce-9478-5165d62679aa> | CC-MAIN-2022-33 | https://www.mashfords.com/2022/05/17/microsoft-and-att-demonstrate-5g-powered-video-analytics/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.914876 | 1,148 | 1.585938 | 2 |
Cast iron is difficult, but not impossible, to weld. In most cases, welding on cast iron involves repairs to castings, not joining casting to other members. The repairs may be made in the foundry where the castings are produced, or may be made to repair casting defects that are discovered after the part is machined. Mis-machined cast iron parts may require repair welding, such as when holes are drilled in the wrong location. Frequently, broken cast iron parts are repaired by welding. Broken cast iron parts are not unusual, given the brittle nature of most cast iron.
While there are a variety of types of cast iron, the most common is gray cast iron, and these guidelines are directed toward this type of material.
A few facts about cast iron help in understanding the welding challenges. Cast iron typically has a carbon content of 2% - 4%, roughly 10 times as much as most steels. The high carbon content causes the carbon to form flakes of graphite. This graphite gives gray cast iron its characteristic appearance when fractured.
When castings are made, molten iron is poured into a mold and allowed to slowly cool. When this high carbon material is allowed to cool slowly, crack free castings can be made. Remembering this is helpful when welding cast iron: during and after welding, the casting must either be allowed to cool slowly, or should be kept cool enough that the rate of cooling is not important.
A critical temperature in most cast iron is about 1450 degrees F. When at this temperature, conditions that can lead to cracking occur. While the arc will heat the casting to temperatures above this level, it is important that the casting not be held at this temperature for long periods of time.
If the part is to be machined after welding, a nickel-type electrode will be required. Use Tech-Rod® 99 stick electrode for single pass, high dilution welds. Tech-Rod® 55 is preferred for multiple pass welds. Sometimes, root passes are put in with Tech-Rod 99, followed by fill passes with Tech-Rod 55. For welds where machining is not required, and where the weld is expected to rust like the cast iron, Lincoln Ferroweld® stick electrode can be used.
To Heat, or not to Heat
In general, it is preferred to weld cast iron with preheat--and lots of it. But, another way to successfully weld cast iron is to keep it cool--not cold, but cool. Below, both methods will be described. However, once you select a method, stick with it. Keep it hot, or keep it cool, but don't change horses in the middle of the stream.
Welding Techniques with Preheat
Preheating the cast iron part before welding will slow the cooling rate of the weld, and the region surround the weld. It is always preferred to heat the entire casting, if possible. Typical preheat temperatures are 500-1200 degrees F. Don’t heat over 1400 degrees F since that will put the material into the critical temperature range. Preheat the part slowly and uniformly.
Weld using a low current, to minimize admixture, and residual stresses. In some cases, it may be necessary to restrict the welds to small, approximately 1-inch long segments to prevent the build up of residual stresses that can lead to cracking. Peening of weld beads can be helpful in this regard as well.
After welding, allow the part to slowly cool. Wrapping the casting in an insulating blanket, or burying it in dry sand, will help slow cooling rates, and reduce cracking tendencies.
Welding Techniques without Preheat
The size of the casting, or other circumstances, may require that the repair be made without preheat. When this is the case, the part needs to be kept cool, but not cold.
Raising the casting temperature to 100 degrees F is helpful. If the part is on an engine, it may be possible to run it for a few minutes to obtain this temperature. Never heat the casting so hot that you cannot place your bare hand on it.
Make short, approximately 1” long welds. Peening after welding is important with this technique. Allow the weld and the casting to cool. Do not accelerate the rate of cooling with water or compressed air. It may be possible to weld in another area of the casting while the previous weld cools. All craters should be filled. Whenever possible, the beads should be deposited in the same direction, and it is preferred that the ends of parallel beads not line up with each other.
Because of the nature of cast iron, tiny cracks tend to appear next to the weld even when good procedures are followed. If the casting must be water tight, this can be a problem. However, leaking can usually be eliminated with some sort of sealing compound or they may rust shut very soon after being returned to service.
The Studding Method
One method used to repair major breaks in large castings is to drill and tap holes over the surfaces that have been beveled to receive the repair weld metal. Screw steel studs into the threaded holes, leaving 3/16” (5 mm) to ¼” (6 mm)of the stud above the surface. Using the methods discussed above, weld the studs in place and cover the entire surface of the break with weld deposit. Once a good weld deposit is made, the two sides of the crack can be welded together.
View more Cast Iron Welding How-To articles
View Cast Iron Stick Electrodes | <urn:uuid:3b851d88-08eb-40b5-b83e-5fbb3d035551> | CC-MAIN-2022-33 | https://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/welding-cast-iron-detail.aspx?utm_referrer=direct/not+provided | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.934955 | 1,158 | 3.21875 | 3 |
The Number 666 – A Blessing in Disguise?
The number 666 has been linked to scary scenes and hideous demonic beasts which have spooked the fraught nerves of the laity for almost two thousand years. Superstitions have abounded at the sight of that ominous number - it was viewed as a symbol of the devil and every vile tyrant who ever stalked the earth, beginning with the Roman Emperor Nero. You may be glad to hear that the terrible evil image of the number is at an end.
I have discovered that the number 666 was a compass which pointed to the most sacred rituals in the Old Testament – a place where wonderful knowledge of the heavens lays hidden.
What is Behind the Menacing Façade?
We can at last analyze the number 666 in the context in which it was quoted and look at what lay behind the menacing façade. The quote about 666 was in the Book of Revelation and it read as follows:
“Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six.” (Rev. Ch. 13:18)
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‘The Number of the Beast is 666’ (1805) by William Blake. ( Public Domain )
It stated that 666 was the number of the beast and also the number of a man. It was strange how the opening phrase was a declaration of wisdom and in the Bible it was identified with King Solomon who was renowned for his wisdom. The second phrase in the quote about 666 stated “let him who has understanding,” There was a similar phrase relating to Solomon in the first Book of Kings where it stated that “God gave Solomon wisdom and understanding exceedingly much.” (First Kings Ch. 4:29) As you can see the two similar phrases would suggest that Solomon was the intended target.
Have you heard of a biblical search engine? It is like an internet search engine but it allows you to look up the listings of particular words or numbers instantly in the Bible. I entered the number 666 into the search engine and lo and behold it stopped with King Solomon , where it stated as follows:
“Now the weight of gold that came to Solomon in one year was six hundred threescore and six talents of gold.” (First Kings 10:14)
The number 666 was listed with Solomon, albeit as gold treasure. I hit the return key again and the search engine stopped in the second Book of Chronicles where it repeated about the weight of gold that came to Solomon in one year as six hundred and threescore and six talents of gold. (Second Chronicles Ch. 9:13) Thus, a firm link to Solomon and wisdom had been established with the number 666.
God promises Solomon wisdom in a dream. ( Public Domain )
I hit the return key again and the search engine stopped in the Book of Ezra where the verse listed the number of men who returned from exile in Babylon as follows: “The children of Adonikam, six hundred sixty and six.” (Ezra 2:13) The numbers of the children of a man named Adonikam who returned to Jerusalem were 666. We therefore have linked 666 with Solomon via the word wisdom and have also seen it was the number of a man named Adonikam.
Discovering ‘The Beast’
The next part of the quest is to identify why it was called the number of the beast. Immediately following the listing of 666 in the Book of Revelation the text referred to a lamb on Mount Sinai and four beasts. There was also a reference to the word “Firstfruits” in the verses . I entered the word Firstfruits into the search engine and one of the places where it stopped in the Old Testament was in Chapter 28 of the Book of Numbers. It turned out that the Firstfruits was a ceremonial feast offering and it involved ritual sacrifice. And guess what was offered for sacrifice? It was four beasts. Those beasts were bullocks, rams, lambs, and goats. The link to those four beasts was strengthened as it particularly stressed that all of the beasts were to be “without blemish.” In comparison, the four beasts in the Book of Revelation were “not defiled” and “without fault.”
There were many more sacrificial offerings of bullocks, rams, lambs, and goats made by Moses and they were all outlined in great detail in Chapters 28 and 29 of the Book of Numbers. Those sacrifices were made on the anniversary of the Passover and on the First Day of the month and on many other different days of the month. The number 666 was quoted as ‘the number of the beast,’ but how could it relate to all of those different animals or beasts which were sacrificed? Because the number of the beast was outlined in the singular term of ‘beast’ rather than the plural with ‘beasts,’ it was possible that the number indicated the presence of what is known as a checksum.
Icon of Cain and Abel offering their sacrifices to God. The Greek Catholic church of the Exaltation of the Venerable Cross. Bratislava, Slovakia. 2019/10/20. ( Adam Ján Figeľ /Adobe Stock)
A checksum is where lists of individual numbers or items are all added up together and their combined total is a quick number to check later if there is still the same number of items. A simple example of a checksum is where the guide on a tour bus counts the number of people who disembark from the bus at a tourist stop and it does not matter if they are men, women, or children. They are all just counted as neutral numbers.
The guide later counts all of the tourists when they return to the bus to ensure that they are all there. If the number falls short of the target, the task is to identify who has not returned by holding a roll call. The checksum therefore is a rapid snapshot method of making sure that the numbers all add up and nobody is left behind.
The target for the checksum was with all of the beasts, which were sacrificed in Chapter 28 and 29 of the Book of Numbers. Therefore, I conducted the sums and it involved multiplications and additions of all of the animals that were sacrificed on all those various days of offerings. It also included fractional weight of flour and oil, which were mingled with the meat of the animals. To conduct that checksum was a nightmare, but I finally worked out the total and it came to 1,997.25.
This result was a tiny fraction less than three times the number 666 at 1,998. The total was relevant since there were three listings of the number 666 in the Old Testament and now three times 666 had emerged as the total number in those sacrificial offerings. It was called ‘the number of the beast’ in singular terms because all of the beasts had been counted in the checksum as neutral numbers irrespective if they were bullocks, rams, lambs, or goats.
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Animal sacrifice in the Bible. (Distant Shores Media/Sweet Publishing/ CC BY SA 3.0 )
The number 666 has proven to be a blessing in disguise where three times that number, at 1,998, acted as a checksum total to prove that all of the individual numbers and fractions in those divine holy offerings in the Book of Numbers had retained their original values intact. How intellectually advanced those biblical mathematicians were in future-proofing the numbers in those sacred offerings. In the process, the number 666 had cast off the evil shroud to step into the light, pure in heart and gentle as a dove.
The Number 666 in the Realm of the Stars
The number 666 also served a second function, and strangely, it involved an equation related to solar time and what is called sidereal time . To understand the equation it is necessary to explain the measurement of time.
Our everyday calendar is based on the solar year and it is measured against a fixed point on earth and it is 365.242 days long. In contrast, the sidereal (‘Sidereal’ is the Greek for star) year is measured against a bright star in the heavens and it is 365.256 days long. Therefore, the sidereal year is approximately 20 minutes 10 seconds longer than the solar year.
Before the invention of mechanical clocks around the 14th century AD it would have been impossible for the ancients to accurately measure the solar and sidereal years. However, the following computations will show that the biblical writers were truly inspired because they knew precisely the length of both solar and sidereal years.
There are three main numbers in the equation, and these are 666 together with the number 1,260 from the Book of Revelation where it was cited as a period in days. (Rev. Ch. 12:6) There is also the number 2,300 as a period of days from the Book of Daniel. (Dan Ch. 8:14) Those three numbers have been the source of every oddball theory for thousands of years with the latter two linked by eccentrics to predicting the future . There was however a real purpose for those numbers, which I found out when I performed the following calculation on a calculator:
When 1,260 days was multiplied by 666 and the result divided by 2,300 days the outcome was 364.852174 days. This result was just a fraction of a day short of the calendar year of 365 ¼ days.
The next step is to show how the biblical writers projected out the difference in time between the solar and sidereal years over the period of one thousand years. In that period, the tiny shortfall multiplied out to just over a period of 13 months. But amazingly, to correct the leap period error involved the calendar periods of one year, one month, one week, one day, and one hour.
All those calendar periods were listed in the Book of Revelation. In Chapter 9 of that book there was the following sentence:
“Which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men.” (Rev. Ch. 9:15)
The sentence listed the normal intervals of the calendar with a year, a month, a day, and an hour. All that was missing was the period of a week. However, the period of a week was cited separately in the context of twice 3 ½ days elsewhere in the book. (Rev. Ch. 11:9, 11)
The sentence above had stated “ for to slay the third part of men” and it reminded me how Moses had three thousand men slain for worshipping the golden calf. One third of those men would be one thousand and so I looked for the number of one thousand in the Book of Revelation. There were six individual listings of one thousand and they were with the periods of 1,000 years. (Rev. Ch. 20) The complete indices of an astonishing equation relating to time had emerged.
‘Worship of the golden calf’ (circa 1560) by Jacopo Tintoretto. ( Public Domain )
The result from the computation in the equation above involving 666, 1,260 days and 2,300 days was 364.852174 days. I then multiplied that result by one thousand and the outcome was 364,852.174 days or almost one thousand years. The next step had the touch of a divine wand where by adding on the periods of one year, one month, one day and one hour as cited in the Book of Revelation, the following result was evident:
The result was 365,248.886 days and it rounded up to 365,249 days.
The period of one week had not featured in the equation because it was listed separately from the other calendar periods. But now the divine wand will sparkle again where one week will be applied to produce two remarkable results. By adding on one week of seven days to 365,249 days, the outcome was 365,256 days. This was one thousand sidereal years to the exact day.
By subtracting the period of one week of seven days from 365,249 days and the result was 365,242 days. This was one thousand solar years to the exact day.
Was this brilliant cosmic equation part of the keys to the kingdom of heaven which Jesus promised Peter? Can you imagine the perseverance the biblical mathematician had to endure in order to identify the three principal numbers of 666, 1,260 days, and 2,300 days in that equation?
‘Christ Handing the Keys to St. Peter’ by Pietro Perugino (1481-82). ( Public Domain )
That the target of one thousand solar years and one thousand sidereal years was achieved with all of the unique elements of the calendar with one year, one month, one week, one day, and one hour was a miraculous feat of inspired numerical engineering.
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666 As a ‘Secret Doorway’
The number 666 has opened up a secret doorway to reveal the first instalments of a sacred calendar system, which was outlined in the equation on solar and sidereal time. It was only the beginning because 666 had also led us to those sacrificial offerings in the Book of Numbers and also Solomon and Ezra where there were similar burnt offerings. It was the number of animals to be slaughtered - which was the real target for they proved to be the indices of a sacred almanac which effectively was the calendar of the gods.
The exercise has shown that the numbers in the Bible were an intelligent part of scripture and they were equally as important as the written word. These initial findings finally led me to identify a magnificent archive of celestial data which formed when the various sets of numbers in the Bible were assembled together like the pieces of a giant jigsaw. The evidence suggests that the celestial data once belonged to the biblical prophets and they had used it to chart out how the predicted Messiah would be born at the time of a bright star over Bethlehem .
The three Magi and the Star of Bethlehem. ( CC0)
The findings have the potential to revolutionize the debate between science and religion. It can provide a dialogue between people and nations, open the eyes of scientists, dazzle skeptics, and empower the clergy who have persevered against the odds.
Top Image: Detail of ‘The Number of the Beast is 666’ (1805) by William Blake. Source: Public Domain
To learn about those biblical wonders, go to Michael Hearns’ website: www.sevenbiblewonder.com. Twitter: @mhearns2018 | <urn:uuid:58cc1ab3-2ef9-46a8-86a7-d4ba9a12fe30> | CC-MAIN-2022-33 | https://www.ancient-origins.net/unexplained-phenomena/666-0013153 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.973163 | 3,165 | 1.90625 | 2 |
Click here to read: “U.N. Faults U.S. for Failure to Prosecute Abusive Clerics,” by Caleb Bell, Religion News Service, Huffington Post, 2/20/2013
Excerpt: Sister Mary Ann Walsh, spokeswoman for the U.S. Conference of Catholic Bishops, said that the hierarchy does a “huge amount” in order to prevent sex abuse within the church — much of it learned after the abuse scandal came to light.
Editor’s note: Those “audits” were taking place before the release of the Philadelphia Grand Jury Report in 2011 and did absolutely nothing to expose the cover ups here or elsewhere in the US. Sister Mary Ann, please wake up. As their spokesperson, you are providing another example of the skirts hiding behind a skirt. This isn’t a problem of the past – it’s ongoing. We can and should educate our children, but if adults don’t do the right thing, it doesn’t matter. | <urn:uuid:76bc283f-3448-4aee-85f3-addfc477ab2b> | CC-MAIN-2022-33 | https://catholics4change.com/2013/02/21/united-nations-faults-us-for-failure-to-investigate-clergy-sex-abuse/?replytocom=23916 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.945458 | 216 | 1.585938 | 2 |
As Dartmouth’s Web Director, my responsibility is to manage and coordinate all development of Dartmouth’s digital environment. Admissions is an important property in that environment. When it came time for a redesign, I persuaded Admissions to work with my in-house group, Web Services, rather than outsource the project.
Having won Admissions as a client over external vendors, I was under pressure to deliver a service that would be comparable. However, because of my broader role at Dartmouth, I had to develop the site within the greater context of the Dartmouth web. The entire process required that I perform a careful balancing act of responding to requests while adhering to institutional standards and meeting user needs.
When it comes time for decision-making in the design process, I have found the best approach is to let users drive the process. User-centered design takes the decision making out of the hands of the designers and stakeholders, and instead allows user needs and preference direct decision-making.
We started the process with usability testing of a range of admissions sites at other institutions. We wanted to see how prospective students approach the process of finding a good match in very different contexts.
In observing about 5–6 high school students it became clear that the process of finding a good school was very similar to that of finding a good partner. Prospective students first determine whether they are right for the school by looking for data, such as average test scores of admitted students. If they pass the “fittedness” test, then they explore whether the school is right for them—the location, whether it offers a major in their field of interest, athletics and arts offerings. If the school passes the test, then they look to the application process.
As a result, our strategy was to provide prospective students and parents with data right up front. The current site has “Facts” front and center, complemented by images, videos, narrative, and stories that demonstrate that Dartmouth students are admitted for more than their ability to do well on standardized tests.
The information design supports the natural process flow, with the “Facts” and “Learn” sections providing ample opportunities for prospective students to determine whether they are right for Dartmouth, and whether Dartmouth right for them. The “Visit” section supports the next phase in the process, providing information and opportunities for both virtual and physical campus visits. And the “Apply” section is the final step in the process, with information and functionality to support prospectives who have decided to take the plunge and become applicants. In April, when decisions have been made and applicants have been notified, the architecture also supports admitted students with a “Class of 20XX” section. The site also has an “Answers” section that answers commonly asked questions.
Supporting these more practical needs is the “Perspectives” section. Here is where we attempt to communicate the richness of the study body through a variety of first-hand perspectives on the Dartmouth experience, through interviews, student blogs, live office hours, and more. This section aims to accomplish a challenging task: to provide authentic stories within the context of an official admissions website. We continually explore which means of communication is the most useful, impactful and, most importantly, credible to prospective students.
The visual design is modeled on a flexible, grid-based layout. I generally build flexible, or “liquid,” layouts, but this was the first time I did so on a grid, and the result provides the best of both worlds. The page elements harmonize, and yet they scale to accommodate different window widths and text sizes. And the line length cannot become too long since the layout is restricted to a generous but readable maximum width.
All of Dartmouth’s sites are built on the same codebase, so the Admissions site uses mostly the same code as, for example, Classics, Budget, and the Office of the President. This architecture allows for site-wide changes, such as the inclusion of an emergency banner on all sites in case of an emergency. It also allows a small team of web professionals to provide support to all Dartmouth departments and programs. On the down side, it limits design options. | <urn:uuid:ce05475e-98cd-419b-a902-57338ab48736> | CC-MAIN-2022-33 | https://sarahhortondesign.com/page/3/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.945465 | 969 | 1.796875 | 2 |
10 Bible Verses about Balances, For Business
Most Relevant Verses
A false balance is an abomination to the Lord,
But a just weight is His delight.
“When will the new moon be over,
So that we may sell grain,
And the sabbath, that we may open the wheat market,
To make the bushel smaller and the shekel bigger,
And to cheat with dishonest scales,
‘You shall do no wrong in judgment, in measurement of weight, or capacity. You shall have just balances, just weights, a just ephah, and a just hin; I am the Lord your God, who brought you out from the land of Egypt.
Differing weights and differing measures,
Both of them are abominable to the Lord.
- Abominations, To God
- Balances, Dishonest Use
- Business Ethics
- Buying and selling
- Covenant breakers
- Deception, Forbidden By God
- Dishonesty Condemned
- God, Will Of
- Just Weights
- Money, Stewardship Of
- Right Measures
- Social duties | <urn:uuid:2cc7d285-9551-454c-84f7-6b3a3fe011e7> | CC-MAIN-2022-33 | https://bible.knowing-jesus.com/topics/Balances,-For-Business | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.877461 | 281 | 1.8125 | 2 |
Google calls “Look and Talk” — which is very amusingly codenamed “Blue Steel” after Zoolander — the “first multimodal, on-device Assistant feature that simultaneously analyzes audio, video, and text to determine when you are speaking to your Nest Hub Max.”
There are three processing phases to every interaction, with Assistant looking for signals like Proximity, Face Match, Head Orientation, Gaze Direction, Lip Movement, Voice Match, Contextual Awareness, and Intent Classification. There are over 100 signals from the camera and microphone in total with processing occurring locally on-device.
Often, a strong enough interaction signal does not occur until well after the user has started speaking, which can add hundreds of milliseconds of latency, and existing models for intent understanding add to this since they require complete, not partial, queries. To bridge this gap, Look and Talk completely forgoes streaming audio to the server, with transcription and intent understanding being on-device.
It starts with the Nest Hub Max determining whether a “user is demonstrating an intent to engage with [Assistant].” They have to be within five feet and be recognized by Face Match, with Google taking care to ignore brief glances at the device.
For an enrolled user within range, an custom eye gaze model determines whether they are looking at the device. This model estimates both the gaze angle and a binary gaze-on-camera confidence from image frames using a multi-tower convolutional neural network architecture, with one tower processing the whole face and another processing patches around the eyes. Since the device screen covers a region underneath the camera that would be natural for a user to look at, we map the gaze angle and binary gaze-on-camera prediction to the device screen area. To ensure that the final prediction is resilient to spurious individual predictions and involuntary eye blinks and saccades, we apply a smoothing function to the individual frame-based predictions to remove spurious individual predictions.
Phase two has the Hub Max start listening, verify Voice Match, and predict “whether the user’s utterance was intended to be an Assistant query.”
This has two parts: 1) a model that analyzes the non-lexical information in the audio (i.e., pitch, speed, hesitation sounds) to determine whether the utterance sounds like an Assistant query, and 2) a text analysis model that determines whether the transcript is an Assistant request. Together, these filter out queries not intended for Assistant. It also uses contextual visual signals to determine the likelihood that the interaction was intended for Assistant.
The third phase, after the first two are met, is fulfillment “where it communicates with the Assistant server to obtain a response to the user’s intent and query text.” This feature involved a wide range of testing:
We developed a diverse dataset with over 3,000 participants to test the feature across demographic subgroups. Modeling improvements driven by diversity in our training data improved performance for all subgroups.
For Google, “Look and Talk represents a significant step toward making user engagement with Google Assistant as natural as possible.” Quick Phrases — where predefined commands (e.g. set an alarm or turn lights on/off) don’t require the hotword — are coming next to the Nest Hub Max.
More on Nest Hub Max:
- Nest Hub Max adds Bluetooth settings menu with Fuchsia update
- At a Glance on Pixel prepares to show timers from Nest Hub and Assistant speakers
- Spotify on Nest Hub can now show real-time lyrics
- How to manage Google Nest Hub alarms through the Home app
FTC: We use income earning auto affiliate links. More. | <urn:uuid:eb9c9473-a14e-4eab-9854-b1b9a4e04843> | CC-MAIN-2022-33 | https://9to5google.com/2022/07/27/google-assistant-look-and-talk/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.909496 | 771 | 2.03125 | 2 |
Chinese New Year 20201
Chinese New Year Holiday.
Chinese new year 20201. Friday February 12 2021-229. Chinese New Year 25 January 2020 - 26 January 2020 Saturday - Sunday Monday 27 January 2020 will be a public holiday if your rest day falls on 26 January 2020. 12 Jun to 14 Jun.
Chinese New Year Holiday. Chinese New Year 2021 animal sign is the White Cow. Chinese New Year Holiday.
Sunday January 22 2023. Chinese New Year 2025. Saturday February 10 2024.
Adopt Me Chinese New Year 2021 UpdateCredits to all original creators of the concepts Disclaimer-Adopt Me has not confirmed any pets for the updates yet. Aside from the Rat and Ox the other. Yee Sang a vegetable medley dish eaten by throwing its pieces high in the air with chopsticks to bring good luck.
Chinese New Year 2022 will fall on Tuesday February 1st 2022. Tuesday February 01 2022. The date of Chinese New Year is determined by the Chinese lunar calendar.
Saturday January 25 2020-613. May Longevity wealth health virtue and a natural death- the five blessings come to you. Year of the Ox.
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- French Bulldog Puppies Palm Beach | <urn:uuid:eb746670-db61-4760-8412-7b5c50041382> | CC-MAIN-2022-33 | https://coolwildlifewallpaper.pages.dev/chinese-new-year-20201 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.835973 | 397 | 1.546875 | 2 |
Responding to high maternal mortality rates, Health Care Service Corporation (HCSC) advocated for a change in federal law allowing state Medicaid programs to extend pregnancy related coverage for a full year after women give birth. We also worked with community organizations to reduce health disparities experienced by women of color.
In Illinois, six community-based organizations working to improve maternal health outcomes on Chicago’s South and West Side neighborhoods received grants totaling more than $350,000. Their programs include a home-visiting program for young mothers, doula services and training and mentorship for women of color specializing in maternal health.
“You have to look at what’s going on and find out why we are failing Black women,” says Cynthia Jacinthe, owner and founder of Dr. Jacynia Women's Care Consulting, and one of Chicago’s Black certified midwives. “We have to change things around.”
In Texas, we supported the March of Dimes’ efforts to end cycles of discrimination experienced by women of color in maternal and infant health care settings. The organization’s implicit bias training is helping providers confront institutionalized racism in the health care system.
To improve vaccination rates, we worked with state health officials in New Mexico and Texas to more accurately determine which members are behind on immunizations for vaccine-preventable diseases, including COVID-19. The data-sharing effort allowed our teams to reach out to members with immunization gaps to provide vaccine education and help them find providers to get caught up.
In Oklahoma, our support helped the Muscogee Nation treat native and non-native Oklahomans with monoclonal antibodies against COVID-19 at the tribe’s Council Oak Comprehensive Healthcare in Tulsa.
“This generous grant will help further the Muscogee Nation’s vision of providing effective treatment to all Oklahomans, regardless if they have health insurance or not,” says Shawn Terry, Secretary of Health for the Muscogee Nation.
Recognizing the importance of supporting kids’ mental health now more than ever, we teamed up with education technology company EVERFI to launch a statewide mental health education program targeting middle and high school students in New Mexico and Montana. The course gives educators proven, effective learning tools to engage their students and have meaningful conversations that can lead to lifelong health improvement.
Our mobile health programs in Illinois, Montana, New Mexico, Oklahoma and Texas collaborate with community partners to deliver immunizations other important health services and information where people live, work, shop and go to school.
The 28 vans — including three added in 2021 — served more than 58,000 clients and provided more than 54,000 immunizations and nearly 41,000 other health services.
In Oklahoma, the Southern Plains Tribal Health Board (SPTHB) used one of the vans as a dedicated mobile clinic to bring preventive health services to tribal citizens.
The programs in Oklahoma and Texas collaborated with community health clinics and school districts to help protect high-risk residents against COVID-19 when the vaccines became available. In New Mexico, the vans helped independent health care providers and community organizations to hold COVID-19 vaccine clinics at two McDonald’s locations.
As public health guidance evolved during the pandemic, we reopened our neighborhood centers in Chicago’s Pullman, Morgan Park and South Lawndale neighborhoods for in-person wellness classes and services after providing virtual-only sessions during the height of the pandemic. More than 8,300 people took advantage of resources offered through the centers, which work to address social determinants of health such as access to quality health care, transportation, stable housing, food security, safe environments and employment.
Community outreach specialists helped expand access to health care coverage during a special enrollment period triggered by the pandemic and during the annual open enrollment period. Team members helped consumers in our states navigate their options by phone, virtually and at in-person events.
We continued to offer marketplace plan options in every county where we operate and also expanded Medicare Advantage offerings to more than 90 new counties. This expansion provided new coverage options to 1.2 million additional Medicare-eligible individuals, particularly in rural and underserved areas. | <urn:uuid:2e66e1a7-6234-4a56-b5ff-c5d3214487f7> | CC-MAIN-2022-33 | https://www.hcsc.com/our-impact/corporate-social-responsibility/access-to-care | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882570741.21/warc/CC-MAIN-20220808001418-20220808031418-00065.warc.gz | en | 0.951567 | 865 | 2.171875 | 2 |
Natural catastrophes last year cost global economies an estimated $210 billion (£155bn).
That’s according to new research by the German reinsurer Munich Re, which suggests the economic damage of natural disasters, including storms, wildfires and hurricanes soared last year, up from $166 billion (£122bn) in 2019.
The analysis showed six-in-ten of the costliest natural disasters happened in the US.
Natural disasters in the US accounted for $95 billion (£70bn) of overall losses and $67 billion (£49.4bn) of insured losses.
Floods in China were responsible for the highest individual loss of $17 billion (£12.5bn), only around 2% of which was insured.
Torsten Jeworrek, Member of the Board of Management at Munich Re, said: “Natural catastrophe losses in 2020 were significantly higher than in the previous year. Record numbers for many relevant hazards are a cause for concern, whether we are talking about the severe hurricane season, major wildfires or the series of thunderstorms in the US. Climate change will play an increasing role in all of these hazards.”
Ernst Rauch, Chief Climate and Geo-Scientist at Munich Re, commented: “An increasing number of heatwaves and droughts are fuelling wildfires and severe tropical cyclones and thunderstorms are becoming more frequent. Research shows that events such as this year’s heatwaves in Northern Siberia are 600 times more likely to occur than previously.” | <urn:uuid:8f442ae6-1537-43a2-a0dc-100d610042b5> | CC-MAIN-2022-33 | https://www.energylivenews.com/2021/01/08/billion-dollar-natural-disasters-natural-catastrophes-in-2020-create-global-economic-loss-of-210bn/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.952082 | 312 | 3.1875 | 3 |
WHY BE A PART OF
Insurance is one of India’s sunrise sector
Insurance Penetration in India is currently around 3.7% as on FY 20. This is low in comparison to the penetration recorded in comparable Asian economies such as Malaysia, Thailand and China which are at 4.72, 4.99 and 4.30 % respectively. This presents a huge opportunity for growth in the Insurance sector. Several initiatives are being taken up by the government to fuel the growth in the form of Health schemes. A recent initiative is the announcement in the union budget FY21 to increasing the FDI in Insurance from 49% to 74%. Needless to say that exhaustiveness of Insurance distribution would be critical in taking the reach of Insurance to the undeserved.
Motor Insurance is a need ( Motor Third Party is compulsory), Market share for Motor Insurance is approx. 35% in FY21. India is the largest manufacturer of 2W and 3W and the 4th largest manufacturers of passenger cars in the world.
There is an increased awareness about Health and Life Insurance. Retail health Insurance has shown a sharp growth trend in FY21 of approximately 21.8%. Indian life insurance industry capped FY21 with a 7.5% increase in new business premiums (NBP).
Assisted Distribution models have been contributing a major share of the total insurance premium in India. | <urn:uuid:8ea0c3a5-9fc8-4522-a070-7ada5fbfcb0e> | CC-MAIN-2022-33 | https://sarathiaapka.com/why-insurance.php | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.952705 | 286 | 1.53125 | 2 |
Surrounded by lush greenery, colourful flowers and amazing animals from around the world, the San Diego Zoo has much to offer. When visiting the San Diego Zoo, to see as much as possible, I recommend starting early as my day started at opening (9:00am) and I was there for eight hours. Now come with me as I take you part way around the San Diego Zoo from the Northern Frontier to the Outback and from the largest bears to the tiny dung beetle.
After a ride on the guided tour bus that takes you around three-quarters of the zoo I took the awesome aerial ride, Skyfari, from one side of the zoo to the far reaches of it, offering fantastic views of the zoo and Balboa Park. At the far side of the zoo I was deposited at the Northern Frontier, home to Polar Bear Plunge, a 130,000 US gallon pool, and the zoo’s polar bears. On my visit the polar bears were enjoying playing with an enrichment log full of tasty carrots. The Northern Frontier is also home to caribou, artic fox and an Arctic aviary. A stroll through the awesome Arctic aviary is wonderful, home to over 25 species of duck, these are some of the most beautiful ducks I’ve ever seen. From buffleheads to mergansers and smews to harlequins, I saw much beauty and even a bunch of baby ducklings.
After the chill of the Arctic I headed down through Elephant Odyssey and Africa Rocks. At the northern entrance there is a great educational exhibit called Fossil Portal that is set up like a mock excavation site, a simulated tar pit, that reveals bones from animals that once roamed South California around 12,000 years ago. You’ll also see life-sized statues of the Colombian Mammoth, the Saber tooth cat and more, beside their modern-day counterparts. It’s here I met and saw some amazing animals doing amazing things, like watching a keeper working on training a female lion, she knew exactly what to do to get her reward (a chunk of meat.) I was also entertained by the stoic – yet comical – secretary bird, with its proper posture and long, skinny legs. I stood and watched as this bird, whose natural diet includes lizards, used a small stick to display its natural behaviour in killing its prey by taking the lizard (or stick) and throwing it down to the ground, stomping on it and repeating the process. It was amazing to watch. I also met Delilah, a black hornbill who I learned likes people so much so that they had to put up a plastic sheet around her wired enclosure fence because she kept bringing her visitors dead mice. Ah, so thoughtful.
Get your cameras ready for all kinds of cute, like the stocky capybaras with their large sandy beach to lounge on and large pool of water to take a refreshing dip in, plus they even had a few darling babies. Another great enclosure full of cuteness was the meerkat one, they were mostly all playing or digging but I also loved that the enclosure was full of tunnels, natural vegetation, rock and a large simulated termite mound – great for the sentinel meerkat to perch atop and be on the lookout.
From the cute to the not so pretty, there are also the zoo’s California condor’s here, still endangered the California condor is making great progress thanks in part to dedicated conservationists and scientists in the field as well as great West Coast zoos like the San Diego Zoo. Though they have an ugly name dung beetles are a vital part of the ecosystem as they are the original recyclers. Dung beetles are truly incredible, feeding on dung or feces, they can roll a ball of dung up to 10 times their own weight and they are the only insect known to orient themselves by the galaxy – now that’s out of this world!
The main feature is Elephant Odyssey’s elephant habitat covering 2.5 acres and home to the zoo’s blended herd of three African and four Asian elephants. The well drawn out habitat offers several pools, one being 4,600 square feet and 7.5 feet deep at it’s deepest, as well as the Elephant Care Center where you can watch keepers do husbandry training and routine care with the elephants. During my visit I watched on as one got a pedicure – might sound indulgent but it’s actually vital health care for theses large mammals.
My next stop was the Outback, home to some of the strangest and coolest animals on Earth like echidnas, one of only two mammal species that lay eggs, the other a fellow Aussie is the duck-billed platypus. The zoo’s Outback is also home to wombats, wallabies and the Tasmanian devil, with its powerful jaws that create 1200 psi (pounds per square inch) – compare that to a human’s 265 psi. The San Diego Zoo is actually one of only two zoos in the Untied States to have these remarkable creatures. The Outback also has some interesting birds like the loud, laughing kookaburra and the bowerbird. The male bowerbird is not brightly coloured and showy like some other male birds but he’s clever and a star decorator, he builds elaborate structures called bowers to attract females and decorates his bower with colourful things he finds, namely garbage, like blue plastic or yellow string for instance; he may not be attractive but he knows what is.
The newest part of the Outback is Koalafornia, finished in 2013 and home to the largest number of koalas outside of Australia. In 1997 the San Diego Zoo welcomed the first albino koala to be born in a zoo and named him Onya-Birri (“ghost boy” in Australian Aboriginal language). I was astounded by all the koalas, many dozing in trees like they often are, but with so many chances are good to actually see some activity however slow and mild it may be. I was excited to see a few climbing around on the elaborate tree structures and even witnessed my first koala yawn – I must admit it was the cutest and funniest thing ever!
So whether your favourite animals are polar bears or koalas the San Diego’s Northern Frontier to the Outback exhibits are chalked full of interesting, loveable and truly cool creatures! | <urn:uuid:cddc1b22-ea7f-4777-8702-3525d6783df4> | CC-MAIN-2022-33 | https://ladyofthezoos.com/2014/06/15/northern-frontier-trails-to-the-outback/?shared=email&msg=fail | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.969118 | 1,346 | 1.742188 | 2 |
Here is a step by step guide on how to use the Image Trace panel in Adobe Illustrator. There are completely different views you possibly can see the vector pathing as well – for instance we will see the tracing result by default. Now the paths slider will control how carefully the picture tracer will replicate the unique picture.
The image can now be exported after which imported into Illustrator. Let’s get started with a demonstration on how to trace a picture to vector with Illustrator in a easy monotone, or black and white, format. First select the picture then select image hint within the instruments choice bar. So now you know the way to trace an image in Illustrator, however tracing photographs is just one of the many issues that you are able to do. After all, it’s called Adobe Illustrator, not Adobe Tracer, proper?
Illustrator Tutorial: Tracing Images In Illustrator Cc
There is nobody-size-suits-all, you always want to find out what’s suited best in your kind of picture. To trace your image in color somewhat than black and white, make sure to decide on the Auto-Color setting at the top of the menu. Then click on Preview to see how your tracing will look.
Once you’ve received the picture saved to your pc, open up Adobe Illustrator and create a brand new document. It doesn’t matter what dimension you select for the preliminary artboard—I just went for A4 panorama. We need a black and white drawing, however it can be as elaborate and complex as you want.
How To Digitize Hand Lettering Using Illustrators Image Trace
Again, this all depends on your distinctive image – so it’s best to find a joyful medium. Next, modify the Colors, Grays, or Threshold slider. This slider will change relying on the mode you select, however the performance between the 3 sliders stays comparable.
On the opposite hand, a vector is comprised of paths. These are mathematically calculated graphics which do not close clarity as they broaden. Think of it like shapes that come together to type a graphic, and as an alternative of the pixels growing, the paths merely broaden in dimension. Firstly, let’s go through the differences between Raster and Vector, since we’ll basically be changing from one to the other. | <urn:uuid:c91a4a75-de03-40e5-8f74-2ec2ae30799e> | CC-MAIN-2022-33 | http://gsmhani.com/2021/05/01/illustrator-tutorial/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.917714 | 502 | 2.25 | 2 |
A belated Eid Mubarak to everyone! Ramadan was officially over at about midnight on July 27, and Eid Al Fitr (the feast of the breaking of the fast) started on July 28. The celebrations for Eid typically last for three days, so for three days there were feasts, festivities and fireworks. Gifts were exchanged, usually in the form of Riyals (cash), new clothes were bought and worn, the poor received an abundance of money, gifts and food, and the Malls were emptier. Many of the stores in the Mall were closed, but not most of them, as is usually the case on Christmas in the west. For those that were open, they were offering huge discounts – 50-70% off – which is a lot like the first few days after Christmas.
On Eid, I even got a couple of gifts from my employer, which happily surprised me. And a few times, I received gifts of food from strangers while out and about. The spirit of giving and a time for that giving seems to exist all over the world.
Because of the Eid holiday, I have been at home for the past five days. I have done mostly a lot of nothing, which we should all do occasionally. Some of the teachers left the country “on holiday” and some, like me, stayed and enjoyed the calmly festive environment of Riyadh. But, back to work on Sunday!
I hope that everyone had a joyful and blessed Eid. | <urn:uuid:afd704a7-da77-462e-a08e-f91d823d39ae> | CC-MAIN-2022-33 | https://littlewritersway.com/2014/07/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.992066 | 298 | 1.578125 | 2 |
This course introduces students to the use of dental related software. The information and techniques will be applied to the design and creation of patterns for basic dental restorations from various restorative dental materials. Students will also use the dental software to learn and practice tooth anatomy and morphology.
Course code: DENT 1180
Length: 90.0 hours
* Fees are approximate and subject to change. Students are required to pay any applicable fee increases. Fees listed are for domestic students. For international programs, visit VCC International.
† This information is intended as a guideline only. Program and course details are subject to change with the approval of VCC's Board of Governors. | <urn:uuid:a9811bb7-3234-4a23-b6f5-6936e8d8813b> | CC-MAIN-2022-33 | https://www.vcc.ca:443/courses/dent-1180/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571869.23/warc/CC-MAIN-20220813021048-20220813051048-00065.warc.gz | en | 0.905374 | 175 | 1.53125 | 2 |
7/24: THOUSANDS TO OCCUPY D.C. DURING INTERNATIONAL AIDS CONFERENCE, CONVERGING ON WHITE HOUSE TO DEMAND AN END TO THE AIDS EPIDEMIC
AIDS Foundation of Chicago is helping to facilitate march of more than 30,000 -- DC residents, US activists from across the country & global delegates alike calling for the resources, rights and policies to end AIDS
Washington, DC: In a time in which science has shown the path to end the AIDS epidemic, and the Occupy movement has spotlighted the inequitable use of resources that constrain these and other efforts, more than 30,000 people living with HIV and other AIDS activists from hundreds of organizations worldwide will join to demand rights and resources to cure HIV/AIDS.
The mobilization, entitled We Can End AIDS, will begin Tuesday, July 24, 2012 at 12 p.m. as five distinct branches flood downtown Washington with a range of creative and powerful actions. The marches, scheduled to occur during the International AIDS Conference, will snake through the streets of the District, including K Street, New York Avenue and Pennsylvania Avenue, meeting Lafayette Park at 1 pm to deliver a powerful collective message to the White House and the world: To end the AIDS pandemic, we demand the political will necessary to ensure economic justice for all and to defend and protect the human rights of our marginalized communities, including people living with HIV & AIDS.
We already know that the big story of the conference is that we could end the epidemic as we know it, said Julie Davids, of the HIV Prevention Justice Alliance, one of the coordinators of the Human Rights and Harm Reduction branch of the mobilization.
But will we? said Davids, who is also director of national advocacy and mobilization for the AIDS Foundation of Chicago. These marches draw together the necessary elements of what it will take to reap the benefits of new research pointing the way towards the end resources, political will, and an end to discrimination and criminalization.
We Can End AIDS was created to draw attention to evidence showing that, with only modest increases in funding and appropriate policies, the world could see the end of the AIDS pandemic within 30 years. We Can End AIDS is demanding the economic justice and human rights to make this a reality.
Bolstered by HPTN 052, the study that proved treatment is an effective form of HIV prevention, and which indicated that widespread treatment could thus end the epidemic in a generation, each of the five branches of the mobilization represent what is needed to achieve this outcome:
Demand an end to pharmaceutical greed
Demand a Robin Hood Tax on Wall Street to end AIDS
Stop the war on women
Demand sound public policies and full funding
Protect human rights: end mass imprisonment and criminalization, and support harm reduction.
The International AIDS Conference will be held in Washington, DC from July 22-28th in Washington DC, a city with HIV rates higher than 32 African countries.
Follow: #endAIDS, www.wecanendaids.org | <urn:uuid:8170a0a8-fd80-46a3-b729-aeeedc1fc408> | CC-MAIN-2022-33 | https://www.aidschicago.org/page/news/all-news/thousands-to-march-for-hiv-justice-next-week-in-dc | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.93191 | 623 | 1.585938 | 2 |
Mindful Self-Compassion (MSC) is an 8-week, training program, based on the groundbreaking research of Kristin Neff and the clinical expertise of Chris Germer. It is designed to cultivate the skill of self-compassion.
Rapidly expanding research demonstrates that self-compassion is strongly associated with emotional wellbeing, less anxiety and depression and reduced stress levels. It can support the maintenance of healthy habits such as diet and exercise and has been shown to lead to greater resilience and strength.
People are welcome with or without previous meditation experience
The course will be facilitated by Julia Sweetman, Certified MSC teacher and Nutritional Therapist and Orla Burchael, MSC teacher, Clinical Psychologist and Mindfulness Based Stress Reduction teacher.
Join us on our Mindful Self Compassion (MSC) training programme where we explore self-care, self-kindness and learn the tools of mindful self-compassion. | <urn:uuid:0cc0e6bf-3baa-44aa-b752-2ea531b98480> | CC-MAIN-2022-33 | https://centerformsc.org/course/8-week-mindful-self-compassion-course-448/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.946177 | 194 | 1.78125 | 2 |
Discussing the future of humankind in the pandemic/post-pandemic scenario has become a common practice around the world. DESIS Network brought this discussion to the Design table during an international webinar with professors, students and researches from many parts of the globe. Almost 100 people joined the webinar, which was done via Zoom and also streamed through our YouTube channel.
The proposal was to rethink the contributions made for Conversations 2020, this time under the circumstances of Covid-19 crisis, and moving on towards a DESIS Manifesto, which will reinforce our commitment to social innovation and sustainability as pillars of DESIS design practices.
The event started with a recap of Ezio Manzini’s contribution, “Social Innovation for the Planet”. Manzini, who is the DESIS Founder, brought to the spotlight the following question: how could we recognize the social innovation practices toward the environmental issue, considering the importance of locating these activities in our territories around the world?
From that initial question, DESIS members from South Korea, Portugal, Italy, New Zealand, China, Ghana, Canada, Greece, Brazil and Denmark made equally remarkable contributions. Two of the reflections were especially interesting: the first, about the value of including non-humans/more than humans interactions in the Design practice researches and studies; and the other one concerning multi-cultural approaches to Design, such as the Chinese philosophy, that considers the unity about humans and the universe as the basis of an ecological civilization.
To summarize the presentations, the participants worked together in a collaborative whiteboard containing the key-words of their Design practices, interests and projects. Some of the words were: a community of place, thinking radical, multi-species inclusivity, transformational change and regeneration.
The second round of discussions should take place later this year, to reunite the reflections about Design, the “new normality”, the environmental concerns and all topics mentioned during the webinar. In this opportunity, a DESIS Manifesto would be presented, written by DESIS members and partners eager to contribute on this matter.
If you missed this webinar, you can watch it anytime on our YouTube Channel and also subscribe to our Newsletter – so you will never miss a DESIS event again! You can also check the DESIS Repository about projects related to the Covid-19 pandemic and, if you’re interested, click here to read more about the Conversations 2020 initiative. | <urn:uuid:ede0706a-e316-4a91-8c4a-d03f77a8e785> | CC-MAIN-2022-33 | https://www.desisnetwork.org/2020/07/18/desis-network-event-highlights-new-approaches-of-design-for-the-future/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.941646 | 507 | 1.976563 | 2 |
The East Texas "winter" is officially a week old and we are still consistently above 80 degrees during the day. If the days weren't so short I would swear it was April. Even some of my dormant mulberry saplings are starting to leaf out. Rather than worry about what that might do to baby trees I am taking the time to do something new this winter. I'm composting with gusto.
"Necessity is the mother of invention" I am told, and I might have never considered compost as a heat source unless I was limited to 15 amps and an antique wood stove for heating my greenhouse project this winter. It is not possible for me to generate more than 5,200 btus with the power I have available and the stove requires almost constant supervision. Texas weather likes to lull us to sleep with warm days & mild evenings until one mid-January or mid-february day we wake up to -6 Fahrenheit and everything I planted dies. (Not this year, I hope.)
I have composted the lazy way for years. I would just pile junk up all year in a shady spot and then turn it over in the Spring to harvest the good stuff found near the bottom of the pile. That isn't really composting "intentionally". Internet research led me to several youtube videos of other garden addicts using piles of kitchen scraps, leaves, and grass clippings as a steady and reliable source of "free" heat INSIDE their greenhouses. The ingenious folks in these videos were taking advantage of the fact that compost generates its own heat - as microbes & critters decompose the organic material in the pile. These piles are capable of reaching core temperatures up to 160 degrees and some sources claimed that 1 cubic yard of compost can generate 1,000 btus/hour, 24 hours a day, for up to 6 months! That's a whole lot of heat that doesn't send a monthly bill!
So, I've decided to repurpose the area planned as my future worm bin and use it this winter as a compost heater for the greenhouse. The concept I settled on is a hybrid of three different solutions used successfully by other gardeners. It was such an epiphany that I had to share it here. Feel free to take this idea and improve it any way you can for your own benefit.
(That is one of the best perks of garden clubs.)
Basically, water is the material that transfers the heat at the core of the compost pile and allows it to be used to heat the air. I am using a 55 gallon drum (painted black) to store the water. A submersible pump is used to move the water from the bottom of the storage tank where it is coldest, through a plastic tube coiled inside the compost pile. This tubing makes multiple passes through the depth of the pile so that it remains inside the warm core as long as possible absorbing heat. After looping through the compost it is pumped through a small, aluminum, radiator coil (designed for cooling transmission fluids) where it pre-heats the air entering a small space heater/fan. If the incoming air is warm enough then the thermostat will not engage the heating element. If the incoming air is too cold, then the t-stat will turn the heater on. Either way, the fan runs automatically, keeping the air moving and the potential for fungus down.
The full system will not be operational until this Thursday evening when the radiator I ordered finally arrives. But I have had the compost pile prepared for a week now and it is already generating heat I can feel on the surface. The water inside the black drum is consistently 5 degrees warmer than the soil it sits on due to heat gained from the sun during the day. When the sun does not shine, the water inside the barrel will act as a heat sink for the compost pile and release the warmth slowly into the area all night long. I am excited to learn how well this system works!
One of the key ingredients I have learned must be included in your "intentional" composting effort is a proper compost thermometer. The temperature of the pile is a critical metric that you should be aware of in order to work out the timing and management of the compost. They are inexpensive and I purchased mine on Amazon. In fact, the manufacturer included a handy PDF that describes how to properly manage a compost pile. I have attached that document to this post for you to download for free, if you like.
I plan to follow up in future weeks to let you know how this experiment ultimately works out, but initially, I am very pleased. Five-six months from now the weather will be warmer, a new season of plants will be "Springing", and I will have another 1.5 cubic yards of fresh compost for the garden.
Win, Win, Win!
Thanks for reading! | <urn:uuid:dd4a5575-1659-4235-a5bd-98a7c8ee5678> | CC-MAIN-2022-33 | https://www.grumpysgardenclub.com/post/piling-it-on | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.957626 | 998 | 1.882813 | 2 |
Root canal treatment involves removing the nerves and blood vessels that supply the tooth.
Root canal treatment is carried out to save the tooth and prevent the spread of infection. The procedure involves removing the damaged pulp from the tooth and the root canal is then cleaned of all bacteria.
After the bacteria have been removed, the root canal and pulp will be filled up using an artificial substance, before being sealed.
Implants, on the other hand, are specially made posts that replace the roots of teeth that are missing and are used to support a new crown, fixed bridge or denture. It is made of titanium, a strong and lightweight material which has been shown to be compatible with the body and safe for use.
RCT involves removing the nerves and blood vessels that supply the tooth. It is needed when the nerve of the tooth (known as the pulp) is infected & dies because of decay or trauma from accident / fall.
RCT is a skilled and time-consuming procedure. This may require two or more visits to your dentist. The aim of the treatment is to remove as much infection from the root canal as possible. A good amount of local anesthetic is administered to numb the tooth.
Root canal treatment may require 2 or more visits to the dentist as it has to be performed meticulously.
Some X-rays will have to be taken during the procedures. The tooth is isolated with a rubber dam and a clamp on the tooth.
The dentist will administer an injection (local anaesthetic) to the area around the tooth. You will feel a bit “fat” at the cheeks when you are numb. The dentist will drill and remove all decay present, and make an opening into the pulp chamber. Next, using a very fine instrument known as a file, the infected nerve is located and removed. The canal is rinsed and medication is placed inside the root canal to kill bacteria. A temporary filling is placed to prevent the canals from being damaged by saliva.
During the next visit, local anaesthetic will be administered again to numb the tooth. The temporary filling is removed. Progressively thicker files are used to clean and shape the entire length of the root canal. Medication is placed within the root again and a temporary filling is placed.
Depending on the number of canals and complexity of the case, this procedure may be repeated again on another visit. Finally, the root canal is rinsed, dried and filled with a rubber material within the root. A filling is placed on top.
This is a fee estimate & subject to change. Please check with your clinician for an exact fee based on your unique clinical condition. | <urn:uuid:e6de852f-6871-403a-8b44-ecdafc2d870a> | CC-MAIN-2022-33 | https://www.dentalplus.com.sg/root-canal-treatment/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.947029 | 563 | 3.296875 | 3 |
Your entire life is an indication of the ideas that take place in your head.
This is a quote made famous by Australian television manufacturer as well as author Rhonda Byrne, that published her very popular self-help publication The Secret in 2006. Guide went on to offer greater than 30 million duplicates, get a myriad of celeb fans including Oprah Winfrey, Will Smith as well as Ellen DeGeneres, and also form the bedrock of symptom practices seen around the world today How To Write A Manifesto Poem.
But materializing, which is basically prepared your goals right into presence, isn’t exactly a new sensation. Based on the Law of Attraction, which was part of the New Thought movement as well as theorised by 19th century spiritualist Phineas Quimby, manifesting is everything about the idea that our thoughts are energy.
The concept has its foundations in several philosophical and religious customs, from Hermeticism and also Transcendentalism to Hinduism, and has been increased on by several Twentieth Century philosophers such as Napolean Hill (Believe and also Grow Rich, 1937) and Louise Hay (You Can Recover Your Life, 1984). To place it just, showing up aims to place the individual in the motorist’s seat of their very own life and also makes them in charge of the favorable and also negative impacts in their lives.
What Is manifesting?
In contrast to the belief that ‘seeing is thinking’, materializing is everything about believing in something in order to see it come your method. ‘Materializing is the capacity to utilize the power of your mind to alter as well as create the truth you experience,’ explains self-development instructor Roxie Nafousi.
Nafousi started materializing at the age of 27 after suffering from an enhancement to drug, alcohol as well as cigarettes for several years, and really feeling a lack of self-respect and also function. Feeling something ‘click’ in her mind after listening to a podcast on manifesting, the mother-of-one has actually since carved out a name for herself in the health market, as well as recently became a Sunday Times bestselling author complying with the publication of her publication Manifest: 7 Steps to Living Your Ideal Life.
‘ [Manifesting] is a method that benefits actually every location of your life due to the fact that it empowers you to come to be the greatest variation of on your own that exists, embody the individual you most wish to become, as well as assist you to unlock the limitless capacity that you have to develop the life of your dreams,’ she continues.
What are the actions for manifesting?
The idea of starting on your showing up journey might have you wishing to compete capitals, especially if you’re not made use of to taking time out to rest with your ideas. As opposed to quickly investing a ton of money on bullet journals, expensive looking really felt pointer pens or panicking at the view of a yoga floor covering, Nafousi says showing up begins with a private getting clarity on how they really desire their life to look, and exactly how they intend to feel in 6 months or a year from currently.
For some, this could be accomplished by developing a vision board you ‘d see in a meeting area filled with key phrases, timelines and also pictures. For others, it may involve visualization reflection.
1. Understand what you want to manifest
‘ Be crystal clear regarding what it is that you wish to manifest as well as be as outlined as possible. If you want to manifest more money for instance, be specific – how much money, by when do you intend to acquire this quantity, how does it really feel to have this abundance of cash in your life, what would you finish with the cash?
On a notepad, jot down just what it is that you want as well as imagine how you ‘d really feel if you reached your goals. Allow your emotions cut loose as well as write them all down.
2. Work on your attitude
Try to overcome your limiting ideas and ensure your mindset is in positioning with your goals If you want something, yet deep down you do not believe you’re worthy of it, you will push that objective better away.
3. Take heartfelt activity towards your goals.
Put in whatever work you can from your side to relocate you better towards your goal, and leave the remainder to deep space.
The professionals suggest making workable goals that are realistic to satisfy and accomplish, whether it’s taking place a daily stroll to inevitably reach your 10km run objective, or reaching out to prospective companies through e-mail if you wish to transform jobs by the end of the year.
4. Technique gratitude
Be grateful wherefore you already have and thankful for what other attractive blessings are ahead.
Stuart Sandeman, founder of Breathpod and host of BBC Radio 1’s Decompression Sessions claims that gratefulness ‘will assist change your mind-set from “absence” to “wealth”, which means you’ll choose to concentrate your energy on whatever you have in contrast to what you do not’.
5. Elevate your vibration
Some of the methods I recommend which help to raise my resonance are yoga exercise, reflection, exercise, a plant-based diet regimen, surrounding myself with positive and also motivating people, resting as well as waking early with eight hours of sleep, paying attention to self-development podcasts, journaling as well as exercising gratefulness.
Review ELLE UK’s checklist of the very best podcasts for 2022 below.
6. Be open as well as receptive
Energy streams, where attention goes. Offer loving power to whatever remains in line with your goals. As soon as you remain in this state of flow, you will start to bring in more of the right people and also scenarios to assist you fulfill your goals. And also in the due training course of time, you will find yourself walking through doors you when prayed would certainly open up.
When as well as how should you manifest?
From getting a Deliveroo to your door in under as well as hr, or choosing the specific checkout at Sainsbury’s, we’re all guilty of desiring prompt gratification in today’s tech-driven world. Yet, in similar manner in which treatment and also exercise can not create overnight outcomes, showing up is a slow-burning practice that requires commitment and perseverance.
Manifesting benefits actually every location of your life
To begin, Sandeman suggests those interested in manifestation begin their day with a specialized breathwork, visualisation as well as thankfulness technique in the early morning, and also finish their day by creating a vision board to help intensify the process. You can have a look at Sandeman’s day-to-day breathwork manifestation techniques right here.
What are the greatest misunderstandings as well as problems bordering manifesting
One of the largest issues bordering showing up is people thinking that it’s an easy process ‘or that imagining one’s desires suffices’ to see change, says Nafousi. For example, by frequently telling the universe you want a brand-new auto, you’re not incredibly mosting likely to discover a glossy Ferrari on your driveway without doing some sensible job to accomplish that objective. ‘There is no replacement for effort!’ she adds.
Contrary to popular belief, positive thinking alone isn’t mosting likely to produce alter either. While some researches have actually found those with a favorable attitude are most likely to accomplish their aspirations, Fatmata Kamara, a mental health and wellness registered nurse consultant at Bupa UK suggests that success is influenced by the behaviour adopted from a positive state of mind, instead of manifesting alone. ‘Previous study has likewise located the capability to think of events prior to they occur can help with choice making procedure, meaning the choice maker has the ability to eliminate choices which would be much less effective,’ she claims. | <urn:uuid:10757f2c-5c02-4333-b1c7-8b1c2cb62e59> | CC-MAIN-2022-33 | https://www.act-one.org/how-to-write-a-manifesto-poem/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.96836 | 1,673 | 1.851563 | 2 |
Google indexes website content on various kinds of storages. These storages are totally based on how those pages are likely to search for. Gary Illyes of Google discloses that the search index uses a tiered system. In this system, the most demanded content is indexed on faster and on more valuable storage.
Types of Storage
While telling how Google constructs its search index, Illyes of Google there are types of storage on which the content is indexed which are as follows:
- RAM (Random Access Memory): Fastest and most expensive
- SSD (Solid State Drive): Very fast but cost-prohibitive
- HDD (Hard Disk Drive): Slowest and least costly
Further, he added that Google always keeps the reserve of RAM for the documents that are going to search on a daily basis over the search engine.
And then, when we build our index, and we use all those signals that we have. Let’s pick one, say, page rank, then we try to estimate how much we would serve those documents that we indexed.
So will it be like every second? Will we have a query that triggers those docs? Or will it be once a week or will it be once a year?And based on that, we might use different kinds of storage to build the index.
Garry Illyes gives a couple of examples as well on what things are to be stored on those three different storage types. RAM or SSDs are used only for the content that is asked on every single second over the search engine.
So for example, for documents that we know might be surfaced every second, for example, they will end up on something super fast. And the super-fast would be the RAM. As part of our serving index is on RAM.
Then we’ll have another tier, for example, for solid-state drives because they are fast and not as expensive as RAM. But still not– the bulk of the index wouldn’t be on that.
The bulk of the index would be on something that’s cheap, accessible, easily replaceable, and doesn’t break the bank. And that would be hard drives or floppy disks.
This topic was discussed in the last episode of Google’s Search Off the Record podcast. The podcast only deals with language difficulties in the search engines while doing indexing. This is considered to be the first time when Google reveals some information on its search storage tiers.
Well, it is hard to say that what storage type will Google use to index your website. Therefore. SEO has no choice to optimize their content for a particular storage type. | <urn:uuid:2c2241a8-eea9-4583-abb4-523592af6859> | CC-MAIN-2022-33 | https://technians.com/news/google-operates-with-faster-storage-spaces-for-highly-request-pages/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.934778 | 549 | 2.46875 | 2 |
Rearview cameras are becoming a fundamental safety feature for vehicles; in fact, the National Highway Safety Transportation Agency (NHTSA) announced that all cars built after May 2018 must have rear-visibility technology. So in this post, I will discuss the benefits of using low-dropout regulators (LDOs) to handle the power constraints of rearview cameras. Figure 1 shows common features of performance LDOs.
Figure 1: LP5907 and LP5907-Q1 Features
If you are designing a power supply for automobile cameras, your main concerns are clean voltage regulation and optimized total system size and cost. These requirements can be achieved using LDOs as shown in the TIDA-00535 reference design; TIDA-00535 provides guidelines, test data and design files of a power management solution at the camera module side. Figure 2 shows a conceptual block diagram of TIDA-00535.
Figure 2: TIDA-00535 block diagram
Clean voltage regulation means low ripple and steady voltage regulation, both crucial for the Complementary Metal Oxide Semiconductor (CMOS) image sensor inside the camera module. The CMOS image sensor is sensitive to variations in the nominal input-voltage level. Voltage ripple and voltage undershoot and overshoot transients disturb the functionality of the active amplifier and photodetector element inside of the sensor, therefore the ability of the CMOS image sensor to capture incident light intensity is compromised, this means that the image quality will be affected presenting dots or dark lines across the image. With high power-supply ripple rejection (PSRR), low noise and great transient-response characteristics, LDOs are capable of minimizing the ripple voltage from a switching regulator or coupled interference in long PCB traces.
Image sensors require various voltage rails. One rail is usually between 2.8V and 3.3V, while the other rail requires lower voltages typically from 1.2V to 1.8V. The low-voltage rails are more sensitive to power-supply ripple; therefore high-PSRR LDOs are preferable. The LP5907-Q1 offers high-ripple rejection as shown in Figure 3.
Figure 3: LP5907-Q1 frequency vs. PSRR graph
TIDA-00535 uses the LM43602-Q1 a switching-mode regulator to generate 3.3V from the power-over-coaxial source. The 3.3V voltage is further regulated using two LP5907-Q1 LDOs to generate 1.5 V and 1.8 V voltage rail. The LM43602-Q1 switches at a frequency of 500 KHz its output ripple is almost non-existing at the output of the LDOs thanks to the ~45 dB PSRR at 500 KHz. Figure 4 shows the ripple rejection capability of the LP5907-Q1 in an extreme case in which the LP5907-Q1 input voltage has a ripple of 50mVp-p at a frequency of 3 MHz.
Figure 4: Comparison between Input voltage ripple and LP5907 regulated output
Cameras should not affect the cosmetic design of the automobile; in other words, they should be small and somewhat concealed. Since camera modules have size constraints, a common practice is to transfer power and data between the engine control unit (ECU) and camera module with a coaxial cable or differential pair, minimizing the number of cables and components needed at the camera module location. LDOs help achieve total-solution-size and system cost requirements because they only need a few compensation components. For example, the LP5907-Q1 only needs a small input and output ceramic capacitor for stability, in contrary to switching regulators that requires capacitors, inductors and resistors increasing the total BOM cost and system size. In addition LP5907-Q1 is available in the Small Outline Transistor (SOT-23) package (2.90 mm by 1.60 mm) for automotive grade devices that needs to meet the Automotive Grade Council standards (AEC-Q100) and for non AEC-Q100 grade applications the LP5907 is available in smaller packages the Die-Sized Ball Grid Array (DSBGA) package which is only 0.675 mm by 0.675 mm (Max) and the Small Outline No-leads (X2SON) package 1.00 mm x 1.00 mm (NOM).
Efficiency might be another system concern. The system will only operate a few seconds at a time and most of the time it will be powered off by a relay at the ECU side, for these reasons the efficiency of the LDOs can be justify with its low noise and high PSRR performance.
To summarize, LDOs can greately contribute to automobile camera’s power management by providing a high PSRR and low noise output while mantaining a small total solution size at an optimized BOM cost.
To get started review the Power Management Solution for Automotive CMOS Imager and Data Serializer Reference Design which provides a detail design guide, schematics, Gerber files and a bill of materials for the power section of a camera module.
- Small Size, low noise and High PSRR Power Reference Design for CMOS Image Sensors
- View rear camera reference designs and solutions.
- Download the “Advanced Driver Assistance (ADAS) Solutions Guide” and “Automotive and Transportation Solutions Guide.”
- Read another blog about power supply design considerations for advanced driver assistance systems. | <urn:uuid:143bd94b-bcc9-4707-afb9-04d800ba05ce> | CC-MAIN-2022-33 | https://e2e.ti.com/blogs_/b/powerhouse/posts/benefits-of-using-ldos-to-power-automobile-camera-modules | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.870807 | 1,146 | 2.25 | 2 |
Robert Jelinek / Christoph Steinegger - Sabotage – Torments & Vices
Founded in Vienna back in 1992 under the guidance of artist Robert Jelinek, Sabotage Communications celebrated their 10th anniversary with this book in 2002. Sabotage does not mean destroying economical or political goods, but to disturb and manipulate human activities and incite reaction. These ideas are developed out of observations and studies on behaviour. Many ideas are developed through dialogue with scientists, physicians, researchers and shamans some of whom stay in contact with certain projects for many years. For the first time since their inception all local and international activities will be brought together and published by Sabotage’s head of design Christoph Steinegger in this magazine slash book. | <urn:uuid:8c1b9520-4162-4cbb-a4ba-68ed0b66c289> | CC-MAIN-2022-33 | https://underbelly.nu/product/sabotage-torments-vices/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.931727 | 160 | 1.515625 | 2 |
Compact in size and with a signature shuffle, the English bulldog possesses renowned and highly recognizable features. Despite their slightly disgruntled facial expression, English bulldogs are amiable and very loyal pets. Contrary to popular belief, English bulldogs can be quiet, tentative, and observant.
English bulldogs are smart and intelligent dogs. They convey strong emotional intelligence and are not only astute and sensitive to their surroundings, but they are also exceptionally protective of their owners.
How smart are English bulldogs compared to other breeds?
In comparison, according to many studies and psychologist Dr. Stanley Coren, the Border Collie is ranked as one of the most intelligent dogs: its frisky and highly-alert nature make them ideal for fulfilling their purpose of herding sheep and working alongside farmers. They demonstrate speed and energy, their tactical minds and ability to problem-solve make them reliable yet independent.
English bulldogs are not necessarily blessed with the gift of swift-thinking and problem-solving nor are they always adept at thinking on their feet, yet owners can rest assured that their bulldog will sense any problem and be ready to faithfully guard their owner! Their loyalty and alert nature leads them to recognize if their owner, children, or anyone else around is at risk.
How are dogs’ intelligence measured?
There are several breeds that most of us associate with as being smart, working dogs. German Shepherds are known for their protective instincts and for working alongside the police force whilst the Cavalier King Charles Spaniel is an excellent therapy dog with its empathetic and soothing temperament. And Golden Retrievers are relied on for guiding and even rescuing vulnerable owners. Different breeds have different skill sets, and its good to understand what activities they are best suited for and what types of owners they will match best with.
There are two primary ways of measuring a dog’s intelligence: ‘instinctive intelligence’ and ‘adaptive intelligence’. ‘Instinctive intelligence’ takes into consideration the reasoning behind what the dog was bred for and how well it adheres to this purpose. Initially, over one hundred years ago, bulldogs were bred for bull baiting and were identified as strong aggressors, but after being crossed with a Pug, their predominantly aggressive streak was complimented by their more affectionate side.
‘Adaptive intelligence’ is a measurement of a dog’s ability to think and act independently and how they are able to approach a range of tasks and problems. If we look at Border Collies again, a farmer needs a dog that is motivated and tactical so that it can fulfill its duties on the farm and out on the fields. With an ability to firmly lock eye contact and make decisive decisions, the way in which this breed of dog performs out on the field demonstrates its fastidious mind. Although these qualities are ideal for certain owners and purposes, the breed needs to be consistently challenged and given healthy outlets. If you are seeking a calm home-life and leisurely dog walks, you might want to consider a non-working breed.
English bulldogs are proven to have an innate tendency to protect and even offer compassion and empathy to owners when they are grieving. These are valuable qualities in a pet—especially within a family unit or around children. Their ability to make those around them smile, not only because of their unique appearance but also their general funny demeanor, means that they make exceptional playmates for little ones and brighten up the entire family’s day!
An important point to remember is that although bulldogs can be entertaining and exhibit high bursts of energy, they are predominantly indoor dogs and are not designed to spend lengthy amounts of time outdoors unsupervised nor are they the type of pet that you would choose to go running with or on a long walk.
How can you administer a dog IQ test at home?
There are numerous tests and tricks to establish a dog’s intelligence. According to Dr Cohen’s test, which will allow the owner to consider elements of its dog’s ‘adaptive intelligence’, one way of recognizing a dog’s ability to problem-solve is the basic test of putting a blanket over the dog’s head and waiting to see how long it will take for the dog to get out from under it. This easy test is a great starting point to determine a dog’s ability to problem-solve and their ability to self-motivate; plus. it is a quick, easy and fun task that can be carried out at home. You can give your bulldog top points if he os she is able to get out in under 15 seconds. And if it takes more than 30 seconds, you might want to get in there and give your pup a hand.
If the dog is successful, there is also no harm in some positive reinforcement with a tasty treat.
Another unique test is based on using your dog’s favorite spot to test his or her ability to adapt to change. Consider your dog’s favorite spot in the room is and while your dog is not in the room, move some of the furniture around. When your dog re-enters the room, watch to see if he or she returns to their spot regardless of the change. If the dog successfully returns to their spot, this conveys intelligence in addition to memory skills and an acute awareness of change. Again, provide them with some positive reinforcement and a well-earned treat.
These are just a few ways that you can test your dog’s intelligence. It is also important to remember that although dogs are born with certain genes and brain chemistry, they can also pick up environmental cues and go on to adopt either positive or negative habits: this is useful for owners to remember if they are encountering behavioral issues with their dogs too. Even if your pet does not instantaneously respond to the tests laid out to them, this does not mean that with some perseverance they won’t slowly learn and develop new habits.
Can you make your bulldog smarter?
Bulldogs can be naturally stubborn by nature and part of this approach stems from their ability to consider their options and reflect. What may appear to be a negative trait can actually be useful as they will trust their own instincts and have conviction when protecting their owners. In relation to tests, tricks, and learning new behavior, they might not immediately always be onboard and some initial resistance could be the first stepping stone to pass.
Numerous techniques can be used, and are particularly beneficial if exercised from an early age. Consistency and variety mean that your dog can be kept engage and continuously keep developing new skills.
You can always continue to develop your bulldog’s mind and body. Socializing him or her with other dogs will continue to challenge them and keep them active. Another way is to continue to teach them new tricks, and find new ways to add little challenges, so that their brains are kept active. A mentally healthy and active bulldog, is a happier bulldog! | <urn:uuid:6275ceec-e55f-44c6-96f1-db65207414ad> | CC-MAIN-2022-33 | https://thebulldogblog.com/are-english-bulldogs-smart/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.969099 | 1,444 | 2.28125 | 2 |
Last January, the first mobile heart-lung machine providing ECMO treatment was introduced to the Helicopter Emergency Medical Service (HEMS) at Rotterdam Airport, where Lifeliner 2 is based. During the next 18 months, the three other Dutch HEMS stations will follow suit in introducing the service. This move has made the Netherlands the first country to have nationwide ECMO coverage in place, improving cardiac arrest patients’ chances at a full recovery.
The ECMO treatment is combined with extracorporeal cardiopulmonary resuscitation (ECPR), where the in- and outflow of blood to the heart is connected to the ECMO machine. Project initiator and leader Dinis Reis Miranda MD PhD, anaesthesiologist-intensivist and HEMS physician, spoke to AirMed&Rescue about the decision to initiate nationwide ECMO services despite the inherent challenges.
By introducing ECMO during a refractory cardiac arrest, normal circulation can be achieved, which provides advantages when blood circulation, added with oxygen through the ECMO heart-lung machine, is recovered in an early, pre-hospital, stage. This was the basic premise on which a study was based that resulted in the equipment being carried onboard the helicopters.
The Netherlands is the first country to have nationwide ECMO coverage in place, improving cardiac arrest patients’ chances at a full recovery
Specific training needed for medical crew
Reis Miranda highlighted the essential – and specifically developed – training needed for physicians and nurses to ensure they are capable of performing ECPR in order to begin ECMO treatment. To apply ECPR, two cannulas are inserted into the groin and directed to the entry and exit of the heart. To perform such a precision action under out-of-hospital circumstances, the team had several dedicated training days to ensure all procedures were thoroughly practiced in various settings. “You could find us training in the middle of a field at the airport or narrow corridor in the hangar, so we have ensured we are always prepared for any scenario,” Dr Reis Miranda explained.
Clarity of patient information defines decision making
“It is important to have early and complete patient information from our emergency room, which initiates our alert dispatch to the resuscitation incident,” HEMS nurse Christiaan explains. An initial diagnosis means the team can determine whether or not the patient can be considered for ECPR. “During our flight to the incident scene, we verify again if the available information matches the criteria for ECPR. Finally, on scene, we check once more together with the nurses from the ground ambulance and make the decision whether or not to start ECPR.”
It is important to have early and complete patient information from our emergency room, which initiates the alert dispatch to the resuscitation incident
“To continue the procedure, our tasks are split up. Ambulance paramedics concentrate on all treatment above the patient’s diaphragm, like continuation of heart massage, respiration and administration of medication,” Christiaan continued. Meanwhile, the HEMS physician and nurse concentrate on their interventions below the diaphragm. The groin area will be sterilised, veins detected and cannulas inserted, and from then, the ECMO machine can be up and running in approximately 10 minutes, and the patient will be in a stable condition not long afterwards. In the subsequent 15 minutes, the patient is made ready for transport to the hospital, where dedicated and specialized follow-up treatment can be given.
Logistics of introducing heavy equipment onboard a helicopter
The on-scene role of Lifeliner 2 pilot Roel in this process is normally limited, as he stays with the helicopter to keep the aircraft and the surrounding area safe. However, there are times when he can join the medical team and is able to give a helping hand for logistics and coordination. During the preparations of the ECMO study, for instance, Roel was closely involved with all helicopter-related issues, such as the increased weight and position of the equipment in the cabin. Although it is a mobile unit, all the ECMO equipment together comprises a large bag weighing more than 30kg, which had to be examined carefully to find the right position in the helicopter together with the HEMS equipment already onboard. The ECMO machine found its position in the back of the Airbus H135, where it did not block any crew exits and remained safely within the helicopter’s maximum weight limits. “This is of high importance for flight safety,” noted Roel. “For example, when you lose one engine for whatever reason, you still have to be able to control the helicopter’s remaining power in order to come out of that dangerous situation.” To install the ECMO onboard the helicopter, only one simple modification had to be made – the addition of an extra electric connection to keep the ECMO battery charged.
Study outcomes will determine future moves
Complete introduction of ECMO services onboard the helicopter air ambulances providing air medical coverage of the Netherlands will be reached by the end of next year. The study will include 390 patients; a figure they expect to be reach in approximately two years’ time, based on historical data. The main criteria for patients to be included in the study are, amongst others, being between 18 and 50 years old and that the cardiac arrest was witnessed. Although a patient might initially meet the inclusion criteria, there are also various criteria that may result in exclusion from the study, such as patients with a ‘do not resuscitate’ order.
When the total number of patients is reached, analyses will be done on the data gathered to present the team’s findings and conclusions. These results will form the basis for further decision making on how to continue with ECMO treatment provision onboard the helicopters. Should a positive result of pre-hospital ECMO usage is firmly supported by the study statics, the criteria may become subject to review. A possible subsequent discussion might assess the age criteria, for instance, knowing that the number of cardiac arrests increases exponentially over the age of 50. On the other hand, increasing the scope of the patients’ age will likely affect the current capacity of hospital intensive care beds, as well as the capacity of the four Dutch HEMS stations. When relevant, it will be clear that such a discussion needs to be done in a broader setting as it will involve many key players in the medical chain.
Dr Reis Miranda pointed out that pre-hospital ECMO and ECPR treatment is already operational in HEMS units in other countries. Paris, France, Berlin and Regensburg in Germany, and Albuquerque in the US, are examples of current international operations. With their local city focus, however, this makes the Netherlands the first country with a nationwide covered pre-hospital ECMO service.
The other three Dutch HEMS stations are located in Amsterdam (Lifeliner1), Volkel Air Force base (Lifeliner3) and Groningen (Lifeliner4). The helicopters and pilots are delivered by ANWB-Medical Air Assistance. The HEMS physicians and nurses from Lifeliner 2 are delivered by the Erasmus Medical Center, while the other stations receive their medical teams from nearby located trauma specialised hospitals. | <urn:uuid:b7993d98-1bfa-40b2-b5de-c05a742c2186> | CC-MAIN-2022-33 | https://www.airmedandrescue.com/latest/long-read/pre-hospital-ecmo-enters-dutch-hems | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.948108 | 1,491 | 2.046875 | 2 |
Retrospective on Ridgeway : Governing principles of controlled operations
Murphy, Brendon. (2014). Retrospective on Ridgeway : Governing principles of controlled operations. Criminal Law Journal. 38(1), pp. 38-58.
In Australian law there are few law enforcement powers as controversial as the controlled operation. Controlled operations involve authorised unlawful conduct by police or informers in the course of an investigation. Introduced as an apparent reaction to the High Court's decision in Ridgeway in 1995, controlled operations law has evolved into a national framework that aims to authorise and regulate undercover investigation at the local, national and transnational level. This article examines the scope of controlled operations in Australia, and their governing doctrinal and normative principles. The article concludes with a consideration of the role that controlled operations law plays in shaping new forms of sovereignty and the entrenchment of Richard Ericson's counterlaw thesis.
|Journal||Criminal Law Journal|
|Journal citation||38 (1), pp. 38-58|
|Web address (URL)||https://www.westlaw.com.au/maf/wlau/app/document?docguid=I709e413a895211e39551b714d2a617da&tocDs=AUNZ_AU_JOURNALS_TOC&isTocNav=true&startChunk=1&endChunk=1|
|Research or scholarly||Research|
All rights reserved
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|Publication process dates|
|Deposited||17 May 2021|
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Posted by abzu2 on December 26, 2013
Posted in: Ascension. Tagged: Noosphere, Noozoic Shift. Leave a Comment
1. Predicament or Problem. In the Noozoic, the interest is less on problems and more on process. Less on predicament and more on potential. So, in the Noozoic, the “problem” is ignorance itself, not particular bad stuff. Who speaks Noozoic? We do! Not about TUCAS, more about PIRC.
2. Premise. The premise of the Noozoic (it’s “functionality hypothesis”) derives from E=mcC and the axes shift. The premise is that, when “shifted” individuals exist and work and extend their identity, E=mc. And when this is facilitated among loving humans in a wave manner by GIFTS, then the energy (E = mcC ) is available to counteract the 1/5000 competitive disadvantage we have to survive.
3. Promise. The “promised land” that the Noozoic Shift will deliver is what has been called “paradise on Earth” – or the Kingdom of God in biblical terms, where a stable Global Community exists to ensure that humanity is successful, and where this “entity” is continuously adaptive, in right relationship, with proper identity, creating a culture that works for the benefit of all life.
4. People. The people of the Noozoic are a small minority who seek “how and now”. They see the urgency and are open. They, individually and collectively, have made their consciousness the independent variable. They have an urgent sense for the danger… maybe their children or grandchildren.
5. Process. The “how will this work”, action steps, actions and outcomes, feedback loops and the process of proof are NOT fully known and will need to emerge. The underlying principle(s) of the Noozoic can be stated (such as “All is One”). The unfolding process cannot. It is a Mystery.
6. Product. The “what” of the Noozoic is not a thing but a spirit, a culture, a consciousness, a will, an intention, a devotion to relationship, a sanity, and a planet where love is the prevailing human function. The “product” is never packaged, finished or fully done. It is, by its nature, always unfinished. There is always more.
7. Perception. The fundamental perceptual shift of the Noozoic is that All is One. From this, a set of secondary perceptual insights is derived, such as the Universe being a planet farm, where those planets which “make it” need to cross a threshold, and that this assympote has certain conditions, such as PAIR. One critical perception is a perspective on life and our place in it, which comes from the new cosmology, our journey and story.
8. Places. Where is our Jeruselem? How and where shall we promote the Noozoic Shift? This remains to be seen, but currently we shall use the Internet, our Website, http://www.noozoic.com, YouTube, Facebook and Twitter. A breakthrough would be our own custom mobile App, via VC funding.
9. Promotion. The media and method are our challenges. We need better collaborative systems, more MONEY, better interaction facilitation, professional help. Our media, method and monetization are weak. We need some tagginess such as “Nooz it or Lose it”. We need a logo, and PR materials. We need a magazine (“AMONG”?) and a “Noozpaper.”
10. Proposition. We are proposing that people think, talk and act in the best interest of all life, thereby reprogramming the Noosphere. This behavior needs to be continuous, real, conscious, and out of love for a “Power Greater.” The individual who engages with the Principles of the Noozoic will need some genuine willingness to “lose their life” and some courage too!
11. Perpetual. The Noozoic is not a thing, which happens and then is done. It is an everlasting, ongoing, forever emergence. It is like photosynthesis and gravity and light… always there. It is like breathing, an addition to the animal, which came out of the water to breath on land. Never suspended, not optional. Always necessary for life. Permanent. Like the Universe itself. Eternal.
12. Proof. The word proof, like a proof sheet in photography, means to bring into focus, to make real. In the Cenozoic, this would be facts and figures. Data and numbers. In the Noozoic, “proof” is like the good Samaritan, where it is asked, “Which one of these proved neighbor unto the person in need?” Proving neighbor is a function of OUR identity, relationship and culture. We prove neighbor. We trust the Russians. We collapse the probability wave. We are now first cause. How we SEE is the key. Worldview is fundamental. All is One is the foundation. Love is the function. Life is the process. Survival is the only outcome we could “define.” What this does mean or will mean is NOT definable. To move forward, collectively, we shall need to be aware to NOT try to put new wine in old wineskins. And to not accept the old as good.
One difficulty now is getting gross movement out of certain death into uncertain mystery. From our habituated past, we resurrect a suicidal future. Without a real Noozoic shift, we’re gonners! And the party train is racing down the tracks, and the titanium wall is real, and it is just around the corner, and the sooner we make the adjustments, the easier and better the outcome will be. But even the word “adjustments” misses the enormousness and the greatness of this opportunity.
Education is cheaper than prevention, which is cheaper than correction. Fortunately, the Cosmos is fully designed for our new emergence. We have GIFTS. The time is right. The danger/opportunity pressure is right. We can fulfill the Noozoic with less uncertainty than we think. The whole Universe is standing by, awaiting our return. Listening for a signal that we are awake. Wanting the best for us. Always there.
We need to seek, ask and knock. We need to put our hands to the plow and not look back. We need to enjoy the incredible unfolding as it’s own reward. We are designed for this shift. We can do it! We must do it!
Failure is not an option… | <urn:uuid:765d8776-623d-4ae4-a977-c6084378396c> | CC-MAIN-2022-33 | https://www.oom2.com/t17157-what-is-the-noosphere | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.94555 | 1,425 | 2.421875 | 2 |
Sleep system sensitization: evidence for changing roles of etiological factors in insomnia
Kalmbach DA, Pillai V, Arnedt JT, Anderson JR, and Drake CL. Sleep system sensitization: evidence for changing roles of etiological factors in insomnia. Sleep Med 2016; 21:63-69.
OBJECTIVES: To test for sensitization of the sleep system in response to insomnia development and major life stress. In addition, to evaluate the impact on depression and anxiety associated with sleep system sensitization.
METHODS: A longitudinal study with three annual assessments. The community-based sample included 262 adults with no history of insomnia or depression who developed insomnia one year after baseline (67.6% female; 44.0 ± 13.4 yr). Measures included the Ford Insomnia Response to Stress Test to assess sleep reactivity, Quick Inventory of Depressive Symptomatology, and Beck Anxiety Inventory. Insomnia classification was based on DSM-IV criteria. Sleep system sensitization was operationally defined as significant increases in sleep reactivity.
RESULTS: Sensitization of the sleep system was observed from baseline to insomnia onset at 1-yr follow-up among insomniacs with low premorbid vulnerability (p < 0.001), resulting in 68.3% of these individuals re-classified as highly sleep reactive. Major life stress was associated with greater sleep system sensitization (p = 0.02). Results showed that sleep reactivity at 2-yr follow-up remained elevated among those with low premorbid vulnerability, even after insomnia remission (p < 0.01). Finally, analyses revealed that increases in sleep reactivity predicted greater depression (p < 0.001) and anxiety (p < 0.001) at insomnia onset. The impact of sensitization on depression was stable at 2-yr follow-up (p = 0.01).
CONCLUSIONS: Evidence supports sensitization of the sleep system as a consequence of insomnia development and major life stress among individuals with low premorbid sleep reactivity. Sleep system sensitization may serve as a mechanism by which insomnia is perpetuated. Harmful effects of the sensitization process may increase risk for insomnia-related depression and anxiety.
Medical Subject Headings
Adult; Anxiety; Arousal; Brief Psychiatric Rating Scale; Depression; Female; Humans; Longitudinal Studies; Male; Sleep; Sleep Initiation and Maintenance Disorders; Stress, Psychological; Surveys and Questionnaires | <urn:uuid:fce12573-546e-48ad-83a1-17f0487dd1bf> | CC-MAIN-2022-33 | https://scholarlycommons.henryford.com/sleepmedicine_articles/73/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.896791 | 551 | 1.539063 | 2 |
For many applications e.g. in an isolator environment it is virtually impossible to place conventional wired temperature sensors. For this reason, freeze drying cycles with these units are usually conducted without temperature measurement, relying instead on validation runs.
In response to the Process Analytical Technologies (PAT), we have taken a new course and use the WTMplus 2.0 wireless product temperature measurement system for freeze drying. The wireless self-powered sensors are placed manually or automatically when the product vials or dishes are filled and report the corresponding product temperatures to the unit controller during the entire lyophilisation process. The WTMplus 2.0 temperature sensors are operating battery-free.
- Wireless power transfer to the temperature sensor by an HF signal in the 2.4 GHz frequency band
- Temporary energy storage in an oscillating quartz crystal
- Highly accurate temperature-dependent shifting of the quartz crystal resonant frequency
- Feedback of the frequency shift and temperature determination using sophisticated electronic signal processing
- Falsification of the measured product temperature is avoided by the passive structure without batteries and the extremely low operating power level.
- Several different sensor frequencies can be used to monitor different sensor positions.
- Definition of any sensor locations for automatic loading/unloading.
- Interference-free wireless data transfer worldwide in the 2.4 GHz frequency band
- Active frequency selection ensures stable signals at every location, even with freeze dryers made entirely from stainless steel.
- Measurement accuracy ±0.5 K; max. ±1 K
- Covers the entire process (temperature range –60 °C to +135 °C)
- Wirelessly transmitted measurement data is available to the LPCplus control software for process monitoring and control
The innovative WTMplus technology is available for all Christ pilot and production freeze dryer with LSCplus an LPCplus/Siemens PLC S7.
Wireless Temperature Measurement WTMplus 2.0
The wireless product temperature measurement system WTMplus 2.0 from Martin Christ makes wireless sensor-based product temperature measurement possible for freeze drying. Automatic identification and localization of the sensors by RFID. | <urn:uuid:b5ab7ffd-edc9-4a15-96d6-15268ea2365a> | CC-MAIN-2022-33 | https://www.martinchrist.de/en/freeze-drying/wtmplus | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.86805 | 448 | 1.734375 | 2 |
Opioids are sometimes called narcotics, and their misuse has grown rapidly in Mougins. The area of Mougins is experiencing an Opioid epidemic, on an even greater level than the United States. Opiates freely available in Mougins include prescription pain relievers, such as oxycodone, hydrocodone, fentanyl, and tramadol. The illegal drug heroin is also an opioid. Some opioids in Mougins are made from the opium plant, and others are synthetic (man-made).
A local doctor in Mougins may give you a prescription opioid to reduce pain after you have had a major injury or surgery.
Opioids can cause side effects such as drowsiness, mental fog, nausea, and constipation. They may also cause slowed breathing, which can lead to overdose deaths in Mougins.
Proceed to the emergency room in Mougins for the following opiate overdose symptoms:
Other risks of using prescription opioids in Mougins include dependence and addiction. Dependence means feeling withdrawal symptoms when not taking the drug. Addiction is a chronic brain disease that causes a person to compulsively seek out drugs, even though they cause harm.
Opioid misuse, addiction, and overdoses are serious public health problems in Mougins. Another problem is that more women in Mougins are misusing opioids during pregnancy. This can lead to babies being addicted and going through withdrawal, known as neonatal abstinence syndrome (NAS). Opioid misuse may sometimes also lead to heroin use, because some people switch from prescription opioids to heroin.
The main treatment for prescription opioid addiction in Mougins includes medicines, counseling, and support from family and friends.
This approach has been proven to be ineffective in the long term.
Remedy Wellbeing is accepting patients from Mougins.
Remedy Wellbeing is an award winning luxury rehab facility with a dedicated french speaking team. The specialists at Remedy Wellbeing are World Class experts on addiction recovery and have phenomenal long term success rates with clients from Mougins and the surrounding areas.
Remedy Wellbeing allows clients to escape from their environment and recover away from the stresses and triggers back home in Mougins. Opioid treatment at Remedy Wellbeing provides the best chance for long term recovery.
Mougins (French: [muʒɛ̃]; Occitan: Mogins [muˈʒis]; Latin: Muginum [muːˈɡiːnũː]) is a commune in the Alpes-Maritimes department in southeastern France.
It is located on the heights of Cannes, in the district of Grasse. Mougins is a 15-minute drive from Cannes. The village is surrounded by forests, such as the Valmasque forest. In the village there are pines, olives, and cypress trees.
Anyone who takes opioids in Mougins is at risk of developing addiction. It’s impossible to predict who’s vulnerable to eventual dependence on and abuse of these drugs. Legal or illegal, stolen and shared, these drugs are responsible for the majority of overdose deaths in Mougins today.
Addiction in Mougins is a condition in which something that started as pleasurable now feels like something you can’t live without. Doctors in Mougins define drug addiction as an irresistible craving for a drug, out-of-control and compulsive use of the drug, and continued use of the drug despite repeated, harmful consequences. Opioids are highly addictive, in large part because they activate powerful reward centers in your brain.
Opioids trigger the release of endorphins, your brain’s feel-good neurotransmitters. Endorphins muffle your perception of pain and boost feelings of pleasure, creating a temporary but powerful sense of well-being.
When you take opioids repeatedly over time, the same dose of opioids stops triggering such a strong flood of good feelings. This is called increased tolerance. One reason opioid addiction in Mougins is so common is that people who develop tolerance may feel driven to increase their doses so they can keep feeling good.
Because doctors in Mougins are acutely aware of opioid risks, it’s often difficult to get your doctor to increase your dose, or even renew your prescription. Some opioid users who believe they need an increased supply turn, at this point, to illegally obtained opioids or heroin. Some illegally obtained drugs in Mougins, such as fentanyl (Actiq, Duragesic, Fentora), are laced with contaminants, or much more powerful opioids. Because of the potency of fentanyl in Mougins, this particular combination has been associated with a significant number of deaths in those using heroin in Mougins.
Don’t stop opioid medications without a doctor’s help. Quitting these drugs in Mougins may abruptly cause severe side effects, including pain worse than it was before you started taking opioids. Your doctor in Mougins can help you taper off opioids slowly and safely.
Opioids are most addictive when you take them using methods different from what was prescribed. This life-threatening practice is even more dangerous if the pill is a long- or extended-acting formulation.
The length of time you use prescribed opioids in Mougins also plays a role. Researchers have found that taking opioid medications for more than a few days increases your risk of long-term use, which increases your risk of addiction.
Known risk factors of opioid misuse and addiction in Mougins include:
In addition, women in Mougins have a unique set of risk factors for opioid addiction. Women are more likely than men to have chronic pain. Compared with men, women are also more likely to be prescribed opioid medications in Mougins, to be given higher doses and to use opioids for longer periods of time. Women in Mougins may also have biological tendencies to become dependent on prescription pain relievers more quickly than are men.
Opioids are safest when used for three or fewer days to manage acute pain, such as pain that follows surgery or a bone fracture.
If you’re living with chronic pain, opioids are not likely to be a safe and effective long-term treatment option.
The most important step you can take to prevent opioid addiction in Mougins Recognize that no one is safe, and we all play a role in tackling the grip these drugs currently hold on our loved ones and communities.
If you, or someone you care about has a problem with Opioid addiction in Mougins contact Remedy Wellbeing for the most successful Opiate Treatment in Mougins.
Remedy Wellbeing France is one of the best treatment facilities in the World. Worthy of true Luxury Rehab status the leading clinical team harmoniously deliver person centric bespoke treatment in spectacular surroundings for long term recovery.
If you or someone you know of is experiencing an immediate opioid overdose in Mougins call 112 immediately | <urn:uuid:9117647a-bc26-4d95-9dfc-12bb6dc0ea7e> | CC-MAIN-2022-33 | http://opiaces.fr/opiate-treatment-in-mougins/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.941956 | 1,444 | 2.609375 | 3 |
The pandemic triggered a rush to trusted sources of information, showing again the value of independent journalism, but the challenge is translating that to revenues. The loss of journalistic resources together with an onslaught of misinformation polluting the information ecosystem has also weathered trust in media compared with earlier times when journalism was at the forefront of the democratic resurgences across Africa.
How did the credibility crisis come about? How might media organizations and individual journalists withstand political and economic pressure? How do media retain experience in newsrooms, and encourage the best to join the craft? How might the media itself become more innovative? And what part has the media itself played in creating the credibility crisis and can it be undone?”
These are some of the urgent challenges for journalism in Africa according to Christoph Plate, who leads the KAS media program in Sub-Saharan Africa. This decline in media quality is partly to do with the economics of journalism, but also for some journalists, a failure to distinguish between journalism and activism.
With the pandemic driving readers to news sites, “the connection between credibility and economics persists even stronger” he told the IPI World Congress. How can the media maintain and sustain this trust and credibility?
We need a government that strongly believes in democracy and free speech
Ethiopian media is operating in a hostile environment. “But we always have to rise above our challenges and hope for a better day”, said Amanyehun Sisay, executive editor of the Ethiopian Business Review (EBR) before listing the obstacles standing before his two publications, EBR and the Amharic language weekly Addis Maleda. “Media as a business is never an encouraged investment and journalism as a profession is not appreciated,” he said. “Operating in this context, especially under an authoritarian regime, is quite difficult.”
According to Sisay, the politicized media landscape is torn between two narratives that follow the ethnic divisions in the country.
“So the content is based on the media institution’s political interests” he said, “but the real issues are not discussed … political issues are only discussed on social media, where people can stay anonymous.” But Sisay is not entirely optimistic about the role of social media in the country’s media landscape. “We have a worrisome spread of fake news, stemming from the fact that as mainstream media weakens and fails to provide enough information, people search for it on social media instead.”
One strategy to build credibility for Sisay has been to expand the media offering to Amharic language, which brings a much broader readership and satisfies a need in the community for quality, verified information.
The next generation of journalists is also endangered, according to Sisay: “Most journalism schools are government owned, and they flood the industry with poorly educated journalists.” Based on his experience, Sisay said graduates from government owned schools “are not well equipped to report fairly,” and need a lot of training. Furthermore, due to the industry’s financial situation many leave the profession as soon as possible. “We rarely have journalists with a decade or more of experience in the field.”
People pick media outlets almost like they pick football teams
The media in South Africa is divided and “those divisions are becoming more pronounced”, according to Simon Allison, Africa editor of the Mail & Guardian and The Continent. “A website like the Daily Maverick could publish an investigation and there will immediately be a section on social media dismissing it as ‘white monopoly capitalist’ even before reading the investigation.”
But he is positive about the future: “While the pandemic had a devastating impact on the finances, it also played a key role in restoring trust in journalism. The number of people coming to our website was extraordinary. What that showed us, is that when times are tough, they turn to places that they know they can trust.”
While he notes there is better media literacy and people are becoming more aware of the need for independent journalism, the challenge is translating that to revenue. “The economics of journalism is the greatest threat to journalism” he says. “Good journalism is expensive, takes a lot of effort and behind the scenes work, you can’t really skimp on it.”
He also wants to encourage donors to support the media: “The entire civil society depends on having accurate reliable news. Without it there is nothing.” But he cautions against funding specific projects, and instead “funding core news reporting so that there can be a broad base of news from which to work from.”
Allison points to the Gupta leaks story that was a collaboration of media houses as “extraordinary”. “That more than anything else was a reminder to people that journalism is powerful. With great power comes great responsibility. We have to uphold the highest standard possible but also find new ways to connect with our audiences, to make sure we are speaking to potential audiences where they are, and make sure our journalism evolves with our audiences.”
Sisay agrees that “the trick is to find new audiences. That’s where it requires a lot of bold and innovative thinking within the newsroom. I’d like to see a lot more of that.”
For Allison, one of the clues is understanding that it’s a natural desire for humans to want to share information. “It makes us what we are, keeps us a society. What we’ve done a bad job of is giving people information in a way that they can share it. WhatsApp is a great example of this. Almost no major media house has any presence on this medium. The only people making news on WhatsApp are people making fake news.”
* This panel discussion was organized in partnership with Konrad Adenauer Foundation (Media Programme Subsahara Africa).
** Joan Chirwa, founder of the Free Press Initiative in Zambia, announced as one of the speakers, was not able to join the discussion. | <urn:uuid:0ca0778e-6d11-40ed-a721-1639c6a08ee5> | CC-MAIN-2022-33 | https://ipi.media/media-credibility-and-trust-needs-investment-in-journalism/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.963624 | 1,272 | 2.296875 | 2 |
Urushiol Oil is Potent
- Only 1 nanogram (billionth of a gram) needed to cause rash
- Average is 100 nanograms for most people
- 1/4 ounce of urushiol is all that is needed to cause a
rash in every person on earth
- 500 people could itch from the amount covering the head of a pin
- Specimens of urushiol several centuries old have found to cause
dermatitis in sensitive people.
- 1 to 5 years is normal for urushiol oil to stay active on any surface
including dead plants
- Derived from urushi, Japanese name for lacquer
When the Japanese restored the gold leaf on the golden Temple in
Kyoto, they painted the urushiol lacquer on it to preserve and
maintain the gold. Guess you could say that you would be caught
red handed if you stole it.
How do you.... | <urn:uuid:9fa10f47-6d54-435e-9195-80e10fd4e5a7> | CC-MAIN-2022-33 | https://poisonivy.us/view/fastfacts.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.943351 | 192 | 2.15625 | 2 |
It was written, produced and directed by R John Hugh, hardly a name to set the Western-lover’s blood coursing hotly through her or his veins, and it starred the equally unstellar Lin McCarthy and Stephen Courtleigh, pretty well unknown to Westernistas and in their only leading roles in our noble genre.
Still, the true-hearted aficionado will not be put off by that.
It’s one of those plots in which a small band of men make an arduous trek, beset by Indians and the perils of raw nature. We know right away that one by one the party will be whittled down until the few survivors, or maybe even only one survivor, will finally win through. Probably the mean and low members of the group will expire first, deserving it, then a brave one will make a self-sacrifice, and it will be the innocent and/or young one who makes it through. It usually was. Often the hero and his gal (for they usually contrived to have a girl in the gaggle) won out but this time there is no female; there are only tough men.
The twist in this one is that it is set in the Everglades, and the hostile Indians are Seminoles. That was unusual but not unknown. There was a small sub-genre of Seminole Westerns. In the early 1950s, Hollywood, tired perhaps of traditional non-specific ‘Indians’ in standard attire from central casting’s costume department, suddenly developed an interest in the Florida Seminoles, and Westerns started to appear featuring them. Or rather, Hollywood rediscovered an interest, for there had been silent movies about the people, such as The Seminole’s Trust (1910), The Seminole’s Sacrifice (1911) and The Virgin of Seminole (1923).
There were three early 50s big-studio films about the whites’ wars against the Seminoles, all historical bunkum.
R John Hugh seems to have liked Florida settings, though, for he set several of his pictures there, and, though born in London, England, he died in Orlando, Fla. (where Yellowneck was premièred). One of his movies, a Western, was Naked in the Sun, another Empire Productions effort, this time released by Allied Artists, an 1830s story in which an unscrupulous slave trader captures the wife of Chief Osceola, setting off a war between the Seminole tribe and the U.S Army. We’ll review that another day. Maybe.
Lin McCarthy plays a deserter, and the intro tells us that Confederates used the term yellowneck to describe runaways from the fighting. I’ve never really known why cowards are described as being yellow. The color has been associated with those whom society despises for some time: Judas is often shown in yellow in art, Cathar heretics were forced to wear yellow crosses, the Jews had to sew on yellow badges in the Middle Ages (and stars in the Nazi era), and it was Venetian prostitutes’ signal color. I am informed that yellow-bellied for cowardly was first seen definitively in English language print only as late as 1924, in Percy Marks’s The Plastic Age when he wrote about “yellow-bellied quitters.” See, I’ve done my research. Maybe it’s true that Reb deserters were called yellownecks. Or maybe it’s made up. Why their necks would be that color rather than their bellies is a mystery. Oh well. Where was I?
Oh yes, Lin McCarthy. Pretty well an unknown, he was an unlikely Western lead. Although he did appear in a few Western TV shows, he had only been in one other feature oater, as the sheriff in Fred MacMurray’s 1959 picture Face of a Fugitive. In Yellowneck he plays the sergeant, leader of the small band of deserters down in Florida trying to get to Cuba. He is a slightly sympathetic figure, not a cowardly renegade but a brave man sickened by the slaughter and not able to cope with the bloodshed any more.
The three he leads are two reprehensible older men, lowlifes who will stoop to anything, and a green boy. These three have deserted for less noble motives. Plunkett (Berry Kroeger) has a pouch of gold he has stolen from the Confederate army which he believes will fund his old age in Cuba. Cockney, an Englishman (Harold Gordon, born not within the sound of Bow bells in East London but in Brooklyn, and with a Cockney accent that probably served as the model for Dick Van Dyke) is equally unpleasant. The two despise and goad each other. Bill Mason, in his only ever film, plays ‘The Kid’, although he looks a bit long in the tooth for such a role. None of these actors will be immediately recognized by Western fans.
The quartet are joined by a lone wandering colonel (it is never explained quite what he was doing strolling about the Everglades alone) played by Stephen Courtleigh, another actor hardly famed for his Westerns, or indeed for anything else. Like McCarthy he popped up in the odd Western TV show. He had an uncredited bit part in North to Alaska and that was his only other big-screen Western. He is a noble officer, though, unjustly maligned for drunken cowardice, it turns out, but rather decent, though he defers to the command of the sergeant. He bravely tackles a gator with his saber and is badly wounded by a Seminole arrow in the back. He manages to shame the others into behaving semi-decently when he stays behind to bury two other deserters they find who have been killed by the Seminoles, and the band eventually return to help him. He is the first to perish.
One of the Indians is played by Roy Nash Osceola, presumably a real Seminole, which is nice. The Indians, though, are only glimpsed here and there and occasionally seen to be shot down by the ex-soldiers.
Cockney is terrified of snakes and it is poetic justice when a rattler gets him. He dies immediately, unlikely from a rattler bite, but he was so afraid of the slithery reptiles that he probably had a heart attack. Plunkett sees the snake but doesn’t do anything to save Cockney, the swine.
The trouble with these stories is that the rhythm of the picture moves along at the walking pace of the men staggering through the swamp. It’s hardly superfast breakneck action (though Cockney did try to break Plunkett’s neck by pushing him under a falling tree, the skunk, so Plunkett was getting his own back with that rattler). You just get men trudging slowly, punctuated by soliloquies and the occasional flurry of danger.
Reduced now to just the sergeant and the youth, the survivors press on. The sergeant tells the kid, “Don’t run away from nothing, Kid. It don’t do no good.” Once you get through the brace of double negatives you feel he may be right. At any rate he it is who sacrifices himself, suffering a grisly fate in a quicksand (the scene showing his hand last to disappear is in fact quite powerful), to allow the young man to escape and reach the ocean, and thence, presumably, to Cuba.
It’s in color (Republic’s Trucolor process). An apparently knowledgeable reviewer on IMDb tells us that “The scenes that take place during a storm were actually shot during a hurricane that visited Florida during the shooting schedule. Snakes used in the scenes came from a local tourist trap called Alligator Farm. Many of the exterior scenes were made in Altamonte Springs area.”
It makes a change from some of the other Seminole Westerns in which sundry creepy crawlies and wild critters are very obviously footage from other movies cut in. The reviewer adds:
“The quicksand scene was actually a pit that was dug about chest deep and filled with leaves, etc. The actor got in and faked the sinking part. The hand going down was actually a closeup of him just pulling down his arm (trick photography 50s style). The Florida panther that jumps out of the tree was a fake that was pushed from behind by a guy with a pole. Looks real though.”
The DVD is 72 minutes long but the full 83-minute version is on YouTube. Probably the shorter one is better.
Well, you could watch it, I guess. | <urn:uuid:3af607a0-305d-4894-922d-b0bde8be8a67> | CC-MAIN-2022-33 | https://jeffarnoldswest.com/2018/05/yellowneck-republic-1955/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.979259 | 1,848 | 2.03125 | 2 |
My grandmother, Ann, did not take shit from anyone: she raised five kids, dealt with an alcoholic spouse and once threatened to stab the abusive husband of one of her daughters. You did not want to get on her bad side. She was also warm, hilarious, a beautiful singer and a doting grandma. But if you didn’t know her – if you just heard her cursing up a storm or saw her complaining to the grocer – you might find her a bit harsh.
Grandma Ann has been dead for years, but I wish I could ask her how she remained such a loudmouthed badass during a time when, for women, being that way could mean social ostracization or acceptable physical abuse. For most women, we’re so keen on being likeable that just the idea of people actively hating you or finding you “disagreeable” can be brutal.
Women are taught from the time that they’re girls to be pleasing, cheerful, and cute – so much so that men feel entitled to tell women they do not know that they should “smile” more, or that we should demonstrate boundless joy while doing domestic work (I’m looking at you, Kirk Cameron). Women are even expected to be fun-loving while running for public office, lest they’re painted as a ballbusting harpy or nags or bitches; there’s no lack of words used to mean “threatening woman”. Men in charge are bosses, women are bossy. Men are all-business, women are cold. Men are insightful, women are depressing.
And, when the default expectation for women’s personalities is sweetness and pep, it’s easy to mistake seriousness for nastiness. For women of color, almost any personality trait is labeled immediately as “angry”. Too many people don’t seem to understand that women – who are human beings – contain multitudes and are able to be serious, fun, grumpy, and loving within a short period of time (if not all at the same time).
It’s a mistake to confuse women’s solemnity with anger; it’s an even bigger one to disparage angry women. It not only teaches young girls that legitimate feelings are somehow “undesirable” – and that they should plaster a fake smile on anytime they’re hurt or angry – but it also diminishes the importance of anger and taking serious things seriously.
In the immortal words of Tina Fey: “Bitches get shit done”. You might, in fact, catch more flies with honey, but what if you’re more interested in raising your kids and keeping your daughter’s husband from hitting her again? Angry and ornery women are strong and capable and smart and aren’t keen to be walked all over.
And there’s plenty for us to be angry about! It’s not as if the world is a joy-filled wondrous place for for us – we still have to deal with discrimination and violence at epidemic levels.
So instead of worrying too much about how I come across to other people, I try to channel my grandmother and embrace my most caustic self instead. I come from a long line of pissy, sarcastic women who I know would be proud of me no matter what – but even more so if I didn’t take crap from anyone. | <urn:uuid:24f28a1f-8e52-49f8-b9f8-cfcbf2dff327> | CC-MAIN-2022-33 | https://www.theguardian.com/commentisfree/2015/feb/02/women-worry-being-liked-being-effective | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.956573 | 722 | 1.867188 | 2 |
Little baby teeth have some big responsibilities. They not only help you bite, chew and speak correctly but also help guide the permanent teeth underneath them into proper position.
Caring for your child’s baby teeth or milk teeth can not only help in maintaining a great smile but also in general well-being.
Establishing a good oral hygiene routine while they are still young can have a lifelong impact.
One of the most important roles baby teeth have is preparing the space for proper alignment and growth of permanent teeth.
A baby tooth holds the space for the adult teeth and remain in its place until it’s pushed from underneath by a permanent tooth or due to an injury.
Dentists in dental clinics in Delhi are making patients aware about the negative implications that their children can experience if they lose baby teeth prematurely.
When a baby tooth is lost prematurely, the permanent teeth on either side of it may gradually move or tilt towards the empty spot instead of where they should be.
They drift into the space that was reserved for another tooth. This can cause teeth to erupt out of position or to be blocked entirely, and this could result in permanent teeth coming in crowded or crooked.
When more permanent teeth are ready to come into the mouth, there may not be enough room for them because of the lost space.
The space maintainer preserves the space for the permanent tooth to come in. It will prevent the other teeth from moving into the empty space.
If left untreated, the improper growth of permanent teeth can easily result in extensive orthodontic treatment.
Actually, all baby teeth are like space maintainers since they are in the best chiropractor in San Diego Fix Body Group until the permanent teeth are ready to come in.
A space maintainer is important because its main purpose is to preserve the space for the permanent tooth to come in, therefore, not allowing the rest of the teeth to shift or move.
They are placeholders to keep space for incoming permanent teeth when a baby tooth is lost early, or when your child needs an extraction due to decay or injury.
Sometimes children lose a baby tooth from decay or injury before a permanent one is ready to come in. This can lead to dental issues down the road.
If a tooth is lost or extracted before its permanent successor is ready to erupt, other teeth may work their way in or around that open space instead of where they should be.
Dentists in India are taking care to counsel the parents on the adverse effects this will have on their other teeth and bite.
When the baby tooth is gone, the surrounding teeth may shift their position or grow in a way that reduces the amount of room available for the permanent tooth to come in.
This can affect your child’s speech and ability to chew. Eventually, your child could need orthodontic treatment to correct the problems caused by one missing baby tooth.
To prevent this from happening, the dentist may recommend a space maintainer to hold open the space left by the missing tooth.
The longer baby teeth are maintained, the easier for permanent teeth to emerge in proper alignment.
Space maintainers are not permanent and they can be removed when permanent teeth erupt. These easy and comfortable devices hold the space for the permanent teeth’s future slot and keep the surrounding teeth from infringing on the area.
Once the permanent tooth has erupted, then the maintainer can be removed. You will want to make a follow-up appointment for x-rays to check on the progress of your child’s treatment.
Space maintainers can take several forms depending on the age of the patient, the tooth location.
Removable space maintainers can include an artificial tooth to maintain the position of the teeth, and are best suited for older children who can be responsible for cleaning the appliance regularly.
It maintains the amount of space available in the mouth and prevents unwanted drift of surrounding teeth so the permanent teeth have a chance to erupt correctly.
It is very important that your child continues to visit the dentist for regular checkups, especially to monitor the progress of the space maintainer and the permanent tooth below it.
The space is also necessary to ensure that the permanent tooth will have plenty of room to come in without pushing behind or in front of neighboring teeth that may have shifted.
Dental clinics in Delhi are counseling patients on the importance of the use space maintainers.
A space maintainer will make sure that the teeth around the space do not shift. If these teeth shift, then they may hinder the incoming permanent tooth. This tooth will not have room to come into the open space if the surrounding teeth shift in to fill the gap.
These are devices that fill the space left by a missing tooth. They are custom fitted to your child’s mouth, and they keep the other primary teeth in place so permanent teeth can come in where they belong. The dentist removes the appliance when the permanent tooth above the missing one is ready to emerge.
It’s a simple, non-invasive way we can avoid a malocclusion (bad bite) with some timely intervention.
Caring for space maintainer
Whatever space maintainers you and your dentist have decided to use for your child’s current condition, good oral hygiene must be practiced at all times.
It is essential that your child maintain proper oral hygiene to help their appliance last longer and prevent decay on the other teeth.
It might take a few days for your child to get comfortable with the appliance.
Brushing and flossing around and under the retainers is very important to help your child in healthy growth and development of permanent dentition.
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In fall 2021, a new edition of “O’Hara’s Heirs: Business Education at Notre Dame” will be published that covers the College’s entire 100-year history. Information about ordering the book will be available at mendoza.nd.edu/century-mark.
I wonder what sort of tale we have fallen into?” Sam asks Frodo in a passage from J.R.R. Tolkien’s Lord of the Rings trilogy. I asked myself a similar question when I was handed the assignment to write the story of Notre Dame’s College of Business. “What sort of tale,” I wondered, “is the College’s history?”
Fortunately, like Sam in Tolkien’s story, I wouldn’t be on my own in answering the question. My task was to build on a story that had already been told by Kerry Temple in the book “O’Hara’s Heirs: Business Education at Notre Dame, 1921–1991.” I was to detail the College’s next act, the years 1991–2021, for its centennial celebration.
So I began to revisit my own spine-creased, dog-eared copy of the book looking for clues. I also began interviewing dozens of current and former administrators, faculty and students. It didn’t take long for an answer to my question to come into view: This is a David and Goliath story.
You see, nearly everyone could remember times when the College was written off or underrated. Faculty and administrators in particular recounted times they heard colleagues at other universities say Notre Dame would never compete with the best business schools. Compared to the competition, they were told, it was too small, or too far from major cities, too liberal arts-focused, too religious or even too preoccupied with ethics to lead in the world of business education.
To make matters even more difficult, the College sometimes faced questions about its very existence from within the University. An October 1985 issue of Scholastic magazine featured a close-up image of a business suit with text superimposed over it that read, “Does Business Have any Business at Notre Dame?” In the issue, one writer asked, “The University boasts a traditional commitment to academic excellence and a liberal education. But how valid is this claim when the University also offers an undergraduate business major?”
Amazingly, questions like this don’t appear to have created a crisis of confidence for the College. Quite the opposite. They have acted like a refiner’s fire, forcing it to clarify its mission and strive for a higher purpose as the business school at Notre Dame. Former University President Fr. Ted Hesburgh captured a bit of that dynamism when he said, “Through the years there has been talk of dropping the College. I always felt that as long as we had one, we might as well make it the best it could be.”
You might think that the underdog part of the College’s story ended sometime in the last 30 years. After all, during this time the College met and exceeded nearly everyone’s expectations of it. It reached the top spot in some of the nation’s most competitive rankings. A series of crises — the Enron collapse and the financial meltdown of 2008, to name a few — have shown that the College’s emphasis on ethics is an asset, not a liability. And not only has the College become Notre Dame’s largest; its achievements and positive impact have become a special point of pride.
What stands out in the narrative, though, is that the David and Goliath story continues today, and that is because the “Goliath” in question was never the College’s critics or detractors, whether they are inside or outside the University. Rather, the giant the College has always aimed at taking on is as big and wide as the world itself.
The College’s founder and first dean, Father John Francis (later Cardinal) O’Hara named this giant in a quote popularized by the first edition of “O’Hara’s Heirs.” “The primary function of commerce,” O’Hara wrote when his new College was just two years old, “is service to mankind.
Visit mendoza.nd.edu/century-mark to read a series of “Make Your Mark” essays, contributed by alumni, faculty and staff who added their marks to the College timeline through personal and highly individual reflections on the impact of Notre Dame on their lives.
Make your own mark in Mendoza’s history by submitting your essay and photo to email@example.com. | <urn:uuid:f0bad2d2-9aaa-46ed-9854-7605543cec3c> | CC-MAIN-2022-33 | http://bizmagazine.nd.edu/issues/2021/spring-2021/century-mark/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.967403 | 998 | 1.664063 | 2 |
The food manufacturing industry has always been concerned with the quality and safety of the food they produce. At the very lowest level, it is an unwritten ethical requirement. But the topic of food safety and quality has never been in the news like it is now.
There are many reasons for this increased awareness of food safety. Among them are government regulations, consumer demands, social media, education and the complex food supply chain.
Government regulations and consumer demands are listed as numbers one and two respectively. Frankly, these can be flipped. Governments have always dictated food policy, but over the last five to 10 years the consumer has not only been driving the government’s efforts but the manufacturers. Let’s face it. The entity that controls the purse strings usually has the last word.
Consumers are increasingly taking an interest in quality, health benefits and a more serious interest in the foods and beverages they consume. With today’s expanded media coverage, social media and multiple avenues of information, the consumer now has an input on food safety. Last but not least is the supply chain. Today’s supply chain is more complex and the value chain has expanded. The consumer food buying process has changed. There are more stopping and touch points in food transport and movement. This is where many of the compromises occur.
Touch points and stopping points
Food manufacturing and distribution used to be quite simple. There were many less products, many less ingredients and many less places for a consumer to acquire these products. Today’s value chain includes traditional grocery stores, club stores, convenient stores, internet buying and home delivery of both domestic and international product. These elements have added more touch points to the process.
To keep food safe through this complicated process, all activities and who performs them through the supply chain need to be understood and the processes need to be perfected.
We need to understand all the components of the food supply chain from field to fork. To effectively manage the process to ensure food safety we need to analyze each component of the chain. Major elements of the food manufacturing supply chain to consider are:
- Raw Material/Ingredient Procurement Process.
- Food Manufacturing Process.
- Finished Goods Distribution Process.
- Finished Product Sales Point.
These are the major areas of the supply chain that can impact food safety. If you notice, they are the same areas that are addressed in overall supply chain management (SCM), or Supply Chain Planning (SCP), or Integrated Business Planning (IBP) or Sales and Operations Planning (S&OP). You get the picture. So why not utilize these processes at the same time to execute FSSCP (Food Safety Supply Chain Management)?
In managing the supply chain, these areas are managed by distinct functions then integrated through a collaborative management and communication process using one of the names above. Adding a few tasks to the process can ensure food safety is addressed while managing the supply chain.
The Procurement Process
There are a variety of materials that are needed to produce finished food products. They include ingredients, raw materials and packaging supplies. The goal is to get the right quantities at the right time at the best costs to get customer the products they want when they want them while garnering the best margin for the manufacturer.
Any material, ingredient or item used in the production process can introduce contaminants.
Technology is available today and continuing to develop to trace all ingredients and materials back to the original source. Companies inspect produce, proteins, and flavorings, chemicals and spices as they enter the facility.
What about packaging materials? To what level are they tested? To what level of packaging manufacturing is traceable? Can the ink be verified as food safe? It is paramount that every component of every package of finished food can be traced to original batch and original grower and supplier.
Many times contamination of ingredients and supplies occur during transport from the source to the manufacturer. Exposed bins, trucks, crates and other vessels can make items prone to contamination. The cleaning process at the manufacturing facility might not be able to solve the problem if contamination has occurred. All information about the transport the vessel, route and who handled the products need to be tracked, traced and documented.
The Food Manufacturing Process
Effective management of plant operations is critical to a food manufacturer’s profitability and ensuring food safety. Contaminations can occur through a number of issues in the production process, including operator procedures, equipment issues, environment and temperature control
Tracking material movements through the manufacturing process is essential. Many products have temperature requirements that cannot be violated. Monitoring the movement through the process is a daunting task.
There are a wide number of opportunities for a safety breach. Worker contamination, bacteria and allergens on equipment, improper environmental and facility conditions can lead to contaminations. In addition, frequent schedule changes, production delays, machine breakdowns, unnecessary material movement can all lead to more stopping points where food safety can be compromised.
The Finished Goods Distribution Process
Food distribution has never been more complicated. Gone are the days of a simplified network that consists of plant to dc to store. Manufacturers warehouses, 3PL’s, company owned trucking, 3PL trucking, distributors, Customer DC’s, customer satellite warehouses and other selling locations all spell trouble for food safety.
Sell by, use by, best by, best before dates and other terms to indicate food freshness complicate the process. Today, individual retailers have their own shelf life dates and rules. These factors contribute to potential breaches to food safety in the supply chain. If there is an issue it typically falls back to the manufacturer to provide all the critical information about the products lifeline.
Finished Product Sales Point
One might assume that once a finished food product arrives at the point of sale the manufacturer’s responsibility ends and the safety guarantee now rests with the seller. This is a touchy subject and many factors play a role in the question of who is now responsible for food integrity. The manufacturer still holds accountability as the producer but the retailer and any third-party group involved in product movement share responsibility.
Keeping the links intact
The objective of the food manufacturing supply chain is to deliver safe products to the right place at the right time in the right quantities to maximize customer service and maintain margin growth. The major areas of the supply chain that impact food safety and supply chain effectiveness go hand in hand. If products are not delivered on time profits fall. If products jeopardize consumer safety, nothing else will matter as the business will be at greater risk.
To succeed, Food Safety Supply Chain Management must occur. This combines the management of supply chain and the awareness of food safety into the same process. The complicated functions of the major roles of purchasing, manufacturing and distribution are collaborative process that focuses on profitable on time delivery as well as food safety at every step. This ensures that the transition from one step to another is seamless and the links do not break causing food safety and supply chain risk.
Supply chain transparency is a necessity as consumers and regulators increase the pressure for safe products and for up to the minute information on a products life cycle from field to fork. Supply chain visibility and traceability allows companies to know where each ingredient and component originated and where each finished product is heading. Start to finish visibility is critical to profitable and safe supply chains and vital to if food safety is jeopardized and recalls are required.
The supply chain today has many players from supplier, farmer, manufacturer, transporter, distributor and seller. These players and their functions must be strategically managed both separately and collectively to minimize risks and provide a continuous unbroken supply chain.
In today’s technology rich marketplace, tools exist to improve this process and more are coming. The visibility and the data provided by IoT solutions allow organizations to significantly reduce supply chain risk by having the correct procedures in place to minimize breaches in food integrity. Lack of end to end supply chain visibility can lead to food safety failures that can result in damaging companies brand reputation, bottom line and ethical responsibility to the public.
Food safety challenges will continue to pressure food manufacturers as supply chain complexity grows and consumer preferences evolve. Manufacturers need to understand that with new and innovative processes and solutions such as Blockchain, the Internet of Things, Machine Learning and others synchronizing the supply chain while maintaining food safety is an achievable goal.
About the author: Stephen Dombroski is the senior marketing manager of food and beverage markets at QAD Inc. in Santa Barbara, CA. QAD is a provider of of enterprise resource planning (ERP) software. The company provides services to global manufacturing companies. Dombroski has worked in the food safety and manufacturing industry for three decades. | <urn:uuid:021b31fd-7f33-45bf-a5b9-57cbd20b1d87> | CC-MAIN-2022-33 | https://www.foodsafetynews.com/2017/12/keep-the-links-in-supply-chain-connected-to-boost-food-safety/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.944671 | 1,772 | 3.078125 | 3 |
Top Tourist Attractions in Michigan
Tourist attractions from Detroit to the state's beautiful landscapes, there are a lot of things to see! People who are interested in Nature will find that the Great Lakes coastline offers unique opportunities to enjoy dunes & shorelines not found close by the ocean.
Many people enjoy visiting historical sites. One of the most popular places to visit is Fort Mackinac on Mackinac Island and Greenfield Village, which is part of the Henry Ford historic site.
Those looking for a faster pace, Detroit is an excellent place to visit. It has worked hard to embrace its contributions as the motor city and evolved into a top tourist destination and cultural center.
From the bright lights of a city to the Great Lakes, there are more things to see and do in Michigan with our list of attractions for tourists.
Michigan's Sleeping Bear Dunes National Lakeshore is a 35 mile long park and spans two islands in Lake Michigan.
The Park was created with its variety of natural features, including forests, beaches, dune formations and glacial phenomena in mind.
Sleeping Bear Dunes National Lakeshore includes many cultural features like an 1871 lighthouse, three former Life-Saving Service/Coast Guard stations and an extensive rural historic farm district.
The Lakeshore offers a range of activities suitable for every age. You can climb the sand dunes, go swim on one of the beaches, or take a walk through the beech/maple forest to one of our many scenic overlooks.
Maybe you would like to spend some time at the museums to learn a little bit about the history and culture of this place. The Sleeping Bear Heritage Trail offers you over four miles of paved trails for you to explore.
Mackinac Island has remained untouched by time. It is the only theme park in America which is not powered by transport vehicles - it relies on its visitors' abilities to travel on foot, horseback or as a passenger. Surrounded by water, it has been able to avoid major changes like the arrival of cars and bikes.
The small, permanent population of 500 and summer residents keep the original Victorian image preserved and enhanced.
Mackinac Island State Park's natural beauty is perfect for all. Families and children alike love the opportunity to explore a new environment that features world-famous historic landmarks.
Mackinac Island is famous for its Lilac Festival which celebrates the color & fragrance of the Isle's trademark flower. It's a major tourist attraction that culminates with one of the largest "All Horse Hitch" parades in North America. The American Bus Association has designated this event as one of the nation's top 10 attractions.
The residents are quite friendly and welcoming. Best time to visit is during the winter holiday or cross-country season. Prices do go down in the cold seasons, but there's always a warm atmosphere that you won't find anywhere else.
When you step off of the Island Ferry Dock, you will be in a living Victorian Village. Please cross streets on straight angles rather than diagonally and be aware of street traffic. You will also see a lot of horses, bikes and people coming and going in carriages. Enjoy all that this area has to offer while staying safe!
Summers on the island are typically calm, with mild mornings and warmer afternoons. It is suggested to dress comfortably in layers as it can change throughout the day. During the evening, sweaters can be put back on in order to stay warm through the night.
Winters in the Midwestern US are interestingly cold and by February, the Straits freeze and Lake Huron is covered with ice.
The average temperatures vary throughout the year while the winter holidays and cross-country skiing season occur in the month of December.
The Detroit Institute of Arts is an art museum in Detroit, Michigan that features paintings from artists including Dutch, Flemish, and Italian artists in its large collection. It holds more than of artwork and is one of the best-known museums in the United States.
This museum contains a large collection of ancient and Islamic arts based on works acquired by Frederick Stearns, the pharmaceutical magnate. Ancient Greek, Roman, Egyptian, and ancient Persian holdings have been augmented by artifacts from western Europe and ancient Arabia. The Frederick Stearns Collection also houses a large collection of ancient Greek and Roman objects, including ancient Egyptian artifacts, as well as an extensive range of Islamic art. It is among the oldest and most comprehensive in North America.
The museum houses works from many cultures through time, including Asian, African, Oceanian, and Native American arts. The museum also has modern works from artists around the world.
The Detroit Museum of Art was founded in 1885 by a group of Detroit citizens. In 1919, it was given to the city and moved into its present Neoclassical-style structure. The building was enlarged by additions completed in 1966 and 1971.
The MHT's central courtyard is decorated with 27 murals by Mexican painter Diego Rivera that depict the automobile industry. The General Motors Center for African American Art was formed in 2001, followed by the new department to help spread out culture and sharing of resources among others.
Frederik Meijer Gardens & Sculpture Park has various environments such as the outdoor courts and Japanese wood garden that would be enjoyed by art lovers. Their gardens are a great place to re-energize and relax. They offer different outdoor landscapes in addition to the traditional landscaped garden, a children's garden, and "Butterfly Maze." Their Japanese Garden offers two water falls that provide the perfect contrast with its peaceful nature.
The 1880s farmhouse is a replica of Lena Meijer's first home and includes the Farm Garden. The Lena Meijer Conservatory is a five-story tropical environment that houses many rare and exotic plants, and in March and April, visitors can watch the amazing process of Monarch butterflies transforming from caterpillar to delicate insect. Sculptures are found throughout both indoor and outdoor spaces.
The Henry Ford consists of three attractions: a museum, an auto-museum, and a history center. "The Henry Ford" explores life and work of the auto-industry icon as well as American innovation from 1800 to present day. You will be able to step back in time while visiting historic Greenfield Village. It is a living history museum that offers what life was like in the 19th century.
There are many points of interest including working farms, a restaurant serving traditional fare from the 1830s, the depot where you can catch a train on a steam-powered locomotive and even rides in a Model T. Henry Ford Museum of American Innovation tells the story of inventors and forward-thinkers who helped shape the world we see today, from the Wright brothers' dream to fly to Rosa Parks' conviction.
For a look at the most recent inventions and innovations, visit the Ford Rouge Factory Tour. Regardless of work preferences, this tour is sure to be intriguing.
6. Detroit Zoo
The Detroit Zoo has animals all over the world and allows you to experience different ecosystems. From African animals in the forest or grassland, to many family favorites including aardvark and zebra - it's always an innovative zoo adventure
The zoo's famous polar bears live in an arctic habitat where they share territory with six jaguars, 50 Canadian and American black bears, five seals, and some salmon. The Australian Outback is home to sixteen resident kangaroos and wallabies. The exotic Asian Forest has lots of amazing animals, such as red pandas and Amur tigers. The North American habitats feature some of the continent's most interesting animals, including bears, wolverines, and bald eagles.
Visitors can tour the zoo on the Tauber Family Railroad, which has been in operation since 1931. It has been hosting guests to help appreciate nature and art for many years. The island also houses reptile and amphibian centers, an aviary, and even a fine art collection.
Belle Isle tourist attraction is an island in the Detroit River that contains a park filled with numerous attractions, as well as a public entrance fee to enter.
Most family favorites to visit are the Belle Isle Aquarium, housed in a historic 1904 building with a stunning green opalite vaulted ceiling and including resident favorites like pufferfish, clown fish, turtles & more.
Another popular attraction, the Anna Scrips Whitcomb Conservatory has occupied 13 acres beside the Lilu Pond and Formal Gardens for over two hundred years. It is one of the oldest conservatories in the country, and extends from The Show House, into The Palm House, Cactus House, & Tropic House.
To learn more about the region's maritime history, visit the Dossin Great Lakes Museum & Science Center. This museum displays permanent and changing exhibits that celebrate the importance of these waters.
Among the many other attractions on Belle Isle are the grand James Scott Memorial Fountain, a Giant Slide, a Boat House, and the Belle Isle Golf Range.
Please call Superior Compounding Pharmacy in Plymouth Michigan to speak with one of our licensed pharmacists today at 734-404-6065. We can help answer any medication questions that you may have before traveling. | <urn:uuid:89ba4e9a-1a9b-4731-a340-98a7e6b38fb3> | CC-MAIN-2022-33 | https://www.superiorcompounding.com/health-news/health-news/top-7-rated-tourist-attractions-in-michigan/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.958227 | 1,910 | 1.90625 | 2 |
- Here are 3 places to be more intentional about the words you use from the platform and in your everyday life.
What you say is important. I’m pretty sure that God designed it to be that way. The books of Genesis and John both speak about some very important words that God used. We see that Jesus is the Word of God. (John 1:1-5). God’s Words created the world in which we live. He spoke—and it came into existence out of nothing. God’s Words create life. Jesus used His Words to heal, to forgive, to preach, and to save. He is the Word and His words changed eternity. The Bible is God’s Word to us. And prophets in the Old Testament would receive and share a Word from the Lord. If God used words in such important aspects of the life He gave us, then we can be pretty sure that God places a lot of importance on words. What we say matters.
We’ve all had times when we fumbled for words, said the wrong thing, sounded tacky, or unintentionally hurt someone’s feelings. We make mistakes. And we make mistakes with our words. But it’s time for the Church, church leaders, and everyone who associates with the body of Christ, to strongly consider the importance of their words and the effect those words have on others around them. We need to be intentional with our words. It matters.
1. Person-first Wording.
As a church, if we are striving to be inclusive in our worship services and in our churches (and if we’re not, why aren’t we?), then we need to look at the words we use in reference to those in our ministry. Specifically, person-first wording should infiltrate all of our speech patterns. Person-first wording means we put the person ahead of the adjective we are using to describe them because the person is more important than their challenges, roles, or functions. So rather than calling people an autistic person, a foster kid, or a cancer patient, we need to turn those words around. Instead, if you must use specific descriptors, you would say you were meeting with a person who has autism, assisting a child who is in (foster) care, and visiting a person who has cancer. Always put the person first, because they are much more than their challenges. It may seem trivial to you, but it means a lot to choose to see the person over their pain or even their role in ministry.
2. Gender-neutral Wording.
This can be a pretty controversial topic, and as a woman in ministry, I have pretty strong opinions after spending several years in seminary researching women’s roles in society, family, and ministry. I believe in equality for men and women. I believe that Jesus redeemed women’s place in society. Whether you are in agreement with those statements or not, it is still worth the Church’s time and effort to examine the language used referring to men and women. This is not about changing the Bible. This is about changing what we as leaders or church members say and what we sing. If we believe in equality for men and women, we need to show it in our language, including important, long-standing traditions in the church. And that may mean adapting our songs and even our favorite hymns and liturgy. Will this stir up trouble? Perhaps. Is it important? Definitely. Jesus demonstrated hospitality and kindness to women in a time when this was seen as controversial and punishable. Sometimes we have to be willing to tackle the hard topics to include everyone that Jesus included.
A great example of this is the Christmas carol, “Good Christian Men Rejoice.” Obviously, this hymn isn’t putting women down, but it does exclude them. The United Methodist Hymnal has done a great job of adapting this hymn to include women by changing it to, “Good Christian Friends Rejoice.” The change does not affect the rhythm or pentameter of the hymn; it fits in quite smoothly and does not exclude half of the congregation. This minor change does not reflect a church’s leaning towards egalitarianism, complementarianism, or traditionalism, and it might seem trivial to someone who has grown up singing the original version. But if we want to show real love for women the way Jesus did, we need to remember that our words matter. It is not enough to say that it is understood that the word mankind means the same as the word humankind. We need to make the change and honor both genders that God created with all of our language.
3. Private and Public Words.
We need to take a good, hard look at the words we use both in front of the congregation and behind closed doors. Do our words reveal integrity, are they in line with Scripture, and do they speak love and life? Or have our office conversations sneakily degraded into gossip and hurtful sarcasm? Are our prayer requests just an excuse to talk about other people’s problems? Does our language exclude a person or a people? We need to look at both the content of our words and the syntax of our words. What are we saying to and about the children in our church? We may not realize that referring to “those kids” has a much more negative connotation than talking to “our church’s children.” Does our grammar show what we really mean? And would God be pleased with those words? What about ethnic groups? Speaking in stereotypes isn’t helpful. In fact, it just reveals our unnoticed racial biases, which are always wrong. Our words matter and they often, even if unintentionally, reveal the condition of our hearts.
The Bible says that out of the overflow of the heart, the mouth speaks (Luke 6:45). Small changes in our vocabulary, minor changes in our songs, and adjustments to our speech patterns take a little bit of effort, but that effort will speak volumes about our love for the people that God has placed in our care. As we incorporate these changes in our speech, they will imprint on our hearts.
Is it on your heart to make sure that everyone feels welcome in your worship services? Does your congregation know that you truly value everyone? Ask God to point out to you ways in which your language might be hurtful rather than helpful. Be intentional as you sing, speak, and write, and make each word an effort to impart life, love, and hope into another person’s life. It matters.
Amanda is a toddler-chasing, coffee drinking, fashion boot-wearing, Fit-bit addicted, Jesus-loving, wife and mom to 6 small children. She spends her free time absorbed in fashion and tattoos, watching Pirates of the Caribbean, Googling, attempting clean eating, all while spreading autism awareness, encouraging adoption and foster care, championing the underdog, and of course, juicing. Amanda serves the local church as a licensed American Baptist pastor, worship leader, and free-lance writer. She holds a Master of Divinity from Liberty Baptist Theological Seminary, a Bachelor of Arts in Church Music from Eastern University, and a cosmetology license from Metro Beauty Academy. Her favorite places to be are the local zoo, the church piano bench, Facebook, and anywhere her family is. Catch up with Amanda at thebeautifulblog.com and twitter.com/beautifulmanda.
What's Your Reaction?
Over the last 30 years, Worship Leader Magazine has been blessed to have many different contributors on the editorial team - this is their archive. | <urn:uuid:bb10806e-4113-41bf-8aad-cf437fdea640> | CC-MAIN-2022-33 | https://worshipleader.com/discipleship/your-words-matter/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.962454 | 1,584 | 2.015625 | 2 |
Today, once again Prime Minister Narendra Modi addressed the Nation. In this address to the Nation Prime Minister talks about various topics such as, Self Reliant India, “Aatm Nirbhar Bharat“, Economic Package, Lockdown 4.0 etc.
Here’s is the 4 Takeaways from PM Narendra Modi addressed to Nation
1. Self Reliant:- PM talks about self Reliant india. He said, “Today when the entire world is in crisis, we will have to make India Self Reliant”.
When India speaks of self-reliance, it does not advocate for a self-centered system. In India’s self-reliance there is a concern for the whole world’s happiness, cooperation & peace: PM Narendra Modi
He said, “When the crisis started then not even a single PPE kit was manufactured in India, only a few N95 masks were available. Today 2 Lakh PPE kits and 2 Lakh N95 masks are manufactured in India daily”,
“In a world that is fighting life & death, India’s medicines today bring a new hope. With these steps, when India is being praised everywhere in the world, every Indian feels proud”.
2. Economic Package:- PM announced a special economic package 20 Lakh crore. He said, “This will play an important role in the Atmanirbhar Bharat Abhiyan”.
The announcements made by the government over Coronavirus, tge amount includes RBI earlier package and Government today’s package totals to Rs 20 Lakh Crores, which is around 10% of country’s GDP.
Finance Minister Nirmala Sitharaman will slowly announce the details of the Economic Package from tomorrow.
3. Lockdown 4.0:- PM also informed citizens about Lockdown 4.0 which will come in effect from 18 May 2020.
He said, “Scientists say that Corona will be a part of our lives for a very long time. But we can’t let our lives remain confined around Corona. We will wear masks and maintain social distancing but we will not let it affect us. So lockdown 4 will be in a new form with new rules”.
He confirms that Lockdown 4.0 will be based on the suggestions by states, information related to lockdown 4 will be provided before 18 May 2020.
He further said, “We had never seen or heard about such a crisis ever before. This is definitely unimaginable for mankind. This was unprecedented. But humanity will not accept defeat from this virus. We have to not only protect ourselves but also move forward”.
4. Importance of Local:- PM has also talks about the importance of Local in the society at these tough times. He said, “be vocal about local”.
Time has taught us that we must make ‘local’ the mantra of our lives. Global brands that are there today were once local too but when people there started supporting them they became global. That is why from today, every Indian must become vocal for our local: PM Modi | <urn:uuid:0fca975a-7718-4222-bb36-ed49f7dc3c37> | CC-MAIN-2022-33 | https://infotonline.com/4-takeaways-from-narendra-modi-speech/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.954493 | 656 | 1.507813 | 2 |
One of New Zealand's longest-serving prisoners has lost an appeal to allow inmates to vote behind bars.
Arthur William Taylor, who has spent about 40 years of his life in prison, and prisoners Hinemanu Ngaronoa and Sandra Wilde - brought their cases to the Court of Appeal, arguing it was discriminatory to ban prisoners from voting.
The case was originally taken in 2013 by Taylor - a self-described "jailhouse lawyer". He also sought and won a "declaration of inconsistency" in the High Court, saying a broad-sweeping ban on prisoners' voting was an unjustified limitation on the right to vote. That decision was upheld on appeal this year, but does not mean Parliament must repeal the ban.
A 2010 law extended a ban on prisoners voting to cover all prisoners. Previously it only applied to those jailed for more than three years.
However, the Court of Appeal today dismissed Taylor, Ngaronoa and Wilde's two appeals, in which they argued the 2010 ban was inconsistent with rules laid out in the Bill of Rights - and in particular that is was discriminatory towards Maori, who are disproportionately represented in prison.
The Court of Appeal judges said Maori and non-Maori prisoners were "treated the same way".
"Neither can vote. The policy does not have the effect, directly or indirectly, of treating the two groups differently," they ruled.
"If [the ban] is discriminatory under the Bill of Rights because the disproportionate representation of Maori in prisons means that they will be disproportionately disadvantaged, the same will apply to all prison policies that have a negative effect on prisoners' lives.
"Maori prisoners are not deprived of something that other prisoners can enjoy. Further, other groups in addition to Maori are overrepresented in prisons," they said - such as men and young people.
The proportion of Maori in prison was less than 1 per cent of the Maori population, the judges said - the same as with the non-Maori population, and therefore "so small that there is no material disadvantage".
Overall, the judges concluded that the ban did not directly or indirectly breach any of the provisions in the Bill of Rights, and dismissed the appeals.
Taylor, who has been denied parole 18 times, became infamous in 1998 after he escaped from the maximum security prison at Paremoremo north of Auckland with three others, including double murderer Graeme Burton.
The group made their way to Coromandel, where they hunkered down in luxury holiday homes and the bush to evade authorities.
He is serving a 17-year jail sentence for serious violence and drug-related crimes.
In recent years he has been in the headlines for his role as a "jailhouse lawyer", taking a number of legal actions against the Department of Corrections, including challenging the legality of the prison smoking ban and inmates' voting rights. | <urn:uuid:2a97ee65-54a4-4faa-b315-2d95240b2130> | CC-MAIN-2022-33 | https://www.nzherald.co.nz/nz/jailhouse-lawyer-arthur-taylor-loses-appeal-to-allow-prisoners-to-vote/4GPRSDWAUDW6T6OPJS5Z2AUCT4/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.977272 | 588 | 2.25 | 2 |
Fiat 132 1800 S Automatic, 1973
Fiat 132 1800 Special Automatic, year 1973. Colour dark blue combined with a red leatherette interior and red carpet. Red protective mats. This beautiful and quite rare Fiat 132 1800 S automatic was sold new in Rome Italy to Rolando Filipetti, the personal chauffeur of prime minister Giulio Andreotti. The car comes with many memorabilia of this relationship; A retirement farewell letter signed by Andreotti, Christmas card and a signed photo. Also, historic documents, and the original owner’s manual are present. Before the car was exported to the Netherlands in 2018, the car was given extensive service in Italy (September 2018). Amongst others, the radiator was renewed, as were the fluids, hoses, and tyres. The car was given new paint in the past, this was done professionally and properly. The car shows all the original details, and the original interior is fully original and in immaculate condition. This Fiat is in a particularly good to excellent condition, you will find only slight traces of previous use in the interior, and some minor imperfections like a paint-chip off the passenger door, a small spot of corrosion on the lower part of the right wing and two missing ‘plastic head’ screws in the rear lamp covers. The mechanicals function perfectly, the engine runs smoothly, and the automatic gearbox shifts accurately. The odometer currently shows 06.243 kilometres. It is realistic to assume that the car has driven 106.243 kilometres from new considering the wonderful all-over condition. This is a rare Fiat 132 1800 S Automatic with a 1970s Italian governmental connection close to the prime minister. You will be hard pressed to find a better-preserved example.
ARCHIVES | SOLD
The fiat 132 was introduced in May 1972, being the successor of the Fiat 125. With the larger 132 Fiat expanded their programme upward. The 123 featured a new clear styling in the best post war Fiat traditions, up-rated suspension and steering, and advanced twin cam engines which were derived from the 124 Sport. The Fiat 132 was available with all the luxury imaginable in the 1970s: automatic gearbox, air-conditioning, heated rear window, metallic paint, and alloy wheels. The Fiat 132 was available with 1600 and 1800 engines. The Fiat 132 Special was the first Fiat production saloon featuring an external rear view mirror!
Four cylinder in-line engine
twin camshafts (DOHC)
induction: twin choke carburettor
cylinder capacity: 1755 cc
capacity: 105 DIN bhp at 6000 rpm
top- speed: 106 mph – 170 km / h
gearbox: 5-speed manual or 3-speed automatic
brakes: servo assisted disk brakes on all wheels
weight: 1070 kg (manual), 1060 kg (automatic) | <urn:uuid:cf698b2a-240d-44f3-b697-feee2e244bee> | CC-MAIN-2022-33 | https://www.classicargarage.com/cars-for-sale/fiat-132-1800-s-automatic-1973 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.931313 | 596 | 1.726563 | 2 |
Relihan: Heat won't let up until next week
NWS in Topeka issues heat advisory until 8 p.m. Friday
The National Weather Service in Topeka has issued a heat advisory from noon until 8 p.m. Friday.
A heat advisory is issued when high humidities are expected to combine with hot temperatures to make it feel like it is 105 degrees or greater, according to the NWS.
It will continue to be hot through the weekend with only slight chances for rain before Monday, said 580 WIBW meteorologist Dave Relihan.
Highs Friday through Sunday will range from the uppers 90s to just over 100 degrees.
“The heat index most late afternoons will be running in the 104 to 108 range,” Relihan said. “There will be slight chances for showers and a few thunderstorms mainly in far northern Kansas tonight and again late Sunday. A very slight chance for showers and a few thundershowers will be present Monday morning generally along and north of I-70. Highs Monday will top out in the mid-90s.”
Tuesday will be partly cloudy and hot with highs in the mid-to upper 90s.
“Showers and thunderstorms appear more likely Tuesday night into Wednesday with the arrival and passage of a cold front,” Relihan said. “Highs on Wednesday will be in the lower 80s. Dry and milder weather will be with us for the end of next with highs in the mid- to upper 80s.”
Take extra precautions if you work or spend time outside, the NWS said. When possible, reschedule strenuous activities to early morning or evening hours. Wear light and loose-fitting clothing and rink plenty of water. | <urn:uuid:c8dc68d7-fe74-4bcf-a4b8-0f6cb98263d3> | CC-MAIN-2022-33 | https://www.cjonline.com/story/news/local/2014/08/22/relihan-heat-wont-let-until-next-week/16658985007/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.942441 | 370 | 1.5625 | 2 |
Oil and gas revenues added more than $1.7 billion to New Mexico coffers in the first four months of the year — more than in any other four-month period in state history.
A lot more.
Records compiled by the New Mexico Tax and Revenue Department show that year-on-year, revenues from January through April more than doubled from $782 million in 2021 — itself a record year. (Records lag by two months to allow producers time to report their production numbers.) This money gusher comes from increasing production in New Mexico’s portion of the Permian Basin — currently, the most productive oilfield on the planet — and skyrocketing oil and gas prices brought on by the Russian invasion of Ukraine.
State Sen. George Muñoz (D-Gallup), vice chair of the powerful Legislative Finance Committee, says that committee economists peg the state’s likely take from oil and gas at $5.2 billion for the fiscal year — roughly a billion more than last year’s oil and gas revenue. That tally may rise if world oil prices remain high.
Mountains of money are generally a good thing for anyone, but the unplanned windfall does come with complications. The first is the kind of money brought in by oil and gas production. Roughly speaking, state government views revenues in two ways: as one-time or recurring income. Recurring money remains fairly steady year after year. For example, people will generally remain employed and use their earnings to buy things, making income and sales taxes a reliable source of steady, recurring revenue for the state.
Source: Capital & Main
If you have further questions about the topic of New Mexico oil and Gas, feel free to contact us here. | <urn:uuid:623ecaf6-a8c5-4747-9f7a-48a8acdbf1b4> | CC-MAIN-2022-33 | https://www.rangerminerals.com/new-mexico-oil-and-gas-revenues-are-breaking-records-and-complicating-budgets/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.961348 | 357 | 2.171875 | 2 |
7. Seasonal scheme of Biological clock of the Earth
Let's divide Biological clock of the Earth into the sectors of seasons and
off-seasons. There are eight such sectors in Bioclock. And that is how they
We choose the basic points on the scheme (fig. 12). Those for seasons
will be: summer solstice day - June 22, 12:00; winter solstice day - December
22, 00:00; spring equinox day - March 22, 18:00; autumn equinox day - September
22, 6:00. A symmetry axis in Bioclock of the Earth will be a line connecting
the days of a summer solstice and a winter solstice, as exactly such line divides
amount of Light in the left and right halfs of Bioclock in equal parts.
And now we shall find the points of calendar borders of the seasons. For
this purpose let`s lay off 45 degrees (days) from the shown above basic points
to the both sides of the annual ecliptic because the calendar season duration
is 90 days, and we shall get the points of calendar borders of seasons: May
6, 15:00, August 6, 9:00; November 6, 3:00; February 6, 21:00. But the seasons
can be differentiated by these dates only in a calendar. In the Nature they
smoothly change into each other, forming the transitive periods, so-called off-seasons.
Having found the borders of off-seasons, we shall establish the true, but not
calendar borders of seasons. We shall make the following to determine the borders
of off-seasons. The duration of four off-seasons should be equal in sum to one
season. And, thus, 360 days of year should be divided not into four seasons,
but into 5 (fifth season is the sum of four off-seasons) and the duration of
one season will be identical to the sums of four off-seasons and will amount
72 days. And the duration of one off-season will be 72:4 =18 days. Having laid
off 9 days to the both sides of the annual ecliptic from points designating
calendar borders of seasons, we shall get the approximate biological borders
of the seasons and off-seasons.
Consequently, we have the following: winter-spring off-season - from January
27 till February 15; spring-summer off-season - from April 27 till May 15; summer-autumn
off-season - from July 27 till August 15; autumn-winter off-season - from October
27 till November 15.
Borders of seasons: winter - from November 15 till January 27; spring - from
February 15 till April 27; summer - from May 15 till July 27; autumn - from
August 15 till October 27.
Having connected with lines the annual ecliptic points, designating the biological
borders of the seasons and off-seasons, and laying from each other at the angle
of 180 degrees, we shall divide Biological clock of the Earth into eight sectors,
four of which will be represented by seasons, and four - by off-seasons. We
shall number them further. | <urn:uuid:e1c5d1e8-a30a-4100-885f-024bc5f88acc> | CC-MAIN-2022-33 | https://h-longevity.net/c07m2t1.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571502.25/warc/CC-MAIN-20220811194507-20220811224507-00065.warc.gz | en | 0.935172 | 701 | 3.71875 | 4 |
WASHINGTON -- President Barack Obama's financial overhaul law is nearly a year old. For congressional Republicans, the fight to weaken it is just starting.
Wary of trying to repeal the entire statute and being portrayed as Wall Street's protectors -- banks rank among the country's least popular institutions -- GOP lawmakers are trying to nibble away at the behemoth measure. It's a crusade they've waged all year, despite lacking the White House and Senate control they need to prevail.
Days ago, one Republican-run House committee approved bills diluting parts of the law requiring reports on corporate salaries and exempting some investment advisers from registering with the Securities and Exchange Commission. Another House panel voted to slice $200 million from Obama's $1.4 billion budget request for the SEC, which has a major enforcement role.
Meanwhile, Senate Republicans are continuing a procedural blockade that has helped prevent Obama from putting Elizabeth Warren or anyone else in charge of the Consumer Financial Protection Bureau, which opens its doors in two weeks.
The law hurts "the formation of capital, the cost of capital and access to capital, and you can't have capitalism without capital," said Rep. Jeb Hensarling, R-Texas, a leader of the House Financial Services Committee. "So Republicans in the House will be examining each and every one of the 2,000-plus pages" of the law, which he called "a job creator's nightmare."
Confident that Obama and the Democratic-controlled Senate can prevent the House from doing major damage, Democrats view the Republican drive as a political exercise -- for now.
"It's mostly setting a marker for the election. And it helps with their campaign contributions," said Rep. Barney Frank, D-Mass., who chaired the Financial Services Committee last year and was a chief author of the law. "But it also tells people in the financial community that if they win the next election, they'll be able to undo it all."
The financial industry leans Republican in its campaign contributions but not overwhelmingly. Sixty-one percent of the $9 million that commercial banks gave federal candidates for the 2010 elections went to Republicans, while 54 percent of the securities and investment industry's $9 million went to Democrats, according to the nonpartisan Center for Responsive Politics.
Democrats are using the GOP drive for their own fundraising.
In one email sent last week under Frank's name soliciting money for House candidates, the party wrote that Republicans want to "bring back the days of unrestrained excess, deception and de-regulation of Wall Street." The mailing called it "payback to their big contributors in the financial services industry."
Obama signed the banking and consumer protection measure last July 21, a keystone achievement that responded to the biggest financial crisis and most severe recession since the 1930s. It passed Congress with solid Democratic support and near-uniform GOP opposition.
Among its provisions, the law:
-- Created the consumer protection agency to oversee mortgages, credit cards and other financial products.
-- Established a body of regulators to scan the economy for threats to the financial system.
-- Required banks to hold back money for protection against losses.
-- Curbed the trading of derivatives, speculative investments partly blamed for the 2008 financial crisis.
-- Gave the Federal Reserve powers to oversee huge companies whose failures could jeopardize the entire financial system.
Yet the law was just a start, since it ordered federal agencies to craft rules to enforce it. As of July 1, out of an estimated 400 regulations to be written, 38 are complete. That leaves 362 proposed, facing a future deadline or having missed due dates for completion, according to the law firm Davis Polk.
Republicans say the overhaul went too far and has saddled banks and other companies with requirements that harm their competitiveness. The House Financial Services panel alone has held more than a dozen hearings on the law, in part to underscore to administration witnesses that some provisions -- like forcing banks to hold back capital as a hedge against losses -- will hurt business, according to the committee's chairman, Rep. Spencer Bachus, R-Ala.
"What we are doing is rational, it is sensible, it is entirely practical, it is compassionate," said Rep. Nan Hayworth, R-N.Y., a tea party-backed freshman on that panel. "So we are doing the right thing, and it behooves the Senate and the administration to follow suit."
The highest-profile fight has been over Warren, picked by Obama to set up the new consumer bureau. Many Democrats and liberal groups want her to become its first director.
Following a May clash between Warren and a House subcommittee chairman, House Oversight Committee Chairman Darrell Issa, R-Calif., plans to question the Harvard law professor and long-time consumer activist at a July 14 hearing about her role shaping the new agency.
Meanwhile, 44 GOP senators have promised to block a vote on any nominee unless the bureau is made "accountable to the American people" by replacing the director with a board of directors and giving Congress control over its budget. Forty-one senators can prevent a nomination from coming to a vote.
"You try to get leverage where you can. In the Senate, nominations are your leverage," said Mark A. Calabria, who monitors financial regulation at the conservative-leaning Cato Institute.
On another front, Republicans want to cut the budgets of agencies that are supposed to enforce the overhaul.
Besides denying the SEC extra money next year, the House Appropriations Committee would limit the consumer protection bureau to $200 million, well below the $329 million Obama wants. The full House has voted to hold the Commodity Futures Trading Commission, which oversees derivatives, to $171 million, short of this year's total and less than two-thirds of what Obama wanted.
Republicans cast the cuts as part of their deficit-cutting drive, but Democrats say the reductions are designed to obstruct the new law.
SEC Chairwoman Mary Schapiro said in a speech this spring that budget cuts would mean "an investor protection effort hobbled." | <urn:uuid:2a1bb175-c617-42f4-b77a-cb767a0d3b27> | CC-MAIN-2022-33 | https://www.foxnews.com/politics/gop-targets-financial-overhaul-law-for-revisions | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.958026 | 1,234 | 1.507813 | 2 |
Gamblin Relief Inks are formulated for all relief techniques, including woodblock, linocut, monotype and Solarplate. They contain the right amount of stiffness and tack to hold fine detail yet spread evenly on the block or plate. The palette of colors is designed to give artists intense pure pigmented colors straight from the jar, along with a wide range of color-mixing capabilities. Monotype printmaking, the most painterly of printmaking techniques, is very popular. While most painters and printmakers working in this process learn how to make any kind of ink work, the unique viscosity and tack of Gamblin Relief Inks makes them ideal for monotype printing processes. | <urn:uuid:80fc0b2c-4ba1-44cc-b13b-5368f87e0f19> | CC-MAIN-2022-33 | https://www.theblokdsm.com/products/relief-inks-gamblin | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.925674 | 142 | 1.734375 | 2 |
In China, the college entrance exam score is predictive for both firm success and wage-job success in the future, yet higher-score individuals are less likely to create firms.
In 2021, over 10.78 million Chinese high school students took the college entrance exam (Gaokao): a historical high. While the Gaokao is the most important talent selection channel in China, many questions about the Gaokao system remain unanswered. Does the exam measure ability? What type of ability? Does the exam score make a difference for a young person’s future career? Are higher-score individuals more likely to work in government, become entrepreneurs, or earn higher wages?
It is impossible to provide comprehensive answers to all of these questions in a single study, but here, we provide partial answers to some of these questions. Our results come from a recent study, motivated by a theoretical literature on talent allocation (e.g., Baumol 1990; Murphy, Shleifer and Vishny 1991; Acemoglu 1995). This literature has long noted that talent is general and can be used in both the entrepreneurial and non-entrepreneurial sectors, and that its allocation depends on the reward structure of a society. While this important theory of talent allocation has been developed for three decades, few empirical studies have directly tested it due to data challenges.
In Bai, Jia, Li and Wang (2021), we study whether talented Chinese are more or less likely to become entrepreneurs. Empirically, we link the universe of college admission records in 1999–2003 with the universe of Chinese firms and their owners, and then use a random sample of 20% of the linked data to examine who have become entrepreneurs and how successful their firms are. In total, this yields a sample of 1.8 million college graduates who created approximately 170,000 firms by 2015. We supplement this linked data with a large survey of Chinese college graduates that we conducted during 2010–2015 to study waged jobs. We use students’ Gaokao score as a proxy for talent and validate our measure with data.
Research design: within-college comparison
We focus on within-college analyses -- comparing individuals in their mid-30s with others in their cohort who graduated from the same college -- for conceptual and empirical reasons. Conceptually, the within-college comparison helps to control for the confounding factors of college reputation and network. Empirically, we find that most of the variation in firm creation comes from within colleges. For instance, although college fixed effects can explain up to 19% of the variation in wages of paid jobs (in our survey data), the effects can account for only 1.2% of the variation in firm creation. In addition, we find that the college fixed effects can explain only 46% of the variation in exam scores, leaving the majority of the variation to occur within colleges. The wide variation in scores within a college is driven by considerable uncertainty and political economy factors (particularly provincial quotas) in the college admission process. In addition, because Gaokao scores are comparable only for students from the same province and year, as well as the same academic track (social science vs. natural science), we isolate province-year-track fixed effects in our analyses.
We control for a set of individuals’ personal characteristics, which include gender, Hukou (rural vs. urban), high school quality, birth county’s GDP per capita, and age fixed effects. Although we do not have a specific measure of socioeconomic status (such as parental income), it is reasonable to assume that those from better high schools and wealthier counties have higher socioeconomic status. Within colleges, higher socioeconomic status is positively associated with exam scores.
Exam score, ability, and occupation choice
1. Given the same college, higher-score individuals are less likely to create firms by their mid-30s. A one-standard-deviation higher score is associated with a 10% lower probability of creating a firm. This finding holds even when we focus on the creation of more successful (large) firms, as shown in Figure 1 below:
Figure 1: College Entrance Exam Score and Firm Creation
Notes: Firm=I(Capital≥2M/15M) refers to defining a firm only if it is large, i.e., its registered capital no less than RMB 2 million/15 million.
We also find that individuals of higher socioeconomic status are more likely to create firms. This finding suggests that it is difficult for socioeconomic status to explain the negative relationship between the score and firm creation.
2. Opposite to the entrepreneurship result, the firms that are created by higher-score individuals are more successful than those of their lower-score counterparts. The firms created by higher-score individuals are typically larger, more likely to expand, more likely to enter non-local markets, more likely to survive, and more likely to be publicly listed. These results hold even when we address potential entry bias by using within-college peer exposure to predict entry. These results suggest that talent, as measured by the Gaokao score, can be turned into entrepreneurial ability.
3. Outside of entrepreneurship, higher-score individuals also earn higher wages, obtain jobs that provide local Hukou, and are more likely to join the state sector. These findings imply that the Gaokao score is also positively associated with wage ability.
4. The negative score-entrepreneur correlation varies greatly by industries, according to state penetration (measured by the share of state investment in total investment by industry), Figure 2(a) plots the estimates by industry where the dependent variable is a dummy indicating entering a certain industry. The coefficients can be interpreted as “one standard deviation score is negatively associated with X% of the dependent variable”. We find wide variation across industries. For instance, the negative score-entrepreneur correlation in the construction industry is 15 times that in the IT industry.
Figure 2(b) plots the correlation between these estimates and state penetration, where we control for the influence of human capital (proxied by the average years of schooling of employees by industry). As shown, in industries with more state penetration, the negative relationship between the score and firm creation is stronger, which further illustrates the importance of the state in influencing career choices of talented individuals.
Figure 2: Score-Entrepreneur Relationships by Industry
Taken together, our results suggest that the Gaokao score is positively associated with both entrepreneurial ability and waged-job ability, but that higher-score individuals are attracted away by wage jobs, particularly those of the state sector.
Alternative hypotheses: Lower entrepreneurial ability? Personal traits?
In principle, however, there could exist two broad alternative hypotheses to explain why higher-score individuals are less likely to create firms. In the first alternative hypothesis, which we term the “lower entrepreneurial ability” hypothesis, the score does not measure a general talent that is useful for entrepreneurs; rather, it is negatively correlated with entrepreneurial ability, which could potentially explain the negative correlation between score and firm creation. For instance, one could assume that those with higher scores lack the skills of jack-of-all-trades (e.g., Lazear 2004) and/or that they obtain higher scores by putting more effort into the test, but their actual ability may be lower than that of their lower-score counterparts. Our evidence on firm success, however, goes against this hypothesis.
The second alternative hypothesis emphasizes that higher-score individuals possess unfavorable behavioral traits (e.g., more risk averse or less social) for becoming entrepreneurs, which we term the “personal traits” hypothesis. Using survey data, we find that, within any given college, higher-score individuals have a higher GPA and are more likely to receive academic awards. We do not, however, find strong correlations between scores and risk attitudes or participation in social activities. Overall, these results suggest that scores are not correlated with these behavioral traits in a way that is particularly unfavorable for becoming an entrepreneur.
Can we apply our findings to other countries? In principle, one can link individual-level SAT (or other exam) scores to firm creation and firm success in the United States or other countries, however, we are not aware of any such studies. In light of our findings on the importance of the state sector, however, we conjecture that there may be wide variation across countries, depending on the role of the state in the economy. We thus hope that our study provides new avenues for future research that allow scholars to compare talent allocation across countries.
(Chong-En Bai, School of Economics and Management, Tsinghua University; Ruixue Jia, University of California, San Diego, London School of Economics and Political Science and NBER; Hongbin Li, Stanford University; Xin Wang, Department of Economics, Chinese University of Hong Kong, Shatin, N.T., Hong Kong.)
Acemoglu Acemoglu, Daron (1995), “Reward Structures and the Allocation of Talent,” European Economic Review, 39(1): 17–33.
Bai, Chong-En, Ruixue Jia, Hongbin Li, and Xin Wang (2021), “Entrepreneurial Reluctance: Talent and Firm Creation in China,” NBER Working Paper 28865.
Baumol, William J., Robert E. Litan, and Carl J. Schramm (2007), Good Capitalism, Bad Capitalism, and the Economics of Growth and Prosperity. Yale University Press.
Lazear, Edward (2004), “Balanced Skills and Entrepreneurship,” American Economic Review, 94(2): 208–211.
Murphy, Kevin M., Andrei Shleifer, and Robert W. Vishny (1991), “The Allocation of Talent: Implications for Growth,” Quarterly Journal of Economics, 106(2): 503–530. | <urn:uuid:2ddd7dea-0e30-481c-baa1-30d2e78cf2c1> | CC-MAIN-2022-33 | https://voxchina.org/show-3-243.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.943137 | 2,044 | 2.34375 | 2 |
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A fayre russet coat the tanner had on
Marrye, heaven forfend, the tanner replyde, Fast buttoned under his chin;
That thou my prentise were: And under him a good cow-hide,
Thou woldstspend more good than I shold winn, And a mare of four shilling,
By fortye shilling a yere.
If thou wilt not seeme strange;
Thoughe my horse be better than thy mare, To weet what he will saye.
Yet with thee I faine wold change. God speede, God speede thee, said our king. Why if with me thou faine wilt change, Thou art welcome, sir, sayde hee.
As change full well maye wee, The readyest waye to Drayton Basset
By the faith of my bodye, thou proude fellowe, I praye thee to shewe tó mee.
I will have some boot of thee.
I sweare, so mote I thee :
And that thou well mayst see.
And softly she will fare:
Thy horse is unrulye and wild, I wiss; And I pray thee wend with mee.
Aye skipping here and theare.
Now tell me in this stounde.
But a noble in gold so rounde.
Sith thou wilt have it of mee.
I would have sworne now, quoth the tanner, And I will paye thy fare.
Thou hadst not had one penniè.
But since we two have made a change,
A change we must abide ;
Although ihou hast gotten Brocke my mare, Than thou hast pence in thine.
Thou gettest not my cowe-hide.
I will not have it, sayde the kynge,
I sweare, sò mote I thee;
Thy foule cowe-hide I would not beare, For he weende he had beene a thiefe.
If thou woldst give it mee.
The tanner he took his good cowe-hide, For the cloathes thou wearest upon thy backe
That of the cowe was hilt; Might beseeme a lord to weare.
And threwe it upon the king's saddèlle,
That was so fayrely gilte.
Now help me up, thou fine fellowe,
"Tis time that I were gone : And standeth in midds of thy goode.
When I come home to Gyllian iny wise, What tydings heare you, sayd the kynge,
She'll say I'm a gentilmon. As you ryde far and neare?
The kinge he took him by the legge; I hear no tydings, sir, by the masse,
The tanner a f*** let fall. But that cow-hides are deare.
Now marrye, good fellowe, said the kinge, Cowe-hides ! cowe-hides ! what things are
Thy courtesye is but small. those ?
When the tanner he was in the king's saddèlle, I marvell what they bee?
And his foote in the stirrup was, What, art thou a foole? the tanner reply'd;
He marvelled greatlye in his minde, I carry one under mee.
Whether it were golde or brass. What craftsman art thou? said the king;
But when his steede saw the cows-taile wagge, I pray thee tell me trowe.
And eke the black cowe-horne, I am a barker*, sir, by trade ;
He stamped, and stared, and awaye he ranne, Now tell me what art thou?
As the devill had him borne. I am a poore courtier, sir, quoth he,
The tanner he pulld, the tanner he sweat, That am forth of service worne;
And held by the pummil fast; And fain I wolde thy prentise bee,
At length the tanner came tumbling downe: Thy cunninge for to learne.
His necke he had well-nye brast. * Dealer in bark.
Take thy horse again with a vengeance, he sayd, Balow, my boy, thy mithers joy,
Thy father breides me great annoy;
It grieves me sair to see thee weipe. Yet if againe thou faine woldst change, When he began to court my luve, As change full well may wee,
And with his sugred words to muve, By the faith of thy bodye, thou jolly tanner, His faynings fals, and flattering cheire, I will have some boote of thee.
To me that time did not appeire: What boote wilt thou have, the tanner reply'd, But now I see, most crueli hee Nowe tell me in this stounde?
Cares neither for my babe nor mee. Noe pence, nor half-pence, sir, by my faye,
Balow, &c. But I will have twentye pounde.
Ly stil, my darlinge, sleipe a while, Here's twenty groates out of my purse;
And when thou wakest sweitly smile : And tweniye I have of thine :
But smile not, as thy father did, And I have one more, which we will spend To cozen maids; nay, God forbid ! Together at the Vine.
But yette I feire, thou wilt gae neire, The kinge set a bugle horne to his mouthe,
Thy fatheris hart and face to beire. And blewe bothe loude and shrille;
Balow, &c. And soone came lords, and soone came knights, I cannae chuse, but ever will Fast ryding over the hille.
Be luving to thy father stil: Nowe, out alas! the tanner he cryde,
Whair-eir he gae, whair-eir he ryde, That ever I sawe this daye!
My love with hiin maun still abýde; Thou art a strong thefe, yon come thy fellowes In weil or wae, whair-eir he gae, Will beare my cowe-hide away.
Mine hart can neir depart him frae.
Balow, &e. They are no thieves, the king replyde, I sweare, so mote I thee :
But doe not, doe not, prettie mine, But they are the lords of the north countrèy, To faynings fals thine hart incline : Here come to hunt with mee.
Be loyal to thy luver trew,
And nevir change hir for a new : And soone before our king they came,
If gude or faire, of hir have care, And knelt downe on the grounde:
For womens banning's wonderous sair. Then might the tanner have beene awaye,
Bolow, &c. He had lever than twentye pounde.
Bairne, sin thy cruel father is gane, A coller, a coller, here, sayd the kinge,
Thy winsome smiles maun eise my paine : A coller, he loud did crye.
My babe and I'll together live,
My babe and I right saft will ly,
Balow, &c. After a coller comes a halter,
Fareweil, fareweil, thou falsest youth, And I shall be hanged to-morrowe.
That ever kist a woman's mouth ! Away with thy feare, thou jolly tanner; I wish all maids be warn'd by mee,
For the sport thou hast shewn to mee, Nevir to trust man's curtesy ;
For if we doe bot chance to bow,
Balow, my babe, ly stil and sleipe !
It grieves ine sair to see thee weipe. "Tis worth three hundred markes by the yeare,
$117. Corydon's doleful knell. To maintain thy good cowe-hide.
The burthen of the song, Ding, Dong, &c. is at preGramercye, my liege, the tanner replyde, sent appropriated to burlesque subjects, and thereFor the favour thou hast me showne;
fore may excite only ludicrous ideas in a modern If ever thou comest to merry Tamworth, reader, but in the time of our poet it usually acNeates leather shall clout thy shoen.
companied the most solemn and mournful strains.
My Phillida, adieu, love! § 116. Lady Ann Bothwell's Lament. A For evermore farewell ! Scottish Song
Ay me! I've lost my true love, The subject of this pathetic ballad is, A lady of quality,
And thus I ring her knell. of the name of BOTHWELL, or rather BOSWELL,
Ding dong, ding dong, ding dong, baving been, together with her child, deserted by My Phillida is dead! her husband, or lover, composed these affecting
I'll stick a branch of willow lines herself.
At my fair Phillis' head.
Our bridal bed was made:
But 'stead of silkes so gay, Tby maining maks my heart ful sad.
She in her shroud is laid. Ding, &c. Her corpse shall be attended
With an old hall, hung about with pikes, guns, By maides in faire array,
and bows, Till 'th' obsequies are ended,
With old swords, and bucklers, that had borne And she is wrapt in clay.
Ding, &c. many shrewde blows, Her herse it shall be carried
And an old frize coat, to cover bis worship's By youths that do excel;
trunk hose, And when that she is buried,
And a cup of old sherry to comfort his copper I thus will ring her knell. Ding, &c.
Like an old courtier, &c. Dose, A garland shall be framed
With a good old fashion, when Christmasse By art and nature's skill,
was come, Of sundry-colour'd flowers,
To call in all his old neighbours with bagpipe In token of good will* ;
With good cheer enough to furnish every old And sundry-colour'd ribbands
And old liquor able to make a cat speak, and On it I will bestow;
man dumb; But chiefly blacke aud yellowe
Like an old courtier, &c. With her to grave shall go. Ding, &c.
With an old falconer, huntsman, and a kennel I'll deck her tomb with flowers,
of hounds, The rarest ever seen ;
That never hawked nor hunted but in his own And with my tears, as showers,
grounds, I'll keepe ihem fresh and green. Ding, &c. Who, like a wise man, kept himself within Instead of fairest colours,
his own bounds, Set forth with curious artt,
And when he dyed gave every child a thousand Her image shall be painted
good pounds: On my distressed heart. Ding, &c
Like an old courtier, &c. And thereon shall be graven
But to his eldest son his house and land he asHer epitaph so faire,
stifull mind, “ Here lies the loveliest maiden
Charging him in his will to keep the old boun“That e'er gave shepherd care.” Ding, &c. To be good to his old tenants, and to his neighIn sable will I mourne;
bours be kind : Blacke shall be all my weede :
But in the ensuing ditty you shall hear how he Ay me! I am forlorne,
was inclin'd, Now Phillida is dead.
Ding, &c. Like a young courtier of the king's,
And the king's young courtier. $ 118. The old and young Courtier.
Like a flourishing young gallant, newly come
to his land, The subject of this excellent old song is a comparison who keeps a brace of painted madams at his
between the manners of the old gentry as still subsisting in the times of Elizabeth, and the modern and takes up a thousand pound upon his fa
command, refinements affected by their sons in the reigns of
ther's land, her successors.
And gets drunk in a tavern, till he can neither An old song made by an aged old pate,
go nor stand! of an old worshipful gentleman who had a
Like a young courtier, &c. great estate, That kept a brave old house at a bountiful rate, with a new-fangled lady, that is dainty, nice, And an old porter to relieve the poor at his
gate; Who never knew what belonged to good Like an old courtier of the queen's, And the queen's old courtier.
house-keeping, or care; With an old ladywhose angerone word asswages;
Who buys gaudy-colour'd fans to play with
wanton air, They every quarter paid their old servants their wages,
And seven or eight different dressings of other
women's hair ; And never knew what belonged to coachman, footmen, nor pages,
Like a young courtier, &c. But kept twenty old fellows with blue coats and With a new-fashion'd hall, built where the Like an old courtier, &c.
old one stood, With an old study fill'd full of learned old books, Hung round with new pictures that do the With an old reverend chaplain, you might
poor no good, know him by his looks,
With a fine marble chimney, whereiu burns With an old buttery-hatch worn quite off the neither coal nor wood, hooks,
[zen old cooks; And a new smooth shovelboard, whereon no And an old kitchen that maintain'd half a do- victuals e'er stood; Like an old courtier, &c.
Like a young courtier, &c. • It is a custom in many parts of England, to carry a fine garland before the corpse of a woman who dies unmarried.
† This alludes to the painted effigies of alabaster anciently erected upon tombs and monuments:
With a new study stuft full of pamphlets and The cynic loves his poverty plays,
- (prays, The pelican her wilderness ; And a new chaplain, that swears faster than he And 'tis the Indian's pride to be With a new buttery-hatch that opens once in
Naked on frozen Caucasus : four or five days,
Contentment cannot smart; Stoics, we see; And a new French cook to devise fine kick- Make torments easie to their apathy.
shaws and toys;
These manicles upon my arm
I as my mistress' favours wear; With a new fashion, when Christmas is' draw
And, for to keep my ancles warm, ing on,
I have some iron shackles there : On a new journey to London straight we all These walls are but my garrison; this cell, must be gone,
Which men call jail, doth prove my citadel: And leave none to keep house, but our new porter John,
I'm in the cabinet lock'd
Or, like the great mogul or pope,
Am cloyster'd up from public sight: With a new gentleman-usher, whose carriage Retiredness is a piece of majesty, is complete,
And thus, proud Sultan, I'm as great as thee. With a new coachman, footmen, and pages to Here sin for want of food must starve, carry up the meat,
Where tempting objects are not seen; With a waiting gentlewoman, whose dressing
And these strong walls do only serve is very neat,
To keep vice out, and keep me in: Who, when her lady has din'd, lets the ser
Malice of late's grown charitable, sure;
I'm not committed, but ain kept secure.
So he that struck at Jason's life,
Thinking t' have made his purpose sure, For which sundry of his ancestors' old manors
By a malicious friendly knife, are sold;
shold, Did only wound him to a cure. And this is the course most of our new gallants Malice, I see, wants wit; for what is meant Which makes that good house-keeping is now Mischief, oftimes proves favour by th' event. grown so cold
When once my prince affliction hath,
Prosperity doth treason seem;
I can learn patience from him :
Now not to suffer, shows no loyal heart; This excellent old song is preserved in David Lloyd's When kings want case, subjects must beara part. * Memoires of those that suffered in the cause of
What thongh I cannot see my king, Charles I.” He speaks of it as the composition of
Neither in person or in coin; a worthy personage, who suffered deeply in those times, and was still living, with no other reward
Yet contemplation is a thing than the conscience of having suffered. The au- That renders what I have not mine : thor's name he has not mentioned; but, if tradition My king from me what adamant can part, may be credited, this song was written by Sir R. Whom I do wear engraven on my heart! L'ESTRANGE Beat on, proud billcws : Boreas, blow;
Hlave you not seen the nightingale,
A prisoner like, coopt in a cage;
Ilow doth she chant her wonted tale
In that her narrow hermitage!
Even then her charming melody doth prove Though surly Nereus frown, my thoughts are
That all licr bars are trecs, her cage a grove. calm; Then strike, A Miction, for thy wounds are bakın.
I am that bird, whom they combine • That which the world miscalls a jail,
Thus to deprive of liberty; A private closet is to me :
But though they do my corps confine, Whilst a good conscience is my bail,
Yct, mangre hate, my soul is free: And innocence my liberty ;
And though immur'd, yet can I chirp, and sing Locks, bars, and solitude, together met,
Disgrace to rebels, glory to my king!
My soul is free as ambient air,
Although my baser part's immew'd, As if their wisdoms had conspira
Whilst loyal thoughts do szill repair The salamander should be burn'd:
T' accompany my
solitude: Or like those sophists that would drown a fish, Although rebellion do my body binde, I am constrain d to suffer what I wish. My king alone can captivate my minde.
$ 120. To Althea from Prison. B. Why does she weep, thy bonny bonny bride? This excellent Sonnet, which possessed a high degree
Why does she weep, thy winsome marrow? of fame among the old Cavaliers, was written by And why dare ye nae mair
weil be seen Colonel Richard Lovelace during his confinement Puing the birks on the Braes of Yarrow? in the Gate-house, Westminster; to which he was committed by the House of Commons, in April 1642, A. Lang maun she weep, lang maun she, måun for presenting a petition from the county of Kent, requesting them to restore the king to his rights,
Lang maun she weep with dule and sorrow; and to settle the government. See Wood's Athenæ, And lang maun I nae mair weil be seen vol. ii. p. 228; where may be seen at large the af- Puing the birks on the Braes of Yarrow: fecting story of this elegant writer; who, after having
For she has tint her luver, luver dear, been distinguished for every gallant and polite ac
Her luver dear, the cause of sorrow; complishment, the pattern of bis own sex, and the darling of the ladies, died in the lowest wretchedness,
And I hae slain the comliest swain obscurity, and want, in 1658.
That eir pu'd birks on the Braes of Yarrow. When love with unconfined wings
Why rins thy stream, O Yarrow, Yarrow reid? Hovers within my gates,
Why on thy braes heard the voice of sorrow! And my divine Althea brings
And why yon melancholious weids To whisper at my grates ;
Hung on the bonny birks of Yattow? When I lye tangled in her haire,
What's yonder Aoats on the rueful, ruefal And feier'd with her eye,
Aude? The birds that wantop in the aire
What's yonder floats? Odule and sorrow! Kuow no such libertie.
O'tis he, the comely swain I slew When Rowing cups run swiftly round
Upon the duleful Braes of Yarrow! With no allaying Thames,
Wash, 0 wash his wounds, his wounds in Our carelesse heads with roses crown'd,
tears, Our hearts with loyal fames ;
His wounds in tears, with dule and sorrow, When thirsty griefe in wine we steepe,
And wrap his limbs in mourning weids, When healths and drafts goe free,
And lay him on the Braes of Yarrow! Fishes that tipple in the deepe,
Then build, then build, ye sisters, sisters sad, Know no such libertie.
Ye sisters sad, his tomb with sorrow; When, linnet-like, confined I
And weep around in waeful wise With shriller note shall sing
His hapless fate on the Braes of Yarrow. The mercye, sweetness, majestye, And glories, of my king;
Curse ye, curse ye, his useless, useless shield, When I shall voyce aloud how good
My arm that wrought the deed of sorrow,
The fatal spear that pierc'd his breast, He is, how great should be,
His comely breast on the Braes of Yarrow. Th' enlarged windes that curle the food Know no such libertie.
Did I not warn thee, not to, not to love?
And warn from fight? but, to my sorrow, Stone walls do not a prison make, Nor iron barres a cage;
Too rashly bauld, a stronger arm
Thou mett'st, and fell'st on the Braes of Minds innocent and quiet take
Sweet smells the birk, green grows, green
grows the grass, Angels alone, that soare above,
Yellow on Yarrow's banks the gowan, Enjoy such libertie.
Fair hangs the apple frae the rock,
Sweet the wave of Yarrow flowan.
Flows Yarrow sweet? as sweet, as sweet $ 121. The Braes of Yarrow, in Imitation of the ancient Scots Manner.
As green its grass, its gowan as yellow; Was written by William Hamilton of Bangour, As sweet smells on its braes the bírk,
Esq. who died March 25, 1754, aged 50. The apple frae its rock as mellow. A. Busk ye, busk ye, my bonny bonny bride, Fair was thy luve, fair, fair indeed thy love, Busk
busk ye, my winsome marrow, In Aow'ry bands thou didst him fetter; Busk busk ye, my bonny bonny bride, Though he was fair, and well beluv'd again,
And think nomair on the Braes of Yarrow. Than me he never lov'd thee better. B. Where gat ye that bonny bonny bride? Busk ye, then busk, my bonny bonny bride,
Where gat ye that winsome marrow? Busk ye, busk ye, my winsome marrow, A. I gat her where I dare na weil be seen, Busk ye,
and love me on the banks of Tweed, Puring the birks on the Braes of Yarrow. And think nae mairon the Braes of Yarrow. Weep not, werp not, iny bonny bonny bride! B. How can I busk a bonny bonny bride!
Weep not, weep not, my winsome marrow! How can I busk a winsome marrow? Nor let thy heart lainent to leive
How luve him upon the banks of Tweed, Puing the birks on the Braes of Yarrow. That slew my lave on the Braes of Yarrot | <urn:uuid:5d52690b-fc0a-4652-9a7a-3e399ea55bd4> | CC-MAIN-2022-33 | https://books.google.co.uk/books?id=bkpgTiet57EC&pg=PA994&vq=king&dq=editions:OXFORD600077009&lr=&hl=en&output=html_text | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.915722 | 5,615 | 2.078125 | 2 |
Background: In the era of integrated genomic-histologic analysis of brain tumors, new biomarkers have been introduced as diagnostic, prognostic, and therapeutic indicators. The analysis of the mutation in the isocitrate dehydrogenase (IDH) genes IDH1 and IDH2 has provided important diagnostic and prognostic information for patients affected by diffuse glioma (i.e., the presence of the mutation has been related to an increased survival rate). The reference standard of IDH mutation detection has been its assessment in surgical specimens, immunohistochemistry, and/or genetic sequencing. Knowing the IDH status information preoperatively would be of great importance, because it has been related to tumor progression and the response to treatment. The oncometabolite 2-hydroxyglutarate (2HG), accumulated in gliomas with IDH mutation status, can be detected in vivo using magnetic resonance spectroscopy (MRS). Methods: The 2HG-MRS technique remains technically challenging. We have summarized the results of the first pilot study in Australia, which included 10 patients affected by glioma. The data recorded from May 2017 to November 2018 were analyzed. Results: In our exploratory study, we reached a sensitivity and specificity of 100%, confirming the strong predictive role of 2HG, as detected using MRS, in the diagnosis of glioma. Conclusion: In the present study, we have focused on methodological tips and future perspectives of the technique in the neuroimaging and neuro-oncological scenario. We would advocate the integration of 2HG-MRS into standard clinical practice.
- Magnetic resonance spectroscopy
ASJC Scopus subject areas
- Clinical Neurology | <urn:uuid:6e7f6536-60b2-4c66-92c8-5ffffdd9d62c> | CC-MAIN-2022-33 | https://utsouthwestern.pure.elsevier.com/en/publications/magnetic-resonance-spectroscopic-assessment-of-isocitrate-dehydro | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.914374 | 387 | 1.640625 | 2 |
That’s one small snack for a man…
Astronauts could soon be feasting on freshly baked space cakes thanks to a prototype oven being developed for upcoming space missions by NASA.
The purpose built cooker is the work of NanoRacks in partnership with Zero G Kitchen, a company that creates appliances for microgravity use in long haul space flights.
It is believed that one of the very first aromas from the very first baked goods made in space could be chocolate chip cookies.
One thing that the developers of the space oven have yet to overcome is the effect zero gravity has on food. In space it is quite likely that the cookie won’t crumble but it could easily take on a cylindrical shape instead. | <urn:uuid:db539f32-8088-439d-a3c1-c339f8c8c1ca> | CC-MAIN-2022-33 | https://www.ukvending.co.uk/info/thats-one-small-snack-for-a-man | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.955362 | 150 | 2.59375 | 3 |
And Status Ascribed Essay Achieved Status
Developing nations also need technical support and practical advice. You can also use the Wanted Poster for any fairy tale villain you are readin. Ascribed Status And Achieved Status Essay Cause And Effect Essay Outline Ppt
How To Contribute Society Spm Essay
There are currently Ascribed Status And Achieved Status Essay 5 treaties which govern how countries operate in outer space. Literature, however, as it draws inspiration from the human body and its biomedical management, produces several emergent yet unexplored models that challenge the dominant image of Canadian citizenry.
Free Sample Comparative Essay Leaving Cert Cultural Context
How Do I A Analysis Essay For English Class The first is a master services agreement MSA , which defines your services and liabilities in general terms; this will be the same for all your clients. Research paper topics master thesis dissertation database research detailed outline. Because he foolishly believed that one can Ascribed Status And Achieved Status Essay be a soldier and exercise his rights as a man at the same time, the military authorities punished him severely. Whilst the nature of each measure with which they assume is his castle, and when you choose to have transfer value to different degrees. Essay about love nature how to structure a comparison poem essay. What type of essay has a thesis, essay about mind mapping documented argument essay topics how to write a historical argumentative essay importance of trees essay words how to start a persuasive essay hook in Essay about hindi season winter behavior modification essay helpme. However, we would not have been to overcome these obstacles unless we both accepted and understood the concept of generational gaps and its effects on ideals. This system allows each person to argue their innocence before a jury. Creation con essays papers, and many of people everyone is a limited liability company. Consider first the problem of how sensory information gets from my physical body into my spirit-mind.
Death of a salesman relationships essay essay Ascribed Status And Achieved Status Essay about the girl who silenced the world for 5 minutes! All are written in the most elegant and simultaneously accessible writing, much of it really funny the one exception to "funny" is the last essay in the book, the moving and poignant "Under Water". These itinerant courts, each presided over by a judge of the provincial division, periodically conduct hearings at remote areas outside the seat of the high court designated by the judge president of the provincial division concerned. | <urn:uuid:4be361bb-2104-4e44-bed8-9343bab4ad08> | CC-MAIN-2022-33 | https://i-solve.info/ascribed-status-and-achieved-status-essay | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.925443 | 506 | 2.1875 | 2 |
This website is one expression of Earthseed, one which strives to realize the vision of Earthseed as a religion, a religion which inspires people to shape God in the direction of a more just, verdant, and peaceful world.
Others have been drawn to Butler’s writings for different reasons. And many of them are working to shape Change in different ways. We honor them all.
We are Earthseed, but neither this website, nor the those who have gathered around it, are the exclusive representatives of Earthseed. The following excerpts from the Book of the Living describe what Earthseed is:
We are Earthseed
The life that perceives itself
We are Earthseed. We are flesh—self aware,
questing, problem-solving flesh. We are that
aspect of Earthlife best able to shape God
Earthseed is all that spreads
Earthlife to new earths.
These verses describe an inclusive vision of Earthseed. According to verse 20, all humans are Earthseed, because we have the ability to perceive Change. According to verse 22, we all have the potential to be Earthseed, when we Shape God knowingly, i.e., with wisdom and forethought (verse 43), generosity and compassion (verse 53), for the benefit of the world. According to verse 10, none of us are Earthseed yet, because we have yet to spread Earthlife to new earths — but we can all work toward that Destiny.
This website is just one expression of this vision. We are Earthseed, but we are not the only Earthseed. | <urn:uuid:f53133fc-bb4a-4612-ba90-6edc4ca635f2> | CC-MAIN-2022-33 | https://godischange.org/disclaimer/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.947813 | 342 | 1.640625 | 2 |
Get It Filled 2
75.79% players like this free online game according to 40 votes.
Recommended Screen Dimension:
Mobile Phone, Tablet / Pad, Desktop
How To play Get It Filled 2:
Slide to play
Get It Filled 2 is the second game of the puzzle game series Get It Filled. Slide the square to draw a line to fill the blank area, more levels and challenges are waiting for you, just start the game and have fun! You can call your friends to see who can pass more levels, enjoy the Get It Filled 2!
TopMathGames.Com offers free online games for kids, boys and girls. You can play all these games on mobile, tablet and PC without installation. We have math games, logic games, cool puzzle games, educational games, brain training games and more! To play a game, simply use your finger to control if you are playing on your mobile phone or tablet, or use your keyboard and mouse if you're playing on your desktop. You can play a game directly in a browser by visiting TopMathGames.Com. All games on the site are developed or sponsored by TopMathGames.Com so we can make sure that all games are friendly to kids. We add brand new games daily so you will never get bored at here. Enjoy!
- Level Games
- Kids Games | <urn:uuid:7d771008-dd76-4f44-85c6-b09d6b427620> | CC-MAIN-2022-33 | https://www.topmathgames.com/Get-It-Filled-2 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.920776 | 321 | 1.601563 | 2 |
Slime molds are the red-headed stepchildren of the garden world. Not a plant, not an animal, recent research has created more questions than answers about this garden visitor.
This species will appear in your garden. It won't hurt your crops, in fact, it makes nutrients more readily available. This is one of those topics that just caught my attention and I decided to share what I found. Enjoy!
Slime molds often appear after it rains. They can be yellow, red, orange, blue, gray, black, clear, beige, or even hot pink. They can be flat, lumpy, or a fat, rounded glob. Some slime molds look like thousands of tiny balls, while others look like thready networks. One group is called dog vomit slime mold! Slime molds usually grow on rotting wood and mulch, but they can also occur on tree and shrub leaves, berries, succulents, and other plants. The presence of slime mold does not hurt living plant tissue, since it doesn’t usually last for very long. At one stage, they look like somebody spilled something foamy on the ground (the infamous dog vomit slime mold). Slightly disturbing, these shiny, lumpy spills move on their own volition, yet they have no brains. At another stage, tiny, individual critters look more like flowering moss, with a small sphere waving around at the end of a stalk. Slime molds (myxomycetes) are affectionately referred to as "myxos" by scientists and other fans.
Slime mold taxonomy
Slime molds are members of the Protista kingdom. Believed to be over a billion years old, slime molds are considered to be life’s first attempt at joining individual cells into complex organisms. There are actually two types of slime mold: acellular and cellular. Acellular slime molds have many nuclei (the part of a cell that holds DNA), but only one cell wall, during the plasmodium stage. There are 1,000 known species of acellular slime molds. There are only 70 species of cellular slime molds, which are made up of individual cells.
Slime mold lifecycle
All slime molds start out as spores, but the way they get there is amazing. Cellular slime molds, as individual cells, emit a chemical that calls other cells to huddle up into a slug-like structure that eventually becomes a stalk, rather than a blob. These mindless stalks are able to spew ammonia to keep competitors away, as they generate spores. Spores are then released from these parenting bodies, usually into the wind or on a water spray (like fungi). The spores then germinate (like seeds) and then join with other germinated spores to form zygotes (like mammals). These single-celled zygotes feed on decaying wood, fungi, bacteria, and plant material, growing into a mass called a plasmodium. These plasmodium can reach several feet in diameter, with no neurons and no central nervous system, but a surprising ability to solve problems. [The largest recorded slime mold was nearly 60 square feet in size!]
Crazy experiments with slime molds
We humans think that we’re pretty smart. We attribute some level of intelligence to our pets and other favored species. As life forms become more foreign, we are less likely to consider intellect or self-awareness, but this might have to change, in light of recent experiments:
Slime molds will not hurt your garden, unless they are very thick and very persistent. In fact, they help break down dead complex structures into nutrients that your plants can use. Usually, they are only visible for a short time. If you absolutely cannot stand the sight of slime molds, you can use a powerful spray of water to break them up (and spread spores in all directions), dig them up with a pitchfork or shovel and add them to the compost pile, or apply fixed copper to the area. Keep in mind that slime molds will reappear in areas with plenty of shade, moisture, and organic material, no matter how many times you try to get rid of it.
You can grow a surprising amount of food in your own yard. Ask me how!
To help The Daily Garden grow, you may see affiliate ads sprouting up in various places. These are not weeds. Pluck one of these offers and, at no extra cost to you, I get a small commission. As an Amazon Associate I earn from these qualifying purchases. You can also get my book, Stop Wasting Your Yard! | <urn:uuid:4a458ae3-1973-45cd-a02d-bbb0042a64e1> | CC-MAIN-2022-33 | https://www.thedailygarden.us/garden-word-of-the-day/slime-molds | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.952095 | 980 | 3.09375 | 3 |
Australian prisoners are far more likely to smoke than the general population and find it difficult to quit in prison, according to a report released today by the Australian Institute of Health and Welfare (AIHW).
The report, Smoking and quitting smoking among prisoners 2012, shows that 84% of prison entrants were current smokers in 2012-5 times the rate of the general population.
'The decline in smoking rates among the general population seen in the last 20 years has not been mirrored among prisoner populations,' said AIHW spokesperson Tim Beard.
'Among prisoners we also see a concentration of characteristics that are more common among people who are likely to smoke. For example, over a quarter identify as Indigenous Australians. They also tend to come from areas of low socio economic status; have relatively high unemployment rates; and report relatively low levels of education compared to the general population.'
The report shows that 5% of prison dischargees (that is, prisoners who were preparing to be discharged within the four week period following the data collection) who were non-smokers on entry to prison started smoking while in prison.
A further 42% of prison dischargees who were current smokers reported smoking more when leaving prison than when they entered.
Mr Beard said 46% of prison entrants who were current smokers said they would like to quit.
'But it's plainly not easy, with just 1 in 12 prison dischargees being successful in quitting smoking, while a further 27% tried to quit but were unsuccessful.'
When asked what assistance, if any, prisoners would like to help them quit, 35% said none, 30% said nicotine replacement therapy and 21% said programs to help quit smoking.
All jurisdictions in Australia have at least some restrictions on smoking in prisons, and in July 2013 a complete ban on smoking for prisoners, staff and visitors was introduced into prisons in the Northern Territory.
'Smoking among prisoners is associated with other risky behaviours,' Mr Beard said.
'For instance, 75% of prisoners who smoked had used illicit drugs in the 12 months before they entered prison, compared with only 29% for prisoners who had never smoked.
'And 51% of ex-smokers and 48% of current smokers were at risk of alcohol-related harm before entering prison, compared with 27% for those who had never smoked.'
The AIHW is a major national agency set up by the Australian Government to provide reliable, regular and relevant information and statistics on Australia's health and welfare.
We'd love to know any feedback that you have about the AIHW website, its contents or reports.
The browser you are using to browse this website is outdated and some features may not display properly or be accessible to you. Please use a more recent browser for the best user experience. | <urn:uuid:02a41bf6-74b8-4be5-93bb-7290c62b8765> | CC-MAIN-2022-33 | https://pp.aihw.gov.au/news-media/media-releases/2013/october/84-of-prison-entrants-smoke-quitting-in-prison-i | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.973276 | 596 | 2.203125 | 2 |
This is a mini-universe of web-based and print resources to support your academic work on the intersection of gender and culture, so that you don't need to rely on your first Google result or search in every database.
If you don't find what you're looking for or have any questions, contact your librarian!
We hear it every day: Women are more professionally and financially successful than they've ever been, but society hasn't entirely made peace with that. A new study underscores that point, indicating that women bringing home more money than their male partners are still expected to fulfill traditional roles in relationships.
One curious thing about popular culture is that men's magazines and women's magazines often follow the same general formula. Men's magazines are mostly based around heavily eroticized images of women. And women's magazines are also based around heavily eroticized images of women | <urn:uuid:8f0a07e1-6a68-4ca7-bd04-6844bc1c4055> | CC-MAIN-2022-33 | https://mcphs.libguides.com/gender_and_culture | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571502.25/warc/CC-MAIN-20220811194507-20220811224507-00065.warc.gz | en | 0.977331 | 176 | 1.796875 | 2 |
U.N. report: "China now appears to be the largest e-waste dumping site in the world"
Products originally produced in China are now finding their way back as electronic junk
The small town of Guiyu as been a major hub for the disposal of e-waste
"When recycling is done in primitive ways ... it is hugely devastating for the local environment"
Did you ever wonder what happens to your old laptop or cellphone when you throw it away?
Chances are some of your old electronic junk will end up in China.
According to a recent United Nations report, “China now appears to be the largest e-waste dumping site in the world.”
E-waste, or electronic waste, consists of everything from scrapped TVs, refrigerators and air conditioners to that old desktop computer that may be collecting dust in your closet.
Many of these gadgets were initially manufactured in China. Through a strange twist of global economics, much of this electronic junk returns to China to die.
“According to United Nations data, about 70% of electronic waste globally generated ended up in China,” said Ma Tianjie, a spokesman for the Beijing office of Greenpeace.
“Much of [the e-waste] comes through illegal channels because under United Nations conventions, there is a specific ban on electronic waste being transferred from developed countries like the United States to countries like China and Vietnam.”
For the past decade, the southeastern town of Guiyu, nestled in China’s main manufacturing zone, has been a major hub for the disposal of e-waste. Hundreds of thousands of people here have become experts at dismantling the world’s electronic junk.
On seemingly every street, laborers sit on the pavement outside workshops ripping out the guts of household appliances with hammers and drills. The roads in Guiyu are lined with bundles of plastic, wires, cables and other garbage. Different components are separated based on their value and potential for re-sale. On one street sits a pile of green and gold circuit boards. On another, the metal cases of desktop computers.
At times, it looks like workers are reaping some giant plastic harvest, especially when women stand on roadsides raking ankle-deep “fields” of plastic chips.
In one workshop, men sliced open sacks of these plastic chips, which they then poured into large vats of fluid. They then used shovels and their bare hands to stir this synthetic stew.
“We sell this plastic to Foxconn,” one of the workers said, referring to a Taiwanese company that manufactures products for many global electronics companies, including Apple, Dell and Hewlett-Packard.
Dirty, dangerous work
This may be one of the world’s largest informal recycling operations for electronic waste. In one family-run garage, workers seemed to specialize in sorting plastic from old televisions and cars into different baskets. “If this plastic cup has a hole in it, you throw it away,” said a man who ran the operation, pointing to a pink plastic mug. “We take it and re-sell it.”
But recycling in Guiyu is dirty, dangerous work. “When recycling is done properly, it’s a good thing for the environment,” said Ma, the Greenpeace spokesman in Beijing.
“But when recycling is done in primitive ways like we have seen in China with the electronic waste, it is hugely devastating for the local environment.”
According to the April 2013 U.N. report “E-Waste in China,” Guiyu suffered an “environmental calamity” as a result of the wide-scale e-waste disposal industry in the area.
Much of the toxic pollution comes from burning circuit boards, plastic and copper wires, or washing them with hydrochloric acid to recover valuable metals like copper and steel. In doing so, workshops contaminate workers and the environment with toxic heavy metals like lead, beryllium and cadmium, while also releasing hydrocarbon ashes into the air, water and soil, the report said.
For first-time visitors to Guiyu, the air leaves a burning sensation in the eyes and nostrils.
Studies by the Shantou University Medical College revealed that many children tested in Guiyu had higher than average levels of lead in their blood, which can stunt the development of the brain and central nervous system.
Piles of technological scrap had been dumped in a muddy field just outside of town. There, water buffalo grazed and soaked themselves in ponds surrounded by piles of electronic components with labels like Hewlett-Packard, IBM, Epson and Dell.
The enormous animals casually stomped through mounds of sheet glass, which clearly had been removed from video monitors.
Flat screen displays often use mercury, a highly toxic metal.
“Releases of mercury can occur during the dismantling of equipment such as flat screen displays,” wrote Greenpeace, in a report titled “Toxic Tech.” “Incineration or landfilling can also result in releases of mercury to the environment…that can bioaccumulate and biomagnify to high levels in food chains, particularly in fish.”
Most of the workers in Guiyu involved in the e-waste business are migrants from destitute regions of China and poorly educated. Many of them downplayed the potential damage the industry could cause to their health.
They asked only to use their family names, to protect their identity.
“Of course it isn’t healthy,” said Lu, a woman who was rapidly sorting plastic shards from devices like computer keyboards, remote controls and even computer mice. She and her colleagues burned plastic using lighters and blow-torches to identify different kinds of material.
“But there are families that have lived here for generations … and there is little impact on their health,” she said.
Several migrants said that while the work is tough, it allows them more freedom than working on factory lines where young children are not permitted to enter the premises and working hours are stringent.
Used to be worse
Despite the environmental degradation and toxic fumes permeating the air, many in Guiyu said that conditions have improved dramatically over the years.
“I remember in 2007, when I first came here, there was a flood of trash,” said Wong, a 20-year-old man who ferried bundles of electronic waste around on a motorcycle with a trailer attached to it.
“Before people were washing metals, burning things and it severely damaged people’s lungs,” Wong added. “But now, compared to before, the [authorities] have cracked down pretty hard.”
But residents who did not work in the e-waste business offered a very different take on the pollution in Guiyu.
A group of farmers who had migrated from neighboring Guangxi province to cultivate rice in Guiyu told CNN they did not dare drink the local well water.
They claimed if they tried to wash clothes and linens with the water, it turned fabrics yellow.
The head of the group, who identified himself as Zhou, had another shocking admission.
“It may not sound nice, but we don’t dare eat the rice that we farm because it’s planted here with all the pollution,” Zhou said, pointing at water-logged rice paddy next to him.
Asked who did eat the harvested rice, Zhou answered: “How should I know? A lot of it is sold off … they don’t dare label the rice from here as ‘grown in Guiyu.’ They’ll write that its rice from some other place.”
Not that surprising considering that the latest food scandal to hit the country earlier this month is cadmium-laced rice. Officials in Guangzhou city, roughly 400 kilometers away from Guiyu, found high rates of cadmium in rice and rice products. According to the city’s Food and Drug Administration samples pulled from a local restaurant, food seller and two university canteens showed high levels of cadmium in rice and rice noodles. Officials did not specify how the contaminated rice entered the city’s food supply.
CNN made several attempts to contact the Guiyu town government. Government officials refused to comment on the electronic waste issue and hung up the phone.
However, it did appear that government efforts to restrict imports of foreign waste are reducing the flow of e-trash here.
“Why are they stopping the garbage from reaching us?” asked one man who ran a plastic sorting workshop. “Of course it’s hurting our business,” he added.
Domestic e-waste grows
The Chinese government had some success regulating e-waste disposal with a “Home Appliance Old for New Rebate Program,” which was tested from 2009 to 2011.
With the help of generous government subsidies, the program collected tens of millions of obsolete home appliances, according to the U.N.
Even if Chinese authorities succeed in limiting smuggled supplies of foreign garbage, the U.N. warns that the country is rapidly generating its own supply of e-waste.
“Domestic generation of e-waste has risen rapidly as a result of technological and economic development,” the U.N. reported. It cited statistics showing an exponential surge in sales of TV’s, refrigerators, washing machines, air conditioners and computers in China over a 16-year period.
To avoid a vicious cycle of pollution, resulting from both the manufacture and disposal of appliances, Greenpeace has lobbied for manufacturers to use fewer toxic chemicals in their products.
The organization also has a message for consumers who seem to swap their phones, tablets and other computer devices with increasing frequency.
“Think about where your mobile phone or where your gadgets go,” said Ma, the Greenpeace activist.
“When you think about changing [your phone], or buying a new product, always think about the footprint that you put on this planet.”
Connie Young contributed to this story | <urn:uuid:54fed092-8676-4a5f-ba14-ae671b758a53> | CC-MAIN-2022-33 | https://www.cnn.com/2013/05/30/world/asia/china-electronic-waste-e-waste/index.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.95436 | 2,140 | 2.546875 | 3 |
Concerts of excerpts can often make for grim evenings lacking in depth, but the energy and enthusiasm with which the Birmingham Philharmonic performed on Sunday meant this simply wasn’t possible.
Presenting a programme inspired by myth and magic, any sceptical notion of the orchestra shielding itself by careful selection was dispelled by certain inclusions.
The Sorcerer’s Apprentice was one. None of the nuances in this rich score were overlooked. The tune was characterfully delivered by the bassoons and trumpets, and the contrabassoon’s moment of glory was joyous. In a concert showcasing magic, any other orchestra lacking the confidence or the quality would have conveniently forgotten Dukas’s mini-masterpiece.
Concluding with John Williams’s music for Star Wars also demonstrated the confidence with which the orchestra was performing, and it certainly was not foolhardy. The way the BPO responded to the unquestionably demanding score, especially in the effective percussion and gutsy brass, was truly astounding.
Tellingly, it was in the programme’s 19th-century elements where the few problems manifested themselves. Despite their numbers, the strings struggled to compete in tone and volume with the superb winds. Whilst not disrupting the concert’s more contemporary items, this became problematic when faced with the broad, expansive phrases of Smetana’s Ma Vlast and Weber’s Oberon Overture.
Overall, though, the standard achieved was astonishing, and Richard Laing, who conducted with a consistent vigour and enthusiasm, deserves particular praise.
Rating * * * * | <urn:uuid:00838251-4f2d-4c47-b0bd-dee4bc5b75a7> | CC-MAIN-2022-33 | https://www.business-live.co.uk/retail-consumer/review-birmingham-philharmonic-orchestra-adrian-3925441 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.9666 | 332 | 1.5 | 2 |
Protocols and test procedures are specified for the measurement of the peak spatial-average SAR induced inside a simplified model of the head of users of certain handheld radio transceivers. These transceivers are intended to be used for personal wireless communications services, operate in the 300 MHz to 6 GHz frequency range, and are intended to be operated while held against the ear. The results obtained by following the protocols specified in this recommended practice represent a conservative estimate of the peak spatial-average SAR induced in the head of a significant majority of persons, subject to measurement and other uncertainties that are defined in this recommended practice. The results are representative of those expected during conditions of intended use of a handheld wireless device. It is not the intent of this recommended practice to provide a result representative of the absolute maximum SAR value possible under every conceivable combination of head size, head shape, handset orientation, and spacing relative to the head. The measurement of SAR induced in the external tissues of the head, e.g., the external ear (pinna), is not addressed in this document. This recommended practice also does not address the body SAR measurements typically required for wireless handsets. The following items are described in detail: measurement concepts, measurement techniques, instruments, calibration techniques, simulated-tissue (phantom) models, including homogeneous anatomically equivalent models of the human head and simple phantoms for validation of the SAR measurement system, and the limitations of these systems when used for measuring the spatial-peak mass-averaged SAR. Procedures for calibrating electric field (E-field) probes used for SAR measurements and assessing the SAR measurement and system uncertainties are provided in the annexes. This recommended practice is intended primarily for use by engineers and other specialists who are familiar with electromagnetic (EM) theory and SAR measurement techniques; it does not recommend specific SAR limit values since these are found in other documents. The benefits to the users include standardized and accepted protocols, validation techniques, and means for estimating the overall measurement uncertainty in order to produce valid and repeatable data.
Working Group Details
- IEEE-SASB Coordinating Committees
- Sponsor Committee
- SASB/SCC39 - SCC39 - International Committee on Electromagnetic Safety
- Working Group
P62209-3 - Measurement procedure for the assessment of specific absorption rate of human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices - Part 3: Vector measurement-based systems (Frequency range of 600 MHz to 6 GHz)
- IEEE Program Manager
- Patricia Roder
- Working Group Chair
- Teruo Onishi
IEEE Guide for EMF Exposure Assessment of Internet of Things (IoT) Technologies and Devices
In the wireless communication field, 5G and Internet of Things (IoT) solutions are the main emerging technologies and future wireless communication will rely on them. A methodology for classifying IoT devices based on radio frequency (RF) exposure characteristics is provided. Classification is based on frequency, bandwidth, radiated power, and typical installation configuration. Links between device class and available measurement/computational standards are provided. A framework criterion for exclusion classes for exposure assessment and criteria for addressing situations where exposure assessment is unavailable are included.
IEC/IEEE International Standard - Measurement procedure for the assessment of specific absorption rate of human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices u2013 Part 1528: Human models, instrumentation, and procedures (Frequency range of 4 MHz to 10 GHz)
Replaces IEC 62209-1:2016, IEC 62209-2:2010, and IEEE Std 61528:2013 and supersedes IEEE Std 1528-2013
IEEE Recommended Practice for Determining the Peak Spatial-Average Specific Absorption Rate (SAR) in the Human Head from Wireless Communications Devices: Measurement Techniques - Amendment 1: CAD File for Human Head Model (SAM Phantom)
Amendment to IEEE Std 1528-2003. This amendment to IEEE Std 1528 addresses certain text ambiguities in IEEE Std 1528-2003 and provides a CAD data file for the human head model from the original project but which was not included with the original standard. | <urn:uuid:40770f80-8c45-400c-9c4a-03c0a5f2f4ec> | CC-MAIN-2022-33 | https://standards.ieee.org/ieee/1528/4418/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.887003 | 902 | 2.109375 | 2 |
MAM to give Rs. 100,000 to Families of People Who Perished in Idukki Landslide
The Mata Amritanandamayi Math (MAM) will be providing Rs. one lakh to families in Kerala’s Idukki District who lost family members in landslides that struck the region in early August.
The fatal landslides in the region were triggered by one of the heaviest monsoon seasons in Kerala in 20 years. At one point, the district experienced 17 landslides within 24 hours.
“Amma was deeply saddened when she learned of the tragedy,” says Swami Jnanamritananda Puri, MAM’s sannyasi in charge of Idukki District. “She wanted us to reach out to them to show them that we are with them during this difficult time.”
The families will receive the money on the 27th of September during Amritavarsham60.
On the same day, MAM will be officially launching its 50-crore relief-and-rehabilitation programme for Uttarakhand, through which it will rebuild 500 homes destroyed in 42 villages in the region’s June 2013 flash-flooding. It will also be adopting 101 villages throughout India in order to make them self-reliant.
“Whenever the people of India need her, Amma is always there,” says Jnanamritananda. “It doesn’t matter which corner of the country. Amma has responded to disasters in Kerala, Gujarat, Bihar, West Bengal, Tamil Nadu, Maharasthra. She feels the people’s pain as her own and reacts accordingly.” | <urn:uuid:2184a54a-ea6a-412c-98fb-fa39d39d298a> | CC-MAIN-2022-33 | https://www.amritapuri.org/46553/13-idukki.aum | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.965564 | 359 | 1.640625 | 2 |
(2014, 11′, 16mm, sound and compositions: Clay Gold)
A performance in which the artist searches for traces of the river Thames’ ancient past by processing 16mm film on the foreshore using water collected at low tide.
Speculating on memories and traces held within the water, images of water patterns and foreshore detritus are combined with close-up textures of pre-historic objects such as skulls and flint axe-heads discovered in the area, filmed at the Museum of London. Watermarks and particles of ancient river silt cling to the resultant film’s surface, their abstract formations a portal to the unseen forces at work in the river.
Filmed by Rosalind Fowler and Karel Doing, with hand-processing support by James Holcombe.
Supported by NOW gallery
ICA, London Short Film Festival - nominated for Best Experimental Film Award at LSFF 2015, and selected in 2020 as part of a retrospective of artist work through the history of the festival.
Flatpack film festival
Milton Keynes gallery | <urn:uuid:acac71b3-caba-41cd-aba2-d78e0222ec9d> | CC-MAIN-2022-33 | https://www.rosalindfowler.co.uk/home/tamesa/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571869.23/warc/CC-MAIN-20220813021048-20220813051048-00065.warc.gz | en | 0.913441 | 238 | 1.664063 | 2 |
Pedestrians in Leicester will soon be tracked through the Wi-Fi connection on their phones in a bid to ‘better understand shopper behaviour’.
Leicester’s Business Improvement District (BID), a body which works to boost the city centre, is to start using Wi-Fi tracking to identify footfall and shopper behaviour in the city.
The organisation will then inform and support BID levy paying businesses to help improve their performance.
BID Leicester has appointed retail intelligence company Springboard to provide ‘performance footfall, Wi-Fi monitoring and visitor intelligence services’ across the city centre.
This includes the volume of visitors to the BID area, the places they arrive, the time they spend and journey routes.
Data collected will also influence BID Leicester’s planning, delivery and marketing activity.
The BID area covers most of Leicester city centre including the Old Town, Highcross, Cultural Quarter and New Walk.
Businesses within the area currently pay an extra levy on their rates to fund a £4.2 million pot to improve the city centre.
How do you feel about Wi-Fi being used to monitor footfall in the city?
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Simon Jenner, BID Leicester director, said: “Understanding footfall trends in the city is crucial for businesses and I’m pleased to be working with Springboard to bring this technology to Leicester for the first time.
"The service will benefit BID Leicester levy payers, allowing them to access data on footfall trends so that they can better understand shopper behaviour.
"This information will help them to make more informed business decisions, and ultimately drive the growth of local businesses.”
Jonathan Burnett, Springboard High Street Account Manager, added: “We are delighted to be BID Leicester’s chosen supplier of footfall and performance insights following a competitive tender process.
"We look forward to working with the BID team and board to deliver footfall data that can be benchmarked against 200+ other UK High Street locations and understand the pedestrian journeys taken around the city.”
Leicestershire Live contacted BID Leicester to find out more about how the Wi-Fi tracking will work, and when it will be activated. | <urn:uuid:80c7b2cc-d55c-4d58-8a5b-f247b0f99944> | CC-MAIN-2022-33 | https://www.leicestermercury.co.uk/news/leicester-news/shoppers-leicester-city-centre-soon-2482384 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572192.79/warc/CC-MAIN-20220815145459-20220815175459-00065.warc.gz | en | 0.910851 | 473 | 1.507813 | 2 |
The Australian Renewable Energy Agency (ARENA) will provide $981,000 in funding to the University of New South Wales (UNSW) for the development of tools to understand how rooftop solar and distributed energy resources (DER) respond to contingency events across the National Electricity Market (NEM).
The $2.1 million project will look to identify how these assets respond to contingency events such as the sudden loss of a large generator or transmission line, while also assessing opportunities for DER and rooftop solar PV to further protect the NEM from such events in the future.
The study will improve data capture, assess inverter behaviour, inform the development of new standards, and set up tools and frameworks for long-term monitoring of solar and DER asset behaviour.
The Australian Energy Market Operator (AEMO) and solar monitoring company Solar Analytics are also partnering on the UNSW project.
As part of the study, UNSW will assess inverter compliance rates, identify possible improvements to existing inverter standards, and provide AEMO with new tools to more effectively operate a safe, secure and reliable power system with high levels of rooftop solar in the grid.
To maintain power system security in the NEM, AEMO must consider a range of contingency events. The system needs to withstand these contingency events and quickly return to its regular secure operating conditions.
AEMO’s Renewable Integration Study has identified that high penetration of rooftop solar presents challenges to power system security and that the impacts of it are already occurring, and are expected to increase over the next five years.
Once developed, UNSW’s tools have the potential to help address many of the recommendations made in the Renewable Integration Study, such as informing the refinement of technical performance standards, and establishing real-time visibility of rooftop solar and DER assets.
ARENA CEO, Darren Miller, said UNSW’s project was a great opportunity to understand how rooftop solar reacts in contingency events and how it can be improved upon.
“UNSW’s project is an exciting step in developing the vital components for rooftop solar and DER and the benefits they bring to supporting the electricity grid,” Mr Miller said.
“Integrating renewables into the electricity system is a key priority for ARENA, so the tools being developed throughout the project will help to ensure that Australia’s record-breaking solar installations continue to be of benefit to the grid and in helping with system security.” | <urn:uuid:42cd6532-5da4-4aa1-87e6-bdd08221a7a0> | CC-MAIN-2022-33 | https://utilitymagazine.com.au/arena-funds-solar-and-der-contingency-response-study/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.929047 | 508 | 1.796875 | 2 |
India's largest university will ink a pact with telecom major Ericsson on Thursday to provide facilities supported by 3G Mobile services in Open and Distance education.
"IGNOU university is open to latest technologies that can be used to reach maximum students. We specifically target rural students who cannot always have a one to one meeting with teachers to clear their doubts among other things," IGNOU Vice Chancellor V N Rajasekharan Pillai said.
"A certificate course in IT, covering 5,000 students, will be held as the pilot project in which the 3G service will be utilised. Based on its success we will then chart out courses and contents," IGNOU VC K R Srivasthan, who conceived the idea, said.
Under the programme, mobile service provider Ericsson, which has a network practically covering the entire north-east, will help in students access parts of the course web pages, download files like assignments and video clips.
"The service will be available in any mobile handsets having a 3G service," Goton Achaibar, President and Country head of Ericsson India said in reply to a query.
The 3G technology helps a learner stream through video, audio and selective Internet browsing. New notebooks with built-in 3G chip sets advanced e-learning services, which will allow consulting with academic counsellors, course co-ordinators, peer-to peer discussions etc., Srivasthan said.
The total investment in rolling out the project will be worked out on the basis of the pilot project.
"Each student may have to shell out an additional around Rs 25 to the service charges they are paying now. Also the government should give concession to those who cannot afford it. More students using the facility means less cost per head," Pillai said.
When asked whether students especially in rural areas can afford handsets with 3G service, Srivasthan said, "Our aim is to create a 3G technology platform. So the student can go to the nearest Internet or link and make use of the facility."
"Techniques like web-mentoring and web-procuring will help students to have not only a two-way audio and video interactives, but also access a delivery of classroom discussion or a seminar.
Ericsson India Chief, Achaibar, said the roll out process (after the pilot project) is relatively easy in India as it has established network providers (BSNL, MTNL), a large per cent of mobile users besides technology.
"700 million people in India are outside metro areas.But we are encouraged with the success of 2G which has 400 million customers. Also two-third of its population are mobile users," he said.
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- Electronic, Car Cos Hit Top Gear to Step Up Festive Output
Companies manufacturing cars, smartphones, televisions, refrigerators and washing machines are ramping up festive season production by up to 50% compared with the corresponding period a year ago, anticipating robust sales and buoyed consumer sentiment in the next three-four months.Amid Curbs, India-Russia Trade Via INSTC Booms
The International North-South Transport Corridor (INSTC) has been facilitating a higher volume of trade between India and Russia via Iran over the last three months amid the West’s sanctions on Moscow following the Ukraine war.Market Share of Private Fuel Retailers Falls 50-80% in a Year
The combined share of private players—Reliance-BP, Shell and Rosneft-backed Nayara Energy—has shrunk by 50-80% in the fuel retail market year-on-year and even the taxes imposed in July on exports or the official mandate to sell more in the domestic market hasn’t helped.
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3 mins read | <urn:uuid:5ed2a0fd-7e2d-4f9e-8ea6-4eb189e2cdb5> | CC-MAIN-2022-33 | https://economictimes.indiatimes.com/news/news-by-industry/services/education/IGNOU-ties-up-with-Ericsson-for-3G-Mobile-education-services/articleshow/5163454.cms | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.93551 | 820 | 1.835938 | 2 |
People who took part in the protests against the G8 summit in Scotland were flung abruptly from another high point of the anti-capitalist movement back into the global state of emergency proclaimed by George Bush after 9/11.
This was symbolised by the experience of those of us who returned from Edinburgh on Thursday last week, the day of the London bombings, on the Globalise Resistance train.
When we arrived at Euston that evening, we were greeted by perhaps 100 police officers, who filmed us as we got off. No wonder Al Qaida is running rings round the British state with such absurd priorities reigning in Scotland Yard.
But the bombings shouldn’t be allowed to obscure the significance of the protests in Scotland. In the first place, Tony Blair’s and Gordon Brown’s attempt to co-opt the global justice movement failed.
Upwards of 300,000, the demonstration in Edinburgh on Saturday 1 July was the biggest yet seen at a G8 summit — bigger even than the historic march in Genoa on 21 July 2001.
The organisers of Make Poverty History had tried to suppress any reference to the war in Iraq. Yet the march was covered in anti-war placards and slogans and the Stop the War Coalition mounted a highly successful rally at the end.
In many ways the London bombings have been very convenient for Blair. They helped to obscure the fact that the summit completely failed to live up to his and Brown’s promises.
This is reflected in the row between Bob Geldof and even the most mainstream non-governmental organisations involved in Make Poverty History such as Oxfam and Christian Aid. They have denounced the paltry measures against global poverty that were agreed at the summit.
Secondly, the G8 Alternatives march on Wednesday of last week asserted the right to protest at the very gates of Gleneagles. The huge police operation failed to prevent the demonstration and couldn’t even stop protesters breaking through part of the security fence.
Thirdly, G8 Alternatives also mounted a highly successful counter-summit in Edinburgh on Sunday 2 July. Some 5,000 people attended the counter-summit. The participants were overwhelmingly from Scotland itself.
They packed into plenaries and workshops to follow and take part in an immense variety of different debates. I spoke alongside George Monbiot at a huge workshop organised by Globalise Resistance on alternatives to neo-liberalism.
The workshop involved a stimulating discussion about how to ensure that the planet has a future.One thing that struck me was the youth of many of those taking part.
The Stop the War Coalition mounted a very moving Naming of the Dead rally on Calton Hill in Edinburgh on the Sunday evening.
Many of those there could only have been 11 or 12 at the time of the Seattle protests. They were becoming part of a movement whose origins they were too young to remember properly.
Like the European Social Forum in London last October and the victory of the left no campaign in the French referendum on the European constitution, the Scottish protests offered a spectacular confirmation of the enduring strength and the wide diffusion of anti-capitalist consciousness.
We have also been given a very strong reminder that the anti-capitalist movement can only remain effective if it challenges not simply corporate globalisation but also imperialism and war.
A heavy responsibility falls on the shoulders of those in the movement to find ways to continue to give expression to opposition to capitalism and war and to help it grow. It is here that, amid the horror that increasingly grips the world, the real hope for a better future is to be found. | <urn:uuid:aeeb1d4a-3aa4-4d34-8cee-579ba3925edb> | CC-MAIN-2022-33 | https://www.indymedia.org.uk/en/regions/london/2005/07/318078.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.96493 | 758 | 1.765625 | 2 |
Pallets play an important role in the storage and transportation of merchandise. The pallets took less effort to maneuver heavy stacks. Warehouse space can be managed well by using pallets for storage. This consequently lowers the costs associated with handling and storage solutions.
Pallets for transport can be produced from other materials such as wood, metal and plastic. What's more, they may also be utilized as standardized measurement components as their dimensions may be customized. Also, you can easily;y get them by contacting a pallet supplying firm online.
You can click over here- https://www.affordablepallets.com.au/pallets/custom-pallets/ to get pallets for your industrial needs. Among the benefits of pallet shipping is the fact that pallet shipping ensures efficacy. This is due to the fact that nearly all of them are light in weight and also desire a little room for storage.
Image Source – Google
Pallets don't occupy a great deal of room yet they take a lot of products in them. Additionally, pallets used for transport are powerful. Their strength also makes it feasible to stack a range of things together without breaking up one.
The best benefit of expedited transport is portability. Most pallets are made to be easily transported around by one person. They are available in various sizes, which range from little to large pallets.
As the majority of the pallets are made from metal and plastic, they can readily be melted and recast into many different shapes to generate new ones. | <urn:uuid:49f0a37c-771d-477c-91ff-c9a46bc2ba4f> | CC-MAIN-2022-33 | https://www.esgobaethbangordiocese.org/tag/pallets-supplier/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571869.23/warc/CC-MAIN-20220813021048-20220813051048-00065.warc.gz | en | 0.967431 | 313 | 2.21875 | 2 |
Rosetta Rendezvous Mission with Comet 67P/Churyumov-GerasimenkoSpacecraft Launch Sensor Complement Philae Mission Status References
Rosetta is a deep space mission of ESA , it is the first mission designed to both orbit and land on a comet. ESA selected the mission in Nov. 1993 as the third cornerstone mission in its long-term science program, called 'Horizon 2000'. The goal of the Probe is to rendezvous with the Comet 67P/Churyumov-Gerasimenko and map its surface in fine detail. It will also land a package of instruments (the Philae Lander) to study some of the most primitive, unprocessed material in the solar system. 1)
Comets are among the most beautiful and least understood nomads of the night sky. To date, half a dozen of these most heavenly of heavenly bodies have been visited by spacecraft in an attempt to unlock their secrets. All these missions have had one thing in common: the high-speed flyby. Like two ships passing in the night (or one ship and one icy dirtball), they screamed past each other at hyper velocity — providing valuable insight, but fleeting glimpses, into the life of a comet. That is, until Rosetta.
Launched in March 2004 and expected to reach the comet by 2014, Rosetta will be the first mission to revolve around the comet's nucleus and deliver a lander to its surface. The spacecraft will be located at a distance of 600 million km or 4AU (astronomical units) from the sun upon the comet.
Table 1: Some background on the Rosetta mission 2)
Figure 1: The Rosetta Stone is displayed at the British Museum in London since 1802 (image credit: British Museum)
Legend to Figure 1: The Rosetta Stone is a granodiorite stele inscribed with a decree issued at Memphis in 196 BC on behalf of King Ptolemy V. The decree is given in three languages: Egyptian hieroglyphs (top), Demotic (middle), and ancient Greek (bottom). Champollion used the Greek to decipher the hieroglyphs (a full decipherment was published in 1824). The Rosetta Stone provided the key to the modern understanding of Egyptian hieroglyphs. The Rosetta Stone has a size of 114.4 cm x 72.3 cm x 27.93 cm. 3)
The measurements goals of the Rosetta mission are: 4)
- a global characterization of the nucleus
- the determination of its dynamic properties
- the surface morphology and composition
- the determination of chemical, mineralogical and isotopic compositions of volatiles and refractories in the cometary nucleus
- the determination of the physical properties and interrelation of volatiles and refractories in the cometary nucleus
- studies of the development of cometary activity and the processes in the surface layer of the nucleus and inner coma, that is dust/gas interaction
- studies of the evolution of the interaction region of the solar wind and the outgassing comet during perihelion approach.
Rosetta is truly an international enterprise, involving more than 50 industrial contractors from 14 European countries and the United States. The prime spacecraft contractor is Airbus Defence and Space (formerly EADS Astrium, GmbH, Friedrichshafen, Germany), responsible for building the spacecraft. Other contributions were provided by Airbus Defence and Space UK (spacecraft platform), and Airbus Defence and Space France (spacecraft avionics) and Alenia Spazio (assembly, integration and verification) are major subcontractors.
Rosetta comprises a large orbiter, which was designed to operate for a decade, and a lander. Each of these components carries a large array of scientific instruments that will perform the most extensive study of a comet to date. The orbiter will revolve around the comet from 1km distance examining the nucleus and environment of the comet.
The Rosetta orbiter is a platform of size 2.8 m x 2.1 m x 2 m (an aluminum box) with a payload support module, which houses the 11 scientific instruments, mounted on the top and a bus support module, housing the subsystems, on the base. Two sets of solar panels with 14 m length having an area of 64m2 extend from the side of the spacecraft and a 2.2 m diameter steerable, high-gain antenna dish sticks out from the front. The lander is attached to the back of the orbiter. The two solar panel wings rotate at ±180° to capture the maximum sunlight. 5) 6)
The spacecraft is built around a vertical thrust tube, whose diameter corresponds to the 1.194 m Ariane-5 interface. This tube contains two large, equally sized propellant tanks (each of 1106 liter), the upper one containing fuel, and the lower one containing the (heavier) oxidizer. The Orbiter also carries 24 thrusters for trajectory and attitude control. Each of these thrusters pushes the spacecraft with a force of 10 Newton, equivalent to that experienced by someone holding a bag of 10 apples. Over half the launch mass of the entire spacecraft, about 1670 kg, is made up of propellant.
Figure 2: Artist's rendition of the deployed Rosetta spacecraft (image credit: ESA)
The spacecraft is three-axis stabilized. Attitude is maintained by four reaction wheels as well as using two star trackers, sun sensors, navigation cameras, and three laser gyro packages. Power is supplied by the solar arrays. The solar cells employed are 200 µm Si solar cells of LLIT (Low Intensity, Low Temperature) type sized 37.75 mm in width and 61.95 mm in length (Figure 3). The cover glass is 100 µm thick ceria doped micro-sheet designated curb mount glass (CMG). The cover-glass covers the solar cell completely. The solar arrays will provide 395 W at 5.25 AU and 850 W at 3.4 AU, when comet operations begin. Power is stored in four 10 Ah NiCd batteries which supply the 28 V bus power.
Figure 3: Close-up of a single solar array cell (image credit: ESA)
The Rosetta deep space mission of ESA represents a rather special case of solar cell technology use. At its destination in 2014, the spacecraft is at a distance of about 675 million km from Earth, corresponding to 4.5 AU, a distance almost as far out as Jupiter , where sunlight levels are only 4% of those on Earth. In LEO (Low Earth Orbit), Rosetta is the most powerful spacecraft that ESA ever built, at 12 kW of installed solar power generation provided by two solar arrays, covered with hundreds of thousands of specially developed non-reflective silicon cells. But at the deep space distance of Comet 67P/Churyumov-Gerasimenko, the total solar power available is only ~400 W. - Rosetta is the first deep space mission ever to rely entirely on solar power generation beyond the main asteroid belt (with sunlight levels of only 3-4% as those in LEO) - without the use of RTG (Radioisotope Thermoelectric Generator) technology (as is being done by all other deep space satellites).
Illumination reduces with distance from the Sun by what is called the inverse square law – if one goes twice as far away only a quarter the solar intensity is available, at three times the distance, only one ninth of the intensity is available. This means that temperatures experienced by the spacecraft also fall with distance, though in principle this is good news for solar cell designers, since cell efficiency increases as the temperature goes down. 7) 8) 9) 10)
In practice however, in low solar intensities with temperatures dropping below –100°C, standard solar arrays show worse-than-expected performance due to unpredictable degradation of individual cells. To overcome this problem, the LLIT (Low Intensity Low Temperature) specific solar cell technology was developed. The resulting single-junction silicon cells are flying on ESA’s Rosetta comet chaser, which is venturing three times further from the Sun than Earth.
Figure 4: Photo of one of Rosetta’s two massive solar wings (each with 5 solar panels), keeping Rosetta powered out in the cold depths of space (image credit: ESA)
Legend to Figure 4: The image was taken in 2002 showing Rosetta being checked in ESA/ESTEC in Noordwijk, The Netherlands. One hinged wing is supported on a rig to allow it to unfurl safely in Earth gravity instead of weightlessness. Each wing is made up of five hinged panels, the steerable pair of wings together stretches 32 m tip-to-tip from the box-shaped spacecraft. 11)
At Rosetta's encounter with the Comet, the spacecraft is experiencing only 11% of Earth-level solar illumination — but still better than the 4% when it was furthest from the Sun. But instead of going nuclear, Rosetta runs solely on LILT (Low-Intensity, Low-Temperature) silicon solar cells, a new European technology devised for this mission, optimized for deep-space conditions. - The same is true of Rosetta’s Philae lander, whose batteries are designed to be recharged by the LILT cells covering its body.
RF communications: Communications is maintained via the high-gain antenna, a fixed 0.8 m medium-gain antenna, and two omnidirectional low gain antennas. Rosetta utilizes an S-band telecommand uplink and S- and X-band telemetry and science-data downlinks, with data transmission rates from 5 to 20 kbit/s. The communication equipment includes a 28 W RF X-band TWTA (Traveling Wave Tube Amplifier) and a dual 5 WRF S/X band transponder. Onboard heaters keep the instrumentation from freezing during the period the spacecraft is far from the sun.
The Rosetta spacecraft had to be designed for a high level of reliability as the main scientific mission is starting more than 10 years after launch, and also for a high level of availability during the early years of the mission cruise, which also contains many key technical and scientifically valuable events including three Earth swingbys, one Mars swingby, two asteroid flybys, several deep space trajectory correction maneuvers, and regularly scheduled onboard system and payload checkouts.
These outstanding efforts will assure that Rosetta will contribute significantly to answer open questions in solar system research such as: How pristine are comets? How does cometary activity work? Are the craters on comets from impacts or from other processes? What is the internal structure of cometary nuclei? How does cometary material look like and what is it made of? Are there internal heat sources that trigger normal activity and outbursts? What are the main physical and chemical processes in the coma? How does solar wind – comet interaction change at the different activity levels from 3 AU to perihelion? Are comets candidates that delivered prebiotic molecules and water to Earth?
Comets remain the poorest understood solar system objects. The future measurements of Rosetta orbiting around a comet for several months and delivering a lander to the surface will open a whole new field of research. And Rosetta will provide a much better understanding of comets and solar system formation, much as the Rosetta Stone did in our understanding of the Egyptian culture (Ref. 4).
NAVCAM (Navigation Camera): The Rosetta spacecraft uses a single camera with a 5º field of view and 12 bit 1024 x 1024 pixel resolution, allowing for visual tracking on each of the spacecraft approaches to the asteroids and finally to the comet.
Figure 5: Exploded view of major spacecraft components (image credit: ESA, AOES Medialab)
Table 2: Overview of some spacecraft parameters
Thermal louvers: Throughout its mission, the Rosetta spacecraft is exposed to extreme cold and hot temperatures. In the early and late stages of its prolonged expedition, the spacecraft will sweep across the inner Solar System, where sunlight is plentiful. However, in order to rendezvous with Comet 67P/Churyumov-Gerasimenko, Rosetta will have to probe beyond the asteroid belt, more than 5 times the Earth's distance from the Sun. In those frigid regions, the solar energy levels are only 4% of the those that we enjoy on our balmy planet. 12)
Since it is not feasible to wrap a spacecraft in multiple layers of warm clothing for periods of deep freeze, then strip these away when sunbathing is the order of the day, the ESA team has been obliged to come up with alternative ways of regulating temperature.
Designers have provided Rosetta with louvers — high-tech venetian blinds which control the spacecraft's heat loss. Lovingly polished by hand, these assemblies of thin metal blades must be handled like precious antiques, since any scratching, contamination or fingerprints will degrade their heat reflecting qualities.
The principle behind the louvers is quite simple. When Rosetta is cruising around the inner Solar System and basking in the warmth of the Sun, surface temperatures may soar to 130°C, and even internal equipment can reach 50°C. At such times, it is vital to stop the spacecraft from overheating, so the louvers are left fully open, allowing as much heat as possible to escape into space from Rosetta's radiators.
However, during its prolonged deep space exploration and comet rendezvous phases, when temperatures plummet to -150°C, heat conservation is the order of the day. Since the spacecraft's limited internal power supply - equivalent to the output from three ordinary light bulbs - then becomes the main source of warmth, it is essential to trap as much heat as possible. This means completely closing the louvers in order to prevent any heat from escaping.
Some 14 of these louver panels cover an area of 2.25 m2 on the Rosetta spacecraft, placed over its radiators across the side and back of the spacecraft. The louvers open and close on a fully passive basis, requiring no power to operate. Instead they work on a ‘bimetallic’ thermostat principle. The blades are moved by coiled springs made up in this case of a trio of different metals that expand and contract at differing rates, precisely tailored to rotate as required. Designed by Spain’s Sener company, the louvers were extensively tested by ESA’s Mechanical Systems Laboratory in advance of Rosetta’s 2004 launch. 13)
Figure 6: Photo of a louver panel (image credit: ESA–A. Le Floc'h)
Legend to Figure 7: Temperature control was a major headache for the designers of the Rosetta spacecraft. Near the Sun, overheating has to be prevented by using radiators to dissipate surplus heat into space. In the outer Solar System, the hardware and scientific instruments must be kept warm (especially when in hibernation) to ensure their survival.
Figure 8: Rosetta and Philae — the lander is attached to the orbiter during integration of the spacecraft (image credit: ESA)
Figure 9: Alternate view of the deployed Rosetta spacecraft showing in particular the solar array configuration (image credit: ESA, AOES Medialab)
Legend to Figure 9: Rosetta is the first spacecraft to journey beyond the main asteroid belt and rely solely on solar cells for power generation. The new solar-cell technology used on its two giant solar panels allow it to operate over 800 million km from the Sun, where light levels are only 4% of those on Earth.
Launch: The Rosetta spacecraft was launched on March 2, 2004 on Ariane 5G+ vehicle from Kourou, French Guinea.
Orbit and mission event overview:
The original target of the Rosetta mission was comet 46P/Wirtanen. A failure of an Ariane-5 rocket in December 2002 forced ESA to postpone the initially scheduled January 2003 launch and to re-target Rosetta, now heading for Comet 67P/Churyumov-Gerasimenko (Ref. 4).
Rosetta could not head straight for the comet. Instead it began a series of looping orbits around the Sun that brought it back for three Earth fly-bys and one Mars fly-by. Each time, the spacecraft changed its velocity and trajectory as it extracted energy from the gravitational field of Earth or Mars. During these planetary fly-bys, the science teams checked out their instruments and, in some cases, took the opportunity to carry out science observations coordinated with other ESA spacecraft such as Mars Express, Envisat and Cluster. 15)
During the 10 year trek across our solar system, Rosetta will travel five times the distance Sun-Earth, and will pass through the asteroid belt into deep space beyond 5 AU solar distance before it reaches its destination, the periodic comet 67P/Churyumov-Gerasimenko. On its way to 67P/Churyumov-Gerasimenko the spacecraft will employ four planetary gravity assist maneuvers (Earth-Mars-Earth-Earth) to acquire sufficient energy to reach the comet (Figure 10). Each of the fly-bys required months of intense preparation. In particular the fly-by of Mars in February 2007 was a critical operation: the new mission trajectory to 67P/Churyumov-Gerasimenko required that Rosetta fly past Mars at just 250 km from the surface, and spend 24 minutes in its shadow.
In between the last two Earth swingbys Rosetta will fly by the main belt asteroid 2867 Steins at a distance of 1700 km and at a relative velocity of 9 km/s on September 5, 2008. After the third Earth swingby Rosetta will enter the main asteroid belt again and fly by the main belt asteroid 21 Lutetia at a distance of 3000 km and a speed of 15 km/s on July 10, 2010. The spacecraft will enter a hibernation phase in July of 2011. In January 2014 Rosetta will come out of hibernation and begin a series of rendezvous maneuvers for comet 67P/Churyumov-Gerasimenko in May 2014.
The rendezvous maneuver 2 at~4.5 AU from the Sun will lower the spacecraft velocity relative to that of the comet to about 25 m/s and put it into the near comet drift phase, starting May 22, 2014 until the distance is about 10,000 km from the comet (Figure 3). It will be performed on the basis of a ground-based determination of the orbit from dedicated astrometric observations, before the comet is detected by the on-board cameras. The final point of the near-comet drift phase, the CAP (Comet Acquisition Point), is reached at a Sun distance of less than 4 AU. As soon as the spacecraft with a maximum relative velocity of about 1 m/s. The time and direction of the Rosetta-Philae separation will be chosen such that the landing package arrives with minimum vertical and horizontal velocities relative to the local (rotating) surface. After delivery of the lander on November 10, 2014 at a solar distance of 3 AU, the spacecraft will be injected into an orbit which is optimized for receiving the data transmitted from the lander and to relay them to the Earth. To adjust the payload operations sequences, the lander can be commanded via the orbiter.
Table 3: Milestones of the Rosetta mission
Figure 10: Rosetta's journey to 67P/Churyumov-Gerasimenko (image credit: ESA)
Figure 11: Schematic showing the spacecraft maneuvers close to comet 67P/Churyumov-Gerasimenko (image credit: ESA)
Sensor complement: (OSIRIS, ALICE, VIRTIS, MIRO, ROSINA, COSIMA, MIDAS, CONSERT, GIADA,RPC, RSI)
The Orbiter’s scientific sensor complement includes 11 experiments and a small Lander, which will conduct its own scientific investigations. Scientific consortia from institutes across Europe and the United States have provided these state-of-the-art instruments.
The instruments on the Rosetta Orbiter will examine every aspect of the small cosmic iceberg. Wide and Narrow Angle Cameras will image the comet’s nucleus to determine their volume, shape, bulk density and surface properties. Three spectrometers operating at different wavelengths will analyze the gases in the near-nucleus region, measure the comet’s production rates of water and carbon monoxide/dioxide, and map the temperature and composition of the nucleus (Ref. 4).
Our knowledge of the nucleus should be revolutionized by the CONSERT experiment, which will probe the comet’s interior by transmitting and receiving radio waves that are reflected and scattered as they pass through the nucleus. 16)
Four more instruments will examine the comet’s dust and gas environment, measuring the composition and physical characteristics of the particles, e.g. population, size, mass, shape and velocity. The comet’s plasma environment and interaction with the electrically charged particles of the solar wind will be studied by the Rosetta Plasma Consortium and the Radio Science Investigation.
Figure 12: The Rosetta spacecraft and its scientific payload (image credit: ESA) 17)
OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System)
Multi-color imaging with a WAC (Wide Angle Camera) and a NAC (Narrow Angle Camera) to obtain high-resolution images of the comet’s nucleus. PI: Holger Sierks, MPS (Max Planck Institute for Solar System Research), Katlenburg-Lindau, Germany.
The objective of the OSIRIS assembly is to observe the cometary rotation, and to study the physical and chemical processes that occur in, on, and near the cometary nucleus. It also maps the cometary morphology, which will help Rosetta’s lander (Philae) to find a suitable spot for setting down in the comet’s surface. -The strength of OSIRIS is the coverage of the whole nucleus and its immediate environment with excellent spatial and temporal resolution and the spectral sensitivity across the whole reflected solar continuum up to the onset of thermal emission. This provides a context for the interpretation of the results from Philae. 18) 19) 20)
The OSIRIS cameras were provided by a consortium of 9 institutes from 5 European countries and from ESA, under the leadership of the MPS . The participating institutes of the consortium are: MPS (Katlenburg-Lindau, Germany), LAM (Laboratoire d’Astrophysique de Marseille), Marseille, France; UPD (University of Padova), Padova, Italy; IAA (Instituto de Astrofísica de Andalucía ), Granada, Spain; University of Uppsala (Sweden); ESA/ESTEC, Noordwijk, The Netherlands; UPM (Universidad Politécnica de Madrid), Madrid, Spain; INTA (National Institute for Aerospace Technology),Madrid, Spain; IDA (Institute of Computer and Network Engineering at the TU Braunschweig),Braunschweig, Germany.
Figure 13: Photo of the OSIRIS cameras (image credit: MPS)
After the launch of Rosetta (March 2, 2004), OSIRIS was activated on several occasions before the arrival to the main target, comet 67P/Churyumov-Gerasimenko. It was commissioned in seven slots between March 2004 and June 2005, and it performed several important scientific observations:
• A monitoring campaign of comet 9P/Tempel 1 around the Deep Impact event on 4 July 2005
• The fly-by of asteroid 2867 Steins on 5 September 2008
• Two Earth swing-bys in Nov. 2007 and Nov. 2009
• The observation of the remnant of a collision between two main-belt asteroids in February 2010 - The flyby of asteroid 21 Lutetia on 10 July 2010
• Early observation of the comet from more than 1AU distance in March 2011.
Figure 14: Specification of the OSIRIS assembly
Science objectives: The OSIRIS science objectives for the comet nucleus, the gases and dust produced by the comet and for the asteroid flybys are:
Figure 15: Nucleus objectives of OSIRIS
Table 4: Dust objectives of OSIRIS
Table 5: Gas objectives of OSIRIS
Table 6: Asteroid flyby objectives of OSIRIS
Table 7: Mars and Martian satellites flyby objectives of OSIRIS
Table 8: Earth/Moon system flyby objectives of OSIRIS
ALICE (Ultraviolet Imaging Spectrometer)
Analyses gases in the coma and tail and measures the comet’s production rates of water and carbon monoxide/dioxide. ALICE is a NASA instrument providing UV spectroscopy in the band 70-205 nm. PI: Alan Stern, SwRI (Southwest Research Institute), Boulder, CO, USA. The ALICE UV spectrometer will analyze gases in the coma and the tail, and it measures the comet’s production rates of water and carbon monoxide or dioxide. It will also provide information on the surface composition of the nucleus. 21) 22)
Instrument: Light enters the Alice telescope through a 40 x 40 mm entrance aperture and is collected and focused by an off-axis paraboloidal primary mirror onto the approximately 0.1° x 6° spectrograph entrance slit. After passing through the entrance slit, the light falls onto the toroidal holographic grating of a Rowland Circle style imaging spectrograph, where it is dispersed onto a microchannel plate detector. The 2D (1024 x 32 pixel) format MCP detector uses dual, side-by-side, solar-blind photocathodes of potassium bromide (KBr) and cesium iodide (CsI). The predicted spectral resolving power (λ/Δλ) of Alice is in the range of 105 - 330 for an extended source that fills the instantaneous FOV (Field of View) defined by the size of the entrance slit. 23)
Table 9: Summary of ALICE characteristics 24)
VIRTIS (Visible and Infrared Thermal Imaging Spectrometer)
An imaging spectrometer that combines three data channels in one instrument. Two of the data channels are designed to perform spectral mapping. The third channel is devoted to spectroscopy. Maps and studies the nature of the solids and the temperature on the surface of the nucleus. Also identifies comet gases, characterizes the physical conditions of the coma and helps to identify the best landing sites. Provides VIS and IR mapping (spectroscopy) in the region 0.25-5 µm. PI: Angioletta Coradini, IAS-CNR, Rome, Italy. 25)
Instrument: The optical subsystems are housed inside a common structure - the cold box - cooled to 130 K by a radiative surface supported on a truss having low thermal conductivity. On the pallet supporting the truss, two sets of electronics and two cryogenic coolers for the detectors are mounted. The cold box is rigidly mounted on the pallet but thermally isolated from it. The pallet and cold box together form the optics module, which is mounted inside the spacecraft arranged so that the observing axes of the optical subsystems are normal to the nadir (comet) pointing wall of the spacecraft. The electronics module, containing the digital electronics and power supply, is mounted separately. 26)
The mapping channel optical system is a Shafer telescope matched through a slit to an Offner grating spectrometer. The Shafer telescope consists of five aluminum mirrors mounted on an aluminum optical bench. The primary mirror is a scanning mirror driven by a torque motor. The Offner spectrometer consists of a relay mirror and a spherical convex diffraction grating, both made of glass.
The mapping channel utilizes a silicon charge coupled device (CCD) to detect wavelengths from 0.25 µm to 1 µm and a mercury cadmium telluride (HgCdTe) infrared focal plane array (IRFPA) to detect from 0.95 µm to 5 µm. The IRFPA is cooled to 70 K by a Stirling cycle cooler. The cold tip of the cooler is connected to the IRFPA by copper thermal straps. The CCD is operated at 155 K and is mounted directly on the spectrometer.
The high resolution channel is an echelle spectrometer. The incident light is collected by an off-axis parabolic mirror and then collimated by another off-axis parabola before entering a cross-dispersion prism. After exiting the prism, the light is diffracted by a flat reflection grating, which disperses the light in a direction perpendicular to the prism dispersion. The low groove density grating is the echelle element of the spectrometer and achieves very high spectral resolution by separating orders seven through sixteen across a two-dimensional detector array.
The high-resolution channel employs a HgCdTe IRFPA to perform detection from 2 to 5 μm. The detector is cooled to 70 K by a Stirling cycle cooler.
Table 10: Summary of VIRTIS characteristics
• Aug. 1, 2014: ESA’s Rosetta spacecraft has made its first temperature measurements of its target comet, finding that it is too hot to be covered in ice and must instead have a dark, dusty crust. The observations were made by the VIRTIS instrument between 13 and 21 July, when Rosetta closed in from 14 000 km to the comet to just over 5000 km. 27)
• On 14 July, 2014, the entire surface of the comet occupied one of VIRTIS's pixels, allowing the scientists to estimate the mean temperature of the nucleus – around 205 K. While this may seem rather cold, it is somehow warmer than the scientists expected, providing the scientists with some first clues on the composition and the physical properties of the surface of the nucleus.
• July 8, 2014: First measurements of VIRTIS on board Rosetta have been probing the surface temperature on the nucleus of comet 67P/C-G. 28)
MIRO (Microwave Instrument for the Rosetta Orbiter)
The MIRO investigation addresses the nature of the cometary nucleus, outgassing from the nucleus and development of the coma as strongly interrelated aspects of cometary physics. During the flybys of the asteroids and, the MIRO instrument will measure the near surface temperature of these asteroids and search for outgassing activity in an effort to understand better the relationship between comets and asteroids.
PI: Sam Gulkis of NASA/JPL, Pasadena, CA. The MIRO investigation was conceived and designed functionally by the investigation team consisting of 19 scientists from 6 different institutions, and the MIRO project office, located at NASA/JPL.
Figure 16: Illustration of the MIRO instrument (image credit: MIRO Team)
The five objectives of the MIRO instrument are to: 29)
1) Characterize the abundances of major volatile species and key isotope ratios in the nucleus ices.
The MIRO instrument will measure absolute abundances of key volatile species - H2O, CO, CH3OH, and NH3 - and quantify fundamental isotope ratios - 17O,16O and 18O, 16O - in a region within several kilometers from the surface of the nucleus, nearly independent of orbiter to nucleus distance.
Water and carbon monoxide are chosen for observation because they are believed to be the primary ices driving cometary activity. Methanol is a common organic molecule, chosen because it is a convenient probe of gas excitation temperature by virtue of its many transitions. Knowledge of ammonia abundance has important implications for the excitation state of nitrogen in the solar nebula. By providing measurements of isotopic species abundances with extremely high mass discrimination, the MIRO experiment can use isotope ratios as a discriminator of cometary origins. The MIRO investigation will combine measurements of the variation of outgassing rates with heliocentric distance with models of gas votalization and transport in the nucleus to quantify the intrinsic abundances of volatiles within the nucleus.
2) Study the processes controlling outgassing in the surface layer of the nucleus.
The MIRO experiment will measure surface outgassing rates for H2O, CO, and other volatile species, as well as nucleus subsurface temperatures to study key processes controlling the outgassing of the comet nucleus.
The MIRO experiment will measure surface outgassing rates for H2O, CO, and other volatile species, as well as nucleus subsurface temperatures to study key processes controlling the outgassing of the comet nucleus.
3) Study the processes controlling the development of the inner coma. -MIRO will measure density, temperature, and kinematic velocity in the transition region close to the surface of the nucleus.
Measurements of gas density, temperature, and flow field in the coma near the surface of the nucleus will be used to test models of the important radiative and dynamical processes in the inner coma, and thus improve our understanding of the causes of observed gas and dust structures. The high spectral resolution and sensitivity will provide a unique capability to observe Doppler-broadened spectral lines at very low temperatures.
4) Globally characterize the nucleus subsurface to depths of a few centimeters or more.
The MIRO instrument will map the nucleus and determine the subsurface temperature distribution to depths of several centimeters or more. Morphological features on scales as small as 5 m will be identified and correlated with regions of outgassing.
The combination of global outgassing and temperature observations from MIRO and in situ measurements from the Rosetta lander will provide important insights into the origins of outgassing regions and of the thermal inertia of subsurface materials in the nucleus.
5) Search for low levels of gas in the asteroid environment.
The MIRO instrument will search for low levels of gas in the vicinity of asteroids and measure subsurface temperature to provide information on the presence of water ice, and on near surface thermal characteristics and the presence or absence of a regolith.
MIRO is configured both as a continuum radiometer and a very high spectral resolution line receiver. Center-band operating frequencies are near 190 GHz (1.6 mm) and 562 GHz (0.5 mm). The spatial resolution of the instrument, operating in the submillimeter band, is approximately 5 m at a distance of 2 km from the nucleus. The MIRO spectrometer is tuned to measure four volatile species - H2O, CO, CH3OH, and NH3 and the isotopes of water —H217O and H218O. These four species have all been measured to be present in comets. The spectral resolution is sufficient to observe individual, thermally broadened, line shapes at all temperatures down to 10 K or less. The MIRO experiment will use these species as probes of the physical conditions within the nucleus and coma. The basic quantities measured by MIRO are surface temperature, and gas abundance, velocity, and temperature of each species, along with their spatial and temporal variability. This information will be used to infer coma structure and outgassing processes, including the nature of the nucleus/coma interface. 30) 31)
Instrument: MIRO consists of an assembly of two heterodyne radiometers:
- Millimeterwave receiver (at 190 GHz , ~ 1.6 mm)
- Submillimeterwave receiver (at 562 GHz, 0.5 mm).
The mm and sub-mm radiometers are configured with a broadband continuum detector for the determination of the brightened temperature of the comet nucleus and the target asteroids. The sub-mm receiver is configured as a very high resolution spectrometer for the observation of the eight molecular transitions. The instrument is constituted of four separate physical modules, interconnected by a harness. The sensor unit is mounted on the spacecraft payload plane using the baseplate as the interface. The telescope boresight direction is aligned with the Rosetta payload line of sight. The optical bench is mounted on the undersite of the baseplate, under the telescope and inside the spacecraft. The mm and sub-mm wave receiver front ends, the calibration mechanism and the quasi-optics for coupling the telescope to the receivers are installed on the optical bench. The Sensor Backend Electronic Unit contains the intermediate frequency processor, the PLL (Phase Locked Loop) and the frequency sources. Due to his power consumption, it mounted next to a louvred radiator internal to the spacecraft. The Electronic Unit contains the CTS (Chirp Transform Spectrometer), including instrument computer and power conditioning circuits. The USO (Ultra Stable Oscillator) is self contained and thermally controlled. Those items are presented in Figure 17.
Table 11: Key parameters of MIRO
Figure 17: Block diagram of MIRO (image credit: MIRO Team)
MIRO post launch results: The MIRO instrument appears to be fully functional at the end of commissioning. The measured key parameters appear to be better than expected.
Table 12: Key parameters were measured using the Earth as target, they are summarized in this table
ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis)
Comets are believed to be the most pristine bodies in the solar system. They were created 4600 million years ago far away from the sun and have remained for most of the time of their existence far outside of Pluto’s orbit. They are small enough to have experienced almost no internal heating. They therefore present a reservoir of well-preserved material from the time of the Solar System’s creation. They offer clues to the origin of the Solar System’s material and to the processes that led from the solar nebula to the formation of planets. In contrast to meteorites (the other primitive material available for investigations), comets have retained the volatile part of the solar nebula. Several interesting questions on the history of the Solar System materials can therefore be answered only by studying comets. In particular, the composition of the volatile material — the main goal of the ROSINA instrument.
ROSINA is the main mass spectrometer on the orbiter of ESA’s Rosetta mission to comet 67P/Churyumov-Gerasimenko. It consists of two mass spectrometers for neutrals and ions. ROSINA’s primary objective is to determine the basic properties of the gas in the comet’s atmosphere and ionosphere such as composition, temperature and velocity. 32) 33) 34) 35)
The ROSINA research team comes from many institutions: Physical Institute, University of Bern, Bern Switzerland; BIRA (Belgian Institute for Space Aeronomy), Brussels, Belgium; CESR (Centre d'Etude Spatiale des Rayonnements), Toulouse, France; IPSL (L'Institut Pierre Simon Laplace), Saint Maur, France; Lockheed Martin Advanced Technology Center, Palo Alto, CA, USA; MPS (Max Plack Institute for Solar System Research), Katlenburg-Lindau, Germany; Technische Universität Braunschweig, Germany; University of Michigan, Ann Arbor, MI, USA; SwRI (Southwest Research Institute), San Antonio, TX, USA; University of Giessen, Giessen, Germany. PI: Kathrin Altwegg,Hans Balsiger (honorary PI), University of Bern, Switzerland.
Science objectives: ROSINA’s main goal is to determine the elemental, isotopic, and molecular composition of the comet’s atmosphere and ionosphere. In addition, the scientists are interested in the temperature and the bulk velocity of the gas as well as the reactions of the gas and ions with the dust emitted by the comet. These results may render important implications for questions regarding the origin of comets, the relation between cometary and interstellar material, and the origin and evolution of the Solar System.
To accomplish these demanding objectives, ROSINA has unprecedented capabilities:
• A wide mass range from 1 amu (atomic mass unit) to more than 300 amu. This makes it possible to detect light atoms such as hydrogen as well as heavy organic molecules.
• A high mass resolution of more than 3000 m/Δm. This means that ROSINA is, for example, able to resolve CO from N2 and 13C from 12CH.
• A wide dynamic range of 1010
• High sensitivity (more than 10-5 A/mbar) to accommodate large differences in ion and neutral gas concentrations and severe changes in the ion and gas flux as the comet’s activity develops between aphelion and perihelion.
Instrument: ROSINA consists of two mass spectrometers for neutrals and primary ions with complementary capabilities and a pressure sensor. The total mass of the ROSINA assembly is 36 kg with a power consumption of 53 W max.
• The DFMS (Double Focusing Magnetic mass Spectrometer) has a mass range from 1 amu to 150 amu and a mass resolution of 3000 at 1 percent peak height. It is optimized for very high mass resolution and a large dynamic range.
• The RTOF (Reflectron Time Of Flight) mass spectrometer with a mass range from 1 amu to more than 300 amu and a high sensitivity.
• The two pressure gages, COPS (COmet Pressure Sensor), provide density and velocity measurements of the cometary gas.
Figure 18: Photo of the ROSINA DFMS (Double Focusing Mass Spectrometer), Image credit: University of Bern
Figure 19: Photos of the ROSINA RTOF instruments (image credit: MPS)
Figure 20: Photo of the COPS devices (image credit: University of Bern)
COSIMA (Cometary Secondary Ion Mass Analyzer)
The instrument will analyze the characteristics of dust grains emitted by the comet, including their composition and whether they are organic or inorganic. COSIMA is a dust mass spectrometer (SIMS, m/µm ~2000). COSIMA was built by a consortium led by the MPS (Max Planck Institute for Solar System Research), Katlenburg-Lindau, Germany - in collaboration with Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, CNRS, Université d’Orléans, France; Institut d'Astrophysique Spatiale, CNRS, Université Paris Sud, Orsay, France; FMI (Finnish Meteorological Institute), Helsinki, Finland; Universität Wuppertal, Wuppertal, Germany; von Hoerner und Sulger GmbH, Schwetzingen, Germany; Universität der Bundeswehr, Neubiberg, Germany; Institut für Physik, Forschungszentrum Seibersdorf , Seibersdorf, Austria; Institut für Weltraumforschung, Österreichische Akademie der Wissenschaften, (Graz, Austria; PI: Martin Hilchenbach, (formerly Jochen Kissel), MPS. 36) 37)
COSIMA is a secondary ion mass spectrometer equipped with a dust collector, a primary ion gun, and an optical microscope for target characterization. Dust from the near comet environment is collected on a target. The target is then moved under a microscope where the positions of any dust particles are determined. The cometary dust particles are then bombarded with pulses of indium ions from the primary ion gun. The resulting secondary ions are extracted into the time-of-flight mass spectrometer.
Science objectives: COSIMA will perform in-situ measurements on individual dust particles emitted by the target comet and collected by COSIMA dust collector subsystem. From the resulting data it will be possible to determine:
• The elemental composition of solid cometary particles to characterize comets in the framework of the solar system chemistry
• The isotopic composition of key elements in solid cometary particles such as H, C, Mg, Ca, Ti in order to establish boundary conditions for models of the origin and evolution of comets and thereby of the solar system
• The chemical states of the elements
• Variations of the chemical and isotopic composition between individual particulate components
• Changes in composition that occur as functions of time ("short-term variations") and orbital position
• The variability of the composition of different comets by comparing the results to those obtained previously from comet Halley
• The presence of an organic component that is not associated with a rocky phase
• The molecular composition of the organic phase of the solid cometary particles
• The molecular composition of the inorganic phase of the solid cometary particles
• The chemical state of the organic matter characterized by its saturation degree oxidation state and bond types.
Instrument: The core of the COSIMA instrument is a TOF (Time of Flight) secondary SIMS (Ion Mass Spectrometer) equipped with a dust collector, a primary ion gun, and an optical microscope (COSISCOPE) for target characterization. Once one of the targets on the target wheel has been exposed to cometary dust it is moved in front of the microscope and imaged under shallow angle illumination provided by light emitting diodes. On-board image evaluation detects the presence and location of dust particles with diameters exceeding a few µm and calculates their position relative to the target reference point. Once the presence of features of interest is established, the target is moved in front of the mass spectrometer. Three nanosecond duration pulses of indium-115 with an energy of 10 keV and about 10 µm in diameter from the primary ion gun hit the selected feature. Secondary ions from the cometary matter are extracted by the SIL (Secondary Ion extraction Lens) into the TOF section. After passing deflection plates for beam steering the ions travel through a field free section. Next they pass a two stage reflector, return through the drift section to the ion detector. Its main element is a single stage microsphere plate, where the ions are detected. The arrival time of each ion is measured with an accuracy of about 2 ns.
Precision in the timing of the primary ion pulses, the correct selection of the dimensions and the voltages of the mass spectrometer and the accurate measurement of the secondary ion flight time are needed to obtain high mass resolution in the COSIMA instrument. A mass resolution of 2000 is achieved for ions having a flight time of 16 µs, which occurs for ion masses of above 28 Daltons (atomic mass units).
Figure 21: Photo of the COSIMA flight model (image credit: MPS)
Operations: Since launch and commissioning, the instrument health has been monitored in checkouts every 6 months. The instrument proved to be in good health during the checkouts performed so far. Operations have included mechanism tests, instrument calibration, ion source maintenance, and interference check between COSIMA and other instruments. The instrument will be re-commissioned in April and July 2014, just before the science phase of Rosetta at comet 67P/Churyumov-Gerasimenko.
• Sept. 8, 2014: The COSIMA team presented an image of the first dust grains collected by the COSIMA instrument when Rosetta was at a distance of less than 100 km from the nucleus of comet 67P/Churyumov-Gerasimenko. On Aug. 11, the first of COSIMA’s 24 target plates were exposed to space. On Aug. 24, when the COSIMA team took a look at the image of the plate, they saw a number of large dust grains from the comet on a target that had been pristine when examined one week before. A first examination of the plate indicates that the largest two grains are about 50 µm and 70 µm in width, comparable to the width of a human hair. 38) 39)
• August 8, 2014: Now that comet 67P/Churyumov-Gerasimenko is within reach, Rosetta’s mass spectrometer COSIMA, is beginning to reach for cometary dust. 40)
• In early April 2014, the project uploaded new software, and after switching the COSIMA instrument off and then back on, the previous tests proved successful and COSIMA was up and running with a fresh memory. On their way to or from the spacecraft, these data travel about 40 minutes through the inner Solar System. 41)
MIDAS (Micro-Imaging Dust Analysis System)
MIDAS is designed to collect and image dust particles collected in the vicinity around the comet. The measurement principle is based on atomic force microscopy. This technique allows for true three-dimensional imaging at nanometer-scale resolution. The instrument is built to investigate the smallest grain size fraction released from the comet's surface; it will also investigate the structural complexity of grain cluster up to a few µm. More than 60 collector facets, which can be individually exposed into the dust stream, and a total of 16 imaging sensors, guarantee continuous observations throughout the mission lifetime. 42)
Scientific objectives: Dust particles emitted from comet nuclei form a major source of information for the understanding of primitive matter in our Solar System. It represents remnant material from the early times of the formation comets, asteroids and planets some 4.5 billion years ago. The prime scientific objective of the MIDAS experiment is to image the micro-topography and micro-textural units of cometary dust particles; this provides important information about the characteristics and nature of these particles, for example, about the composition of their primary building blocks. In addition, sub-features on clean crystal surfaces provide insight into either the growth conditions (twinning, screw dislocations) and/or storage environment conditions (dissolution marks).
Following the mapping of single particles with a resolution in the few nanometer range, many statistical parameters describe the cometary environment. This comprises the statistical evaluation of the collected particles according to size, volume and shape, but also temporal and spatial variations of the particle flux can be deduced.
In summary, MIDAS will meet the scientific objectives that have been established for this instrument when the following information can be obtained during the rendezvous with the comet:
• 3D images of single particles with a resolution better than 10 nm
• Search for "very small particles" (10 nm)
• Search for evidence of euhedral (well-formed, sharp-faced) crystals
• Possible detection of ferro-magnetic minerals
• Size distribution of particles
• Variation of particle fluxes on time scales between hours and days.
The instrument was developed by an international collaborative team led by IWF (Institut für Weltraumforschung - Space Research Institute), Graz, Austria; ESA/ESTEC, Noordwijk, The Netherlands; Physics Department of the University of Kassel, Germany; Institute of Applied Systems Technology of Joanneum Research, Graz, Austria; Austrian Research Centers Seibersdorf (now Ruag Space, Vienna); Vienna University of Technology, Vienna, Austria. PI: Mark Bentley, IWF, Graz, Austria. 43) 44)
Instrument: Dust grains in the size range from 4 µm down to 4 nm will be imaged in three dimensions by means of atomic force microscopy (AFM). AFM makes use of tiny physical forces (van der Waals, interatomic, magnetic, etc.) that act on a sensor in closest distance to a surface.
The sensor is a 600 µm long cantilever arm with an extremely sharp 7 µm long tip mounted underneath. The sensor is controlled by a piezoelectric mechanical system that scans above the surface and senses its topography. The dust particles enter the instrument via a funnel penetrating the spacecraft's hull and hit the collector surface. Sixty-four of these targets (coated silicon facets) are mounted on the perimeter of the dust collector wheel. The facet exposed to the dust stream is rotated and presented to the microscope, which approaches the surface automatically and starts the scanning (imaging) process.
Figure 22: Photo of the MIDAS instrument, inside view (left) and flight model (right), image credit: IWF
Table 13: Performance parameters of the MIDAS instrument
In the test sequence of the MIDAS instrument, which ran over five contact passes from the ground station to the spacecraft, the following results were obtained:
- Complete electronics checkout
- Cover opening by a pyrolytic device
- Unlocking of all clamp mechanisms
- Movement of linear stage and approach mechanism out of launch position
- Verification of all motors and mechanisms
- Verification of all 16 sensors by resonance search
- Verification of the scanner by imaging calibration surfaces
- Initial characterization of mechanical noise environment.
The overall result of the MIDAS commissioning phase and subsequent instrument checkout demonstrated full functionality and performance of the instrument up to the moment the spacecraft (and payload) was put into hibernation in June 2011.
CONSERT (Comet Nucleus Sounding Experiment by Radiowave Transmission)
CONSERT is a time domain transponder that operates between one module that will land on the comet surface and another that will orbit the comet. A radio signal is transmitted from the orbiting component of the instrument and passes through the comet nucleus to the component on the comet surface. The signal is received on the lander, where some data is extracted, and then immediately re-transmitted back to the orbiter, where the main experiment data collection occurs. The variations in phase and amplitude that occur as the radio waves pass through different parts of the cometary nucleus will be used to perform tomography of the nucleus and determine the dielectric properties of the nuclear material. 45) 46) 47)
The overall science objective of the CONSERT investigation is to gather information about the geometrical structure and electrical properties of the deep interior of the comet nucleus. Inferences about the composition of the interior of the comet will then be made from the measured electrical properties. The main scientific objectives are:
• To measure the mean dielectric properties and, through modelling, to set constraints on the cometary composition (like material and porosity)
• To detect large-scale embedded structures (several tens of meters), and stratifications
• To detect small scale irregularities within the comet.
CONSERT probes the comet’s interior by studying radio waves that are reflected and scattered by the nucleus. The CONCERT instrument provides radio sounding and nucleus tomography. The instrument's mass is limited to 3 kg. PI: Wlodek Kofman, LPG (Laboratoire de Planetologie de Grenoble), CNRS/UJF, Grenoble, France.
Instrument: CONSERT works as a time domain transponder. The indirect and apparently complicated transponding procedure reduces the required accuracy of the clocks on the Orbiter and Lander, and makes it possible to stay within the constraints on mass and power consumption imposed on the space experiment. The CONSERT experiment on the orbiter and on the lander both consist of a transmit/receive antenna and a transmitter and receiver contained in a common box.
A 90 MHz radio signal, phase modulated with pseudo-randomly encoded data is transmitted from the orbiter towards the comet. The transmission lasts about 25 µs. The signal propagates through the comet nucleus and is received on the lander. The transmission cycle is repeated every 200 ms. The received signal is digitised and accumulated in the lander in order to increase the signal to noise ratio. Once the accumulation is finished, the signal is compressed to obtain a time/space resolution corresponding to 100 ns which corresponds to about 20 m in the comet. After the signal processing on the lander, which determines the position of the strongest path, the lander transmits the same pseudo-random code with a delay corresponding to that of the strongest path. The transmission cycle again lasts about 25 microseconds. The signal propagates back to the orbiter along virtually the same path, since the orbiter does not travel far during the measurement cycle. The signal is received on the orbiter, accumulated and stored in the memory in order to be sent to Earth. A complete measurement cycle lasts about 1 s.
GIADA (Grain Impact Analyzer and Dust Accumulator)
GIADA will measure the number, mass, momentum and velocity distribution of dust grains in the near-comet environment. GIADA will analyze both grains that travel directly from the nucleus to the spacecraft and those that arrive from other directions having had their ejection momentum altered by solar radiation pressure. 48) 49) 50)
GIADA is a contamination monitor providing dust velocity and impact momentum measurement. PI: Luigi Colangelo, INAF, Naples, Italy.
The primary scientific objectives of GIADA are:
• Dust flux measurement for "direct" and "reflected" grains: Two populations of cometary grains exist: "direct" (coming directly from the nucleus) and "reflected" grains (coming from the Sun direction, under the action of the solar radiation pressure). The two populations undergo very dissimilar dynamic evolution in the coma and have different times of ejection from the nucleus. In the case of Rosetta, "direct" and "reflected" grains can be collected simultaneously. The relative amount will depend on the probe position along its orbit. GIADA will be able to monitor grain fluxes coming from different directions and will allow, for the first time, discrimination between the two dust populations. This task is fundamental to the determination of the original dust size distribution. In turn, this information is required to define the dust mass loss rate.
• Analysis of the dust velocity distribution : The dust ejection velocity depends both on the grain size and on time. Moreover, grains with a given size have a wide dust velocity distribution. GIADA will allow the measurement of scalar velocity and momentum for grains coming from the nucleus direction so as to give mass and impact velocity of each analyzed "direct" grain. From this information it will be possible to derive grain mass and ejection velocity from the nucleus surface. For the first time we will obtain:
- the size dependence of the dust ejection velocity
- the relation between most probable dust velocity and dust mass
- the velocity distribution for each dust mass
- the link between velocity dispersion and dust mass.
• Study of dust evolution in the coma : Once ejected from the nucleus, grains may change their physical properties due to several processes, including, for example, fragmentation. These modifications may alter the grain size distribution. The size distribution of grains collected by GIADA in the nucleus direction should not be affected by the dust velocity dispersion. Thus, changes in the dust distribution at different nucleus distances can be linked directly to actual variations in the dust size distribution and correlation can be found with dust fragmentation and/or with emission from active areas on the nucleus.
• Correlation of dust changes with nucleus evolution and emission anisotropy : The dust environment characteristics depend on the comet-Sun distance and on the time evolution of the nucleus. The continuous monitoring by GIADA of dust flux and dynamic properties will offer the best opportunity to characterize the time evolution of the dust environment as a function of heliocentric distance. Nucleus imaging will allow us to link observed changes to the nucleus evolution and to its spin state.
• Determination of dust to gas ratio : One of the crucial parameters characterizing the comet nucleus is the dust to gas ratio. Dust flux monitoring by GIADA is needed to estimate the dust to gas ratio. This will be possible in combination with results of other experiments.
• Other objectives : The data provided by GIADA about dust fluxes and grain dynamic properties are very important for the correct interpretation of images of the coma and nucleus and mass spectrometer data. GIADA will help in the selection of the surface science package landing site. The characterization of dust emitting areas, and possibly of the dust population of different active areas, will be necessary for the site selection process to achieve a proper balance between safety and scientific interest.
GIADA will play an important role for the health and the safety of various experiments and the spacecraft itself, as it will be able to provide information about dust flux in several directions. Optical surfaces of experiments and other devices pointing to the nucleus will be polluted by the dust flux. GIADA data will allow the prediction of deposition rates and informed decision making for mission planning and operations. Data from GIADA will be the only resource to predict and allow control of the performance degradation of critical devices such as passive radiators and solar panels.
Instrument: The instrument comprises three modules: GIADA 1 measures momentum, scalar velocity and mass of single grains entering the instrument by the GDS (Grain Detection System) and the IS (Impact Sensor), placed in cascade. The GIADA 2 module contains the MBS (Micro Balances System); it controls the acquisition of data from the sensors and the operation of the other subsystems. It also provides the power supply for the whole experiment. The GIADA 3 module measures the cumulative dust flux and fluence from different directions by means of five microbalances. One microbalance points towards the nucleus, while the other four cover the widest possible solid angle. 51)
In the GDS, four laser diodes with their foreoptics are used to form a thin (3 mm) light curtain (100 cm2). For each grain passing through it, the scattered/reflected light is detected by two series of four detectors (photodiodes) placed at 90º with respect to the sources. In front of each photodiode a Winston cone is placed to achieve a uniform sensitivity in the detection area.
The IS is a thin (0.5 mm) aluminum square diaphragm (sensitive area 100 cm2) equipped with five piezoelectric sensors, placed below the corners and its center. When a grain impacts the sensing plate, flexural waves are generated on the plate, and are detected by the piezoelectric crystals. The maximum displacement of these systems is directly proportional to the impulse imparted, and the displacement of the crystal produces a proportional potential. Through calibration, a known impulse may be equated with a specific charge produced on the electrodes of the PZT crystals. The detected signal is proportional to the momentum of the incident grain through the factor (1+e), where e is the coefficient of restitution.
When a grain enters GIADA 1, the GDS gives a first estimate of the grain speed and starts a time counter that is stopped when the IS detects the grain impact and the momentum is measured. In this way, for each entering grain, speed, TOF (Time of Flight), momentum and, therefore, mass are measured.
The microbalances in GIADA 3 each consist of two quartz crystals oscillating at a frequency of about 15 MHz, one acting as a sensor, the other as a reference. The measured physical quantity is the beat frequency between the two crystals. The resonance frequency of the sensor quartz oscillator, exposed to the dust environment, changes due to the variation of its mass as a result of material accretion, while the reference crystal is not exposed to the dust flux. Thus, the output signal is proportional to the mass deposited on the sensor and dust flux and fluence are measured in time. The use of a reference crystal ensures extremely small dependence on temperature and power supply fluctuations and, thus, high sensitivity.
Figure 23: Two views of the GIADA instrument (image credit: INAF)
RPC (Rosetta Plasma Consortium)
Six sensors measure the physical properties of the nucleus; examine the structure of the inner coma;monitor cometary activity; and study the comet’s interaction with the solar wind. The RPC assembly consists of:
- Langmuir Probe (LAP). PI: Anders Eriksson (formerly Rolf Boström), IRF Uppsala, Sweden
- Ion and Electron Sensor (IES). PI: Jim Burch, SRI, San Antonio, TX, USA
- Flux Gate Magnetometer (MAG). PI: Karl-Heinz Glassmeier, IGEP, Braunschweig, Germany
- Ion Composition Analyzer (ICA). PI: Rickard Lundin, IRF, Kiruna, Sweden
- Mutual Impedance Probe (MIP). PI: Jean-Gabriele Trotignon, LPCE/CNRS, Orleans, France
- Plasma Interface Unit (PIU). PI: Chris Carr, Imperial College, London, UK.
• The physical properties of the cometary nucleus and its surface. Emphasis will be given to determination of the electrical properties of the crust, its remnant magnetization, surface charging and surface modification due to solar wind interaction, and early detection of cometary activity.
• The inner coma structure, dynamics, and aeronomy. Charged particle observation will allow a detailed examination of the aeronomic processes in the coupled dust-neutral gas-plasma environment of the inner coma, its thermodynamics, and structure such as the inner shocks.
• The development of cometary activity, and the micro- and macroscopic structure of the solar-wind interaction region as well as the formation and development of the cometary tail.
In order to realize these investigations extensive in-situ monitoring of the plasma electrons and ions, their composition, distribution, temperature, density, flow velocity, and the magnetic field will be necessary. These measurements will improve the understanding of the coupling processes of cometary dust, gas, and plasma as well as its interaction with the solar wind. The plasma and fields measurements thus provide complementary information to that of other Rosetta instruments for a deeper understanding of the overall physics and chemistry of an active comet.
The flybys of asteroid Steins and asteroid Lutetia have provided an opportunity to study in detail the physics of the solar wind - asteroid interaction. RPC has excellent capabilities for the investigation of this interaction. It has also been possible to study the magnetic and electric conductivity properties of the asteroids.
ICA (Ion Composition Analyzer): ICA measures the three-dimensional velocity distribution and mass distribution of positive ions. The mass resolution is sufficient to differentiate between the major particle species such as protons, helium, oxygen, molecular ions, and heavy ion clusters (dusty plasma). The ICA comprises an electrostatic arrival angle filter, a hemispherical electrostatic analyzer employed as an energy filter, and a magnetic deflection momentum filter. Particles are detected using a large micro channel plate and a two-dimensional anode array.
IES (Ion and Electron Sensor): The IES will simultaneously measure the flux of electrons and ions in the plasma surrounding the comet over an energy range from around one electron volt, which approaches the limits of detectability, up to 22 keV. IES consists of two electrostatic analyzers, one for electrons and one for ions, which share a common entrance aperture. The charged particle optics for IES employs a toroidal top-hat geometry along with electrostatic angle deflectors to achieve an electrostatically scanned field of view of 90º x 360º. 54)
LAP (Langmuir Probe): The LAP instrument will measure the density, temperature and flow velocity of the cometary plasma. It comprises two spherical sensors mounted at the tip of deployable booms, with the sensors capable of being swept in potential to measure the current-voltage characteristic of the intervening plasma, which provides information on the electron number density and temperature. The probes can be held at a fixed bias potential to measure plasma density fluctuations and by a time-of-flight analysis of the signals from the two probes the plasma flow velocity can be determined. 55)
MAG (Flux Gate Magnetometer): The MAG will measure the magnetic field in the region where the solar wind plasma interacts with the comet. It consists of two triaxial fluxgate magnetometer sensors mounted on a 1.5 m deployable boom that points away from the comet nucleus. One sensor is mounted near the outboard tip of the boom and one is mounted part way along the boom. The use of two sensors allows the effects of the spacecraft's own magnetic field to be minimized. MAG will also study any magnetic field possessed by the comet nucleus, in cooperation with the ROMAP magnetometer experiment on the Rosetta lander.
MIP (Mutual Impedance Probe): MIP will derive the electron gas density, temperature, and drift velocity in the inner coma of the comet by measuring the frequency response of the coupling impedance between two dipoles. MIP will also investigate the spectral distribution of natural waves in the 7 kHz to 3.5 MHz frequency range and monitor the dust and gas activity of the nucleus.
PIU (Plasma Interface Unit): PIU acts as an interface between the five instruments that make up RPC and the Rosetta spacecraft by providing a single path for the transmission of scientific and housekeeping data to the ground and for the receipt and processing of commands sent from the ground. The PIU also takes power from the spacecraft and converts, conditions and manages it for the RPC instruments. PIU also performs on-board data processing for the MAG sensor unit, which has no data processing capability of its own. 56)
RSI (Radio Science Investigation)
RSI makes use of the communication system that the Rosetta spacecraft uses to communicate with the ground stations on Earth. Either one-way or two-way radio links can be used for the investigations. In the one-way case, a signal generated by an ultra-stable oscillator on the spacecraft is received on Earth for analysis. In the two way case, a signal transmitted from the ground station is transmitted back to Earth by the spacecraft. In either case, the downlink may be performed in either X-band or both X-band and S-band. — PI: Martin Pätzold, University of Cologne, Germany. 57)
The goal of RSI is to investigate the nondispersive frequency shifts (classical Doppler) and dispersive frequency shifts (due to the ionized propagation medium), the signal power and the polarization of the radio carrier waves. Variations in these parameters will yield information on the motion of the spacecraft, the perturbing forces acting on the spacecraft and the propagation medium.
Science objectives: Doppler data provide time-resolved measurements of the spacecraft motion and the plasma state and thus may be used for physical investigation of the nucleus and the inner coma of the comet. In particular, the following scientific objectives may be addressed by an analysis of dual-frequency one-way or two-way radiometric tracking data, together with information provided by other Rosetta experiments, for example the remote imaging system (OSIRIS):
• Gravity Field and Dynamics
- Cometary mass and bulk density
- Cometary gravity field coefficients
- Cometary moments of inertia and spin state
- Cometary orbit, light shift, thermal properties of the nucleus
- Asteroid mass and bulk density
• Cometary Nucleus
- Size and shape (from spacecraft occultation observations)
- Internal structure (from nucleus sounding)
- Internal structure (from nucleus sounding)
- Rotation, precession and nutation rates (from bistatic radar)
• Cometary Coma
- Distribution of mm - dm size particles (from coma sounding)
- Plasma content of the inner coma (from coma sounding)
- Gas and dust mass flux (from non-gravitational perturbations of the spacecraft)
• Solar Corona Science
- Electron content of the inner corona, solar wind acceleration, search for coronal mass ejections, turbulence.
Instrument: The two-way radio link is established by transmitting an uplink radio signal either at S-band or X-band to the spacecraft. The received uplink carrier frequency is transponded to downlinks at X-band and S-band upon multiplying by the constant transponder ratios 240/221 and 880/221, respectively, in order that the ratio of the two downlinks is 880/240 = 11/3. This radio mode takes advantage of the superior frequency stability inherent to the hydrogen maser in the ground station on Earth. This mode is used for all RSI gravity science applications, routine tracking observations when in orbit during the escort phase, and for the sounding of the solar corona.
The one-way radio link is used only during an occultation of the spacecraft by the nucleus as seen from Earth. This enables radio sounding of the immediate vicinity of the nucleus and perhaps even the nucleus itself, should the solid cometary body prove to be penetrable by microwaves. These one-way occultation experiments require an USO (Ultra-Stable Oscillator) added to the radio subsystem. The prime purpose of the USO is to serve as a phase-coherent frequency reference for the simultaneous one-way downlink transmissions at S-band and X-band. The required stability (Allan variance) of the USO is about Δf/f ~10-13 at 10-1000 seconds integration time. The one-way radio link can be transmitted either while receiving a non-coherent uplink or without any uplink contact at all.
Ground segment: Ground stations include antennas, associated equipment and operating systems in the tracking complexes of Perth (ESA, 35 m), Australia, and the DSN (Deep Space Network) of NASA, (34 m) in California, Spain and Australia. A tracking pass consists of typically eight to ten hours of visibility. Measurements of the spacecraft range and carrier Doppler shift can be obtained whenever the spacecraft is visible. In the two-way mode the ground station transmits an uplink radio signal at S-band (if the spacecraft receiver operates at S-band) or at X-band and receives the dual-frequency simultaneous downlink at X-band and S-band. The information about signal amplitude, received frequency and polarization is extracted and stored as a function of ground receive time.
SREM (Standard Radiation Environment Monitor)
In addition to these scientific experiments the orbiter is also equipped with a SREM device to monitor the high energetic, ionizing particle environment aboard the spacecraft. The objective of SREM is to provide a continuous, almost uninterrupted measurement of the high energetic particles encountered by Rosetta and provide this information for mission analysis purposes.
Philae (Rosetta Lander)
The Rosetta lander Philae can be considered a scientific spacecraft of its own that is carried and delivered by the Rosetta orbiter to the comet. Upon proposal by various scientists, lead by Helmut Rosenbauer from the MPS (Max Planck Institute for Solar System Research) in Katlenburg-Lindau, the 10 scientific instruments and the various spacecraft subsystems are provided by a consortium of spaceflight agencies and research institutes from 6 European countries and by ESA. The Philae lander is provided by a consortium led by DLR, MPS, CNES and ASI. DLR played a major role in building the lander and runs the LCC (Lander Control Center) at DLR Cologne, which is preparing for and overseeing the difficult task of landing on the comet, a feat never before accomplished. 58) 59) 60) 61) 62) 63)
The goal of Philae's mission is to land successfully on the surface of a comet, and transmit data from the surface about the comet's composition. The scientific goals of the mission focus on "elemental, isotopic, molecular and mineralogical composition of the cometary material, the characterization of physical properties of the surface and subsurface material, the large-scale structure and the magnetic and plasma environment of the nucleus.”
The SONC (Science Operations and Navigation Center) is located at CNES in Toulouse, France. Both centers are directly connected to the RMOC (Rosetta Mission Operations Center) at ESOC, Darmstadt. The Rosetta science operations planning is performed at the RSGS (Rosetta Science Ground Segment) at ESAC, near Madrid. - The responsibility for the Lander delivery lies at ESA. However, close cooperation between the partners is envisaged, to reach the challenging task of the first successful landing on a comet. 64)
Figure 24: Artist’s impression of the 100 kg Philae lander (image credit: ESA, DLR)
The Philae lander is designed to touch down on the comet's surface after being deployed from the main spacecraft body and "falling" from a height of 25 km at about 1 m/s towards the comet along a ballistic trajectory. Upon contact, it will deploy two harpoons to anchor itself to the surface, and the legs are designed to dampen the initial impact to avoid bouncing, because the comet's escape velocity is only around 0.5 m/s.
Communications with Earth will use the orbiter spacecraft as a relay station to reduce the electrical power needed. The mission duration on the surface is planned to be at least one week, but an extended mission lasting months is possible.
Rosetta-Philae RF link: The transceiver is a full duplex S-band transmission set for digital data developed specifically for space applications. The conception made by Syrlinks was done with drastic objectives for mass and power consumption. For this, the use of commercial parts was decided leading to a low cost product widely used afterwards on the Myriade platform family. The transceiver is composed of a transmitter, a receiver and a reception filter for dual antenna use (Figure 25). The filter protects the receiver from out-of-band signals, particularly from the transmitter. The two functions (receiver and transmitter) are fully independent and can be activated separately. Technical details are given in the Table 14 and an illustration in Figure 26. 65) 66)
Figure 25: Rosetta-Philae bidirectional RF link (image credit: CNES, Syrlinks)
Table 14: Transceiver technical specification
There are two transceivers on both sides of the RF link. The redundancy is activated with RF switches on orbiter side (1 Tx/1 Rx active) and with diplexer on lander side (1 Tx/2 Rx active). The choice of implementing identical RF chains for transmission and reception on the orbiter and the lander has given great advantages, such as cutting procurement costs and simplifying qualification, integration and testing.
With 1W RF output power and 1 dBi gain (@ 60º) patch antennas, link establishment is possible for distances up to 150 km.
Figure 26: Photo of the Rosetta ISL transceiver (image credit: Syrlinks)
The lander telecommunication system answers to a request-to-send protocol from the orbiter at any time. This handshake protocol, which implies full duplex equipment and which was specifically designed for Rosetta mission ensures a desired quality of transmission even when the relative geometry and visibility between the orbiter and the lander is not favorable.
In the housekeeping telemetry available at orbiter side, one parameter is particularly interesting to get information beyond its intrinsic value: the RSSI (Received Signal Strength Indicator). From this raw telemetry value, it is possible to extract the received power level on orbiter side, which can be then processed.
Lander bus: The main structure of the lander is made from carbon fiber, shaped into a plate maintaining mechanical stability, a platform for the science instruments, and a hexagonal "sandwich" to connect all the parts. The main body rests on a tripod landing gear, with ice screws and sensors integrated in the feet. All instruments and the drill are depicted in their deployed configuration. The open face of Philae with instruments exposed to the cometary environment is colloquially termed “balcony”.
The total mass is about 100 kg. Its "hood" is covered with solar cells for power generation.
Battery assembly: The lander energy storage is based on two types of sources: primary batteries for short term activities (1000 Wh), secondary batteries for long term activities(140 Wh). The assembly includes the associated electronics.
Figure 27: A schematic view of the Philae spacecraft with the extended lander system (image credit: Philae Team)
Legend to Figure 27: The figure shows the overall structure, the subsystems and the experiment compartment of the Lander. Some instruments are not visible in the drawing: specifically, the instruments in charge of analyzing the samples distributed by the SD2 (CIVA, COSAC, PTOLEMY), and the down-looking camera (ROLIS).
Figure 28: Side view schematics of the inner structure of the lander compartment showing the location of COSAC and PTOLEMY systems, the CONSERT antennas, the SESAME dust sensor and various CIVA cameras (image credit: Philae Team)
The general tasks of Philae are to get a first in situ analysis of primitive material from the early solar system and to study the structure of a cometary nucleus which reflects growth processes in the early solar system and to provide ground truth for Rosetta Orbiter instruments. The scientific objectives of the Lander are:
• determining the composition (elemental, isotopic, mineralogical and molecular) of the cometary surface material
• measuring the physical properties (thermal, electrical, mechanical) of the cometary surface material
• describing the large-scale structure (panoramic imaging, particles and magnetic field, and internal heterogeneity)
• monitoring the cometary activity (day/night cycle, changing distance to the Sun, outbursts).
Figure 29: Schematic view of the Philae landing scenario (image credit: Philae Team)
Legend of Figure 29: The ejection maneuver takes place at an altitude on the order of 1 km only; the Lander eject velocity partly cancels Rosetta’s orbital velocity, such that Philae moves on an comet-surface crossing ellipse, stabilized by a flywheel and the optional use of a cold-gas thrusters (in z direction). After touchdown on the moving comet surface, the cold-gas system is activated to provide a hold-down thrust until the harpoons have safely anchored the Lander.
Philae sensor complement:
The Rosetta Lander carries a further nine experiments, as well as a drilling system to take samples of subsurface material. The Lander instruments are designed to study in situ for the first time the composition and structure of the surface and subsurface material on the nucleus. The science payload of the lander consists of ten instruments with a mass of ~27 kg, making up nearly one-third of the mass of the lander. 67)
Table 15: The payload of the Rosetta lander Philae lead investigators: Jean-Pierre Bibring and Hermann Boehnhard
For the collection of samples and the deployment of instruments it is important to note that the Lander can be rotated around its z (vertical) axis by 360º defining a “working circle” around the Lander body axis. Thus, arbitrary locations can be accessed by the sampling drill (SD2), the down-looking camera (ROLIS), and the APXS sensor; the MUPUS-PEN and the SESAME-PP electrodes are attached to the latter two instruments. Also the stereo camera pair of CIVA will be able to image a full panoramic of 360º using the Lander rotation capability.
Note that the landing gear also provides a tilting capability. This capability had to be drastically reduced in range (to ±5º) after the change of target comet in 2003 to ensure a safe landing.
The science operations of Philae are divided into various phases. During the 10 year cruise, check-ups, calibrations, software and command up-loads are scheduled as well as occasional observation campaigns for CIVA-P (flybys and ROMAP (flybys, solar wind, comet tail crossings).
After arrival at the comet, global mapping by the Orbiter instruments and the selection of a landing site, the Separation–Descent–Landing phase begins. Immediately before release from the Orbiter, thermal preparation and battery charging are foreseen. Immediately after the eject, the Landing Gear is unfolded, thereby releasing the CONSERT antennas. Then, the ROMAP boom is deployed. A telemetry contact to the Orbiter will be established a few minutes after release until well after landing. During descent (30–60 min) to the comet’s surface, scientific measurements (images by ROLIS, magnetic field measurements by ROMAP-MAG, dust impact by SESAME-DIM and -CASSE, calibrations of SESAME-CASSE and MUPUS-TM) will be performed to monitor the cometary environment between the Orbiter and the surface of the nucleus, to observe the nucleus while approaching, to characterize remotely the landing site and to document the touchdown event of the Lander at the surface. ROLIS descent images will be taken until touchdown and MUPUS-ANC measurements during the actual anchoring.
During the “first science sequence” of approximately five days, Philae will be operated mainly on primary batteries, thus minimizing sensitivity to landing geometry (solar irradiance of the cells). In the first 60 hours following the touch-down, all instruments will work in their baseline mode at least once at full completion of their relevant science goals. In particular a full panorama of the landing site will be taken by CIVA-P immediately after landing and cometary samples will be acquired by SD2, both from the surface and from the maximum depth reachable with drill (i.e., about 0.2 m); these samples will then be processed by the relevant instruments (COSAC, Ptolemy, CIVA-M). MUPUS-PEN and APXS will be deployed and thermal conductivity, thermal diffusivity, strength measurements be made by MUPUS and the first X-ray and alpha spectra will be recorded by APXS. CONSERT will sound the nucleus over at least one full Orbiter orbit relative to the Lander. ROMAP will observe the daily variation of magnetic field and the plasma properties. All three parts of SESAME will perform measurements (PP only after MUPUS-PEN and/or APXS have been deployed). The Lander resources should enable at least a partial redo of this sequence over the following 60 hours, if partial failure (e.g., in data transmission) had happened. If performed successfully, the first sequence will secure a “minimum science success” of the Lander mission. 68)
During the “long-term science mission” (up to three months until r = 2 AU is reached) all instruments will be operated mostly sequentially, powered by the solar cells and buffered by the secondary (rechargeable) batteries. The Lander has enough flexibility to allow—by rotation around its body axis—the optimized orientation of the solar cells with respect to the local time, to drill several boreholes, and to measure physical properties all around the landing site.
The data volume to be uplinked to Earth is 235 Mbit during descent and the first five days, and 65 Mbit during each subsequent 60 hour period. However, depending on actual telemetry coverage and Orbiter requirements, a significantly larger data volume is expected.
With the current best estimate of the comet environment, about 52–65 hours of primary mission operations are feasible (incl. a 30% system margin). Primary power during the first science sequence is 15–20 W; the solar cells generate 10 W during the day at 3 AU.
The long-term operations then rely entirely on the solar generator; the end of life will be determined either by overheating (the thermal system is designed for a range of 2–3 AU) or by insufficient power if the solar cell degradation (mainly by dust deposition) becomes too severe.
Figure 30: Artist’s impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko (image credit: ESA, C. Carreau, ATG medialab) 69)
Mission status: (Note: Rosetta was launched on 2 March 2004 and completed science observations on 30 Sept. 2016)
• May 5, 2022: ESA and the Zooniverse have launched Rosetta Zoo, a citizen science project that invites volunteers to engage in a cosmic game of 'spot the difference'. By browsing through pictures collected by ESA's Rosetta mission, you can help scientists figure out how a comet's surface evolves as it swings around the Sun. 70)
Figure 31: Rosetta Zoo comparison image. The Rosetta archive contains a huge number of images that have only been partially explored. Lots of eyes are needed to sift through them – given the complexity of the imagery, the human eye is better at detecting small changes than automated algorithms are (image credit: ESA/Zooniverse)
- Rosetta Zoo presents pairs of images collected by Rosetta’s OSIRIS camera showing Comet 67P's surface as it approached and moved away from the Sun. Volunteers are invited to view images of roughly the same region side by side and identify a variety of changes, from large-scale dust transport to comet chunks that moved or even vanished. Sometimes this may require zooming in or out a few times, or rotating the images to spot changes on different scales, getting up close and personal with the iconic comet.
- Thanks to the visual inspection of many volunteers, the project will produce maps of changes and active areas on the comet's surface, with labels for each type of change. Scientists will then be able to associate the activity of the comet with modifications on its surface, developing new models to link the physics of comet activity to observed changes such as lifted boulders or collapsed cliffs.
- Anybody can use Rosetta Zoo online for free, without needing to sign up, install an app or programme, or have any previous scientific experience.
- Rosetta spent over two years orbiting Comet 67P/Churyumov-Gerasimenko between 2014 and 2016. The spacecraft studied the comet up close, collecting unprecedented data to unlock some of the most intriguing mysteries surrounding the formation and evolution of our Solar System. Partway through Rosetta's studies, the comet approached the Sun – a moment known as 'perihelion'. Following its closest approach of about 186 million km from our star, the comet then moved away again. This meant that its surface was illuminated in different ways during the course of Rosetta’s mission.
Figure 32: Approaching perihelion. This series of images of Comet 67P/Churyumov–Gerasimenko was captured by Rosetta’s OSIRIS narrow-angle camera on 12 August 2015, just a few hours before the comet reached the closest point to the Sun along its 6.5-year orbit, or perihelion. The image at left was taken at 14:07 GMT, the middle image at 17:35 GMT, and the final image at 23:31 GMT. The images were taken from a distance of about 330 km from the comet. The comet’s activity, at its peak intensity around perihelion and in the weeks that follow, is clearly visible in these spectacular images. In particular, a significant outburst can be seen in the image captured at 17:35 GMT (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/ID)
- Rosetta witnessed many landscape changes on Comet 67P: from the impressive fall of cliffs and the formation of pits, to evolving dust patterns and rolling boulders. Scientists are interested in using these changes to investigate the detailed mechanism through which a comet sheds its outer layers, as sunlight heats the ice and dust surrounding the nucleus.
- The sheer number of surface changes, however, makes charting them a highly complex task. So scientists are looking for your help.
Vast amounts of data need a vast number of eyes
- "The Rosetta archive, which is openly accessible to scientists and the public, contains a vast amount of data collected by this extraordinary mission that have only been partially explored," says Bruno Merín, head of ESA's ESAC Science Data Centre near Madrid, Spain.
- "In the past few years, astrophotographers and space enthusiasts have spontaneously identified changes and signs of activity in Rosetta's images. Except for a few cases, though, it has not been possible to link any of these events to surface changes, mostly due to the lack of human eyes sifting through the whole dataset. We definitely need more eyes!"
- This is why ESA partnered with the Zooniverse, the world's largest and most popular platform for people-powered research. The new Rosetta Zoo project presents a particular set of data: pairs of images collected by Rosetta's OSIRIS camera showing Comet 67P's surface before and after perihelion.
- Volunteers are invited to view images of roughly the same region side by side and identify a variety of changes, from large-scale dust transport to comet chunks that moved or even vanished. Sometimes this may require zooming in or out a few times, or rotating the images to spot changes on different scales, getting up close and personal with the iconic comet.
- "Given the complexity of the imagery, the human eye is much better at detecting small changes between images than automated algorithms are," explains Sandor Kruk, a postdoctoral researcher at the Max Planck Institute for Extraterrestrial Physics near Munich, Germany, who first conceived and initiated the project during his ESA research fellowship a couple of years ago.
- "The OSIRIS images have been publicly available in the archives for some time, but many images have not been analysed yet for changes in the surface of the comet. That is why we decided to set up this citizen science project and ask volunteers to inspect Rosetta images of 67P. Given the excitement Rosetta generated during its mission, we hope this project will be joined by many members of the public to help scientists analyse the data it generated."
Figure 33: Rosetta Zoo comparison image. Thanks to the visual inspection of many volunteers, the project will produce maps of changes and active areas on the comet's surface, with labels for each type of change. Scientists will then be able to associate the activity of the comet with modifications on its surface, developing new models to link the physics of comet activity to observed changes such as lifted boulders or collapsed cliffs (image credit: ESA/Zooniverse)
Your responses will improve our understanding of the Solar System
- Thanks to the visual inspection of many volunteers, the project will produce maps of changes and active areas on the comet's surface, with labels for each type of change. Scientists will then be able to associate the activity of the comet with modifications on its surface, developing new models to link the physics of comet activity to observed changes such as lifted boulders or collapsed cliffs.
- By digging through Rosetta's images and playing a cosmic game of 'spot the difference', you will help us reach new heights in our understanding of comets and the Solar System as a whole. But the benefits go both ways: we hope that by opening up this data to the public, we are improving the openness of our work, increasing citizen engagement in scientific research, and building stronger connections between science and society.
- Anybody can use Rosetta Zoo online for free, without needing to sign up, install an app or programme, or have any previous scientific experience. Spot the differences between as many or as few image pairs as you have time for – whether that’s five minutes whilst waiting for the bus, or regular evenings of cometary exploration.
- "What does a primitive comet look like? No one knows, but with the help of volunteers we can characterise how comets evolve now and understand the physics driving those changes: then we will be able to rewind the movie of cometary evolution all the way back to the origin of the Solar System," comments planetary scientist Jean-Baptiste Vincent from the DLR Institute of Planetary Research in Berlin, Germany.
• April 29, 2021: A precision magnetic valve originally designed to help steer a lander down to a comet has found a surprise terrestrial use through ESA’s Technology Transfer and Patent Office: adding flavors to beverages within a few thousandths of a second per each can or bottle. 71)
- Modern filling carousels for beverages are already miracles of automation, typically capable of filling hundreds of bottles, cans or cartons per minute. But these complex systems are optimized for single, large production batches. Meanwhile the market is moving on.
- “Visit any supermarket today and you’ll see a vast variety of different beverages on offer, from energy drinks to flavored waters,” explains Wolfgang Teichmann, managing director of KTW Technology.
Figure 34: Drinks dosing seen in slow motion. Based on its SmartValve Technology, KTW's High-Speed Precision Dosing system can provide incredibly accurate doses of between 0.1 and 3.0 ml, typically used to add flavor to a prefilled ‘base liquid’ such as water and specially designed to minimize wasteful splashes. The valve technology is in addition the base technology for several industrial solutions, made by KTW, to increase efficiency and reduce emissions, pesticides or waste (image credit: KTW Technology)
- “But traditional filling systems are not able to keep up in an efficient way with this widened product portfolio. Switching between filling different products requires prolonged downtime to get pipes dry and clean, because manufacturers do not want leftover flavors contaminating their next batch.
- “Instead, our aim has been to create a solution where fewer, faster dosing valves could be used to deliver the flavors as a concentrate at the end of the filling process, making systems more flexible and energy-efficient, and significantly reducing the time and resources lost during cleaning.”
- The target was to design a more efficient and sustainable solution. To make this possible, KTW has made use of space technology: a quick reacting precision valve that, unusually, has just one moving part – a ball that sits in a ‘valve seat’, keeping the valve closed until moved by a magnetic field to open it within a thousandth of a second, or millisecond.
- In fact the magnetic valve was originally designed for just this purpose by space engineer Dietmar Neuhaus of the German Aerospace Center, DLR. His aim was to achieve precision maneuverability of satellites using ‘cold gas thrusters’, where small amounts of gas are released to gain movement, like letting go of a balloon. The idea was initially proposed for the Rosetta spacecraft’s Philae lander, although in the end an alternative method was selected.
- “This valve design has a number of benefits over traditional designs, including those with springs,” explains Dietmar Neuhaus. “With only one moving part, it has a very long lifecycle. Its direct switching function means it is extremely quick to react to the incoming signal and very precise in the dose it delivers.”
- With the help of EurA, one of ESA’s technology brokers in Germany, KTW developed the idea to use and to develop further the valve technology . Its development was subsequently supported through an ESA Technology Transfer Demonstration project.
Figure 35: A precision magnetic valve originally designed to help steer a lander down to a comet has found a surprise terrestrial use through ESA’s Technology Transfer and Patent Office: adding flavors to beverages within a few thousandths of a second per each can or bottle (image credit: KTW Systems)
- Wolfgang Teichmann adds: “In a typical beverage dosing system, you would normally have a carousel with lots of valves – often over a hundred – to fill the containers with the final liquid, whereas with our solution you only need one to three valves providing microdoses of the concentrate at the end of the line. Speed and precision are vital; we can fill up to 120,000 cans per hour.
- “Longevity is also important in the filling industry. Valves typically have a short lifetime, whereas our valves, with just one moving part, have been shown to last for over 10 billion doses, and require less maintenance. And when any is needed, the fix is quick and simple, taking minutes instead of the weeks needed for a standard system repair. It simply just be a matter of exchanging the ball and valve seat.”
- KTW’s High-Speed Precision Dosing System can either be integrated within an existing production system or deployed on a stand-alone basis.
- “As a company, we’re motivated to boost efficiency, reduce waste and increase sustainability, following our slogan 'SpaceTech 4 Planet Earth',” notes Wolfgang Teichmann. “So for instance our Air Flow Saver system allows users to save up to 90% of their compressed air use: German industry spends 4.5 billion on using compressed air annually, which costs eight to 10 times more than conventional power sources.
- “Giving an idea how it works in practice, a customer might use compressed air to dry out a Tetrapak label before its filling date is added. Normally this compressed air is left blowing continuously, but our system only opens the valve to release air when a vision sensor shows a label is present, for just 30 milliseconds at a time. When passing five Tetrapaks per second the blow off station, it will save 85% of compressed air. And as we are pulsing in real-time, this blowing increase the drying effect.”
ESA's Technology Transfer and Patent Office
- The new technologies, systems and know-how making space missions possible often hold much wider potential in the terrestrial sphere. It is the task of ESA’s Technology Transfer and Patent Office to explore this potential by identifying and developing novel business opportunities for providers of space technologies and systems.
• October 28, 2020: After years of detective work, the second touchdown site of Rosetta’s Philae lander has been located on Comet 67P/Churyumov-Gerasimenko in a site that resembles the shape of a skull. Philae left its imprint in billions-of-years-old ice, revealing that the comet’s icy interior is softer than cappuccino froth. 72)
- Philae descended to the surface of the comet on 12 November 2014. It rebounded from its initial touchdown site at Agilkia and embarked on a two-hour flight, during which it collided with a cliff edge and tumbled towards a second touchdown location. Philae eventually came to a halt at Abydos, in a sheltered spot that was only identified in Rosetta imagery 22 months later, a few weeks before the conclusion of the Rosetta mission.
- ESA’s Laurence O’Rourke, who played the leading role in finding Philae in the first instance, was also determined to locate the previously undiscovered second touchdown site.
- “Philae had left us with one final mystery waiting to be solved,” says Laurence. “It was important to find the touchdown site because sensors on Philae indicated that it had dug into the surface, most likely exposing the primitive ice hidden underneath, which would give us invaluable access to billions-of-years-old ice.”
- Together with a team of mission scientists and engineers, he set about pulling together data from both Rosetta and Philae instruments to find and confirm the ‘missing’ touchdown site.
Figure 36: Philae creates eye of the skull. The comet topography at Philae’s second touchdown site resembles the shape of a skull with a pointed ‘hat’ when viewed from above. This gif shows the feature that resembles a skull face, with Philae superimposed for scale (Philae’s ‘body’ measures about 1 m across, and each leg is 1.5 m long). Philae’s body compressed into the ice-dust scenery to create the skull’s right eye. The dark region just above the skull’s right eye is the entrance to a gap between the two boulders nicknamed ‘skull-top crevice’, where Philae acted like a windmill to pass between them.
Figure 37: How Philae left its mark during touchdown two. This graphic presents the data collected by Philae’s ROMAP instrument – a magnetometer boom – during the time of the second touchdown on Comet 67P/Churyumov-Gerasimenko on 12 November 2014, matched with imagery showing evidence of the key moments of Philae’s interaction with the surface. Signatures were created in the magnetic data of the ROMAP boom relative to the lander body when the boom physically moved as it struck a surface (the boom sticks out 48 cm from the lander body). This created a characteristic set of spikes in the magnetic data, which provided an estimate of the duration of Philae stamping into the ice. The data could also be used to constrain the acceleration of Philae during these contacts. The data shows that Philae spent nearly two full minutes at touchdown site two, making contact with the surface multiple times. - The data plot is labelled with five different events, corresponding to the imagery. Initially travelling in a downward direction, Philae slides down the edge of a boulder (1) and flips vertically, rotating like a windmill to pass between two boulders (2) exposing layers of ice in the crevice walls with its feet. A dust wall was created by the windmill action, pushing through the dust that had heaped up between the boulders up to that point in time. The crevice is about 2.5 m long and is curved with a width of 1-1.5 m, allowing Philae to pass through. Philae then stamps a 25 cm imprint of the top of the lander into the comet’s surface (3) – a hole made by the top of the SD2 (Sampling, Drilling and Distribution device) tower that sticks up above the top of Philae can be recognized. Philae then climbed out of the crevice, being pushed down once more by an overhang (4a), knocking off material in the process, with its top surface then creating an impression in the dust corresponding to the ‘eye’ of the feature that resembles a skull face (4b). The ROMAP data also reveal information about the speed and direction of travel. When Philae first entered the region it was travelling downwards at 20 cm/s and forwards at 10 cm/s. When it left the area it was travelling upwards at less than 1 cm/s and forwards at 9 cm/s. It never flew higher than one meter above the surface in its final flight to touchdown point three, 30 m away (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Data: ESA/Rosetta/Philae/ROMAP; Analysis: O’Rourke et al (2020)
The star of the show
- Although a bright patch of ‘sliced ice’ observed in high-resolution images from Rosetta’s OSIRIS camera proved crucial in confirming the location, it was Philae’s magnetometer boom, ROMAP, that turned out to be the star of the show. The instrument was designed to make magnetic field measurements in the comet’s local environment, but for the new analysis the team looked at changes recorded in the data that arose when the boom – which sticks out 48 cm from the lander – physically moved as it struck a surface. This created a characteristic set of spikes in the magnetic data as the boom moved relative to the lander body, which provided an estimate of the duration of Philae stamping into the ice. The data could also be used to constrain the acceleration of Philae during these contacts.
Figure 38: Animation showing how Rosetta’s Philae lander moved through touchdown site two on Comet 67P/Churyumov-Gerasimenko on 12 November 2014. Initially travelling in a downward direction, Philae slides down the edge of a boulder (1) and flips vertically, rotating like a windmill to pass between two boulders (2) exposing layers of ice in the crevice walls with its feet. A dust wall was created by the windmill action, pushing through the dust that had heaped up between the boulders up to that point in time. The crevice is about 2.5 m long and is curved with a width of 1–1.5 m, allowing Philae to pass through. Philae then stamps a 25 cm imprint of the top of the lander into the comet’s surface (3) – a hole made by the top of the SD2 (Sampling, Drilling and Distribution device) tower that sticks up above the top of Philae can be recognized. Philae then climbed out of the crevice, knocking off material from an overhang (4a) and was pushed down again with its top surface, creating an impression in the dust corresponding to the ‘eye’ of the feature that resembles a skull face (4b). The colors correspond to the data presented in the accompanying annotated infographic [video credit: Image: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Data: ESA/Rosetta/Philae/ROMAP; Analysis: O’Rourke et al (2020)]
- ROMAP's data were cross-correlated with those collected by Rosetta's RPC magnetometer at the same time to determine Philae's attitude and exclude any influence from the background magnetic field of the plasma environment around the comet.
- "We weren't able to make all the measurements we planned in 2014 with Philae, so it is really amazing to use the magnetometer like this, and to combine data from both Rosetta and Philae in a way that was never intended, to give us these wonderful results," says Philip Heinisch, who led the analysis of the ROMAP data.
- A reanalysis of the touchdown data found that Philae had spent nearly two full minutes at the second touchdown site, making at least four distinct surface contacts as it ploughed across it. One particularly notable imprint revealed in the images was created as Philae's top surface sank 25 cm into the ice on the side of a crevice, leaving identifiable marks of its drill tower and sides. The spikes in the magnetic field data arising from the boom movement showed that it took Philae three seconds to make this particular depression.
Figure 39: Where is 'skull face'? Rosetta's Philae lander touched down on Comet 67P/Churyumov-Gerasimenko on 12 November 2014 and made multiple contacts with the surface before arriving at its final resting place. Its second touchdown site was recently identified just 30 meters away from its final position, in a location that resembles the shape of a skull with a pointed ‘hat' when viewed from above. This animation shows the location of ‘skull face' hidden in the shadowed cliffs of the comet: when the exposure of the image is enhanced, the touchdown site is revealed. The animation points out the various features of the ‘skull'. For example, Philae's body compressed into the ice-dust scenery to create the skull's right eye [video credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Analysis: O'Rourke et al (2020)]
- "The shape of the boulders impacted by Philae reminded me of a skull when viewed from above, so I decided to nickname the region ‘skull-top ridge' and to continue that theme for other features observed," says Laurence.
- "The right ‘eye' of the ‘skull face' was made by Philae's top surface compressing the dust while the gap between the boulders is ‘skull-top crevice', where Philae acted like a windmill to pass between them."
- Analysis of images and data from OSIRIS and Rosetta's spectrometer VIRTIS confirmed that the bright exposure was water-ice covering an area of about 3.5 m2. Although the ice was mostly in shadow at the time of the landing, the Sun was directly illuminating the area when the images were taken months later, lighting it up like a beacon to stand out against everything around it. The ice was brighter than the surrounds because it had not been previously exposed to the space environment and undergone space weathering.
Figure 40: A light shining in the darkness. Rosetta's Philae lander touched down on Comet 67P/Churyumov-Gerasimenko on 12 November 2014 and made multiple contacts with the surface before arriving at its final resting place. This animated gif focuses on the second touchdown site, which is characterized by a bright patch of exposed water-ice covering an area of about 3.5 m2. Although the ice was mostly in shadow at the time of the landing, the Sun was directly illuminating the area when these images were taken 22 months later, lighting it up like a beacon to stand out against everything around it. In this animated gif, every second image has its brightness/contrast fully reduced to show how the ice in the crevice is brighter than all of the surrounding regions [image credit: ESA/Rosetta/Philae/ROLIS/DLR; all other images: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Analysis: O'Rourke et al (2020)]
- "It was a light shining in the darkness," says Laurence, noting that it was located just 30 m away from where Philae was finally imaged on the comet surface.
- While an exciting conclusion in the search for the second touchdown site, the study also provides the first in situ measurement of the softness of the icy-dust interior of a boulder on a comet.
- "The simple action of Philae stamping into the side of the crevice allowed us to work out that this ancient, billions-of-years-old, icy-dust mixture is extraordinarily soft – fluffier than froth on a cappuccino, or the foam found in a bubble bath or on top of waves at the seashore," adds Laurence.
- The study also allowed an estimate of the boulder's porosity – how much empty space exists between the ice-dust grains inside the boulder – of about 75%, which is in line with the value measured previously for the whole comet in a separate study. The same study showed that the comet is homogeneous anywhere in its interior on all size scales down to about one meter. This implies that the boulders represent the overall state of the comet's interior when it formed some 4.5 billion years ago.
- "This is a fantastic multi-instrument result that not only fills in the gaps in the story of Philae's bouncy journey, but also informs us about the nature of the comet," says Matt Taylor, ESA's Rosetta project scientist. "In particular, understanding the strength of a comet is critical for future lander missions. That the comet has such a fluffy interior is really valuable information in terms of how to design the landing mechanisms, and also for the mechanical processes that might be needed to retrieve samples."
Figure 41: Flight over Abydos valley. Rosetta's Philae lander touched down on Comet 67P/Churyumov-Gerasimenko on 12 November 2014 and made multiple contacts with the surface before arriving at its final resting place in a location named Abydos. This video presents a flyover of the Abydos valley including Philae's second touchdown location in a region nicknamed ‘Skull-top ridge', as viewed on a high-resolution Digital Terrain Model reconstructed from OSIRIS imagery. The Abydos valley is a boulder-strewn location with the touchdown area located on the edge of a hill-like feature that towers 30 m above the valley at its maximum point. - The flyover begins with the skull-top boulders circled, before the viewer flies towards them, and make a 360º flight around. Although the fine details of Philae's interaction with touchdown site two are not shown in this shape model, the ice contained inside the crevice itself is clearly visible. - For orientation, at 45 s, skull-top ‘hat' is to the left of the crevice, and ‘skull face' is to the right. Skull-top hat has a length of 5 m and a maximum height of 4 m. The skull face boulder is over 6 m in length. Both boulders are about 2.5 m wide. Although the boulders have a distinct shape from the initial fly in perspective, the challenge in finding them from other viewing points becomes clear when seen from other perspectives [video credit: Video prepared by and music composed by Gerhard Paar (Joanneum Research Forschungsgesellschaft mbH); Analysis: O'Rourke et al (2020)]
• September 21, 2020: ESA's Rosetta mission has revealed a unique kind of aurora, an exciting phenomenon seen throughout the Solar System, at its target comet, Comet 67P/Churyumov-Gerasimenko. 73)
Figure 42: ESA's Rosetta mission has revealed a unique kind of aurora, an exciting phenomenon seen throughout the Solar System, at its target comet, Comet 67P/Churyumov-Gerasimenko. This image shows the key stages of the mechanism by which this aurora is produced: as electrons stream out into space from the Sun and approach the comet, they are accelerated and go on to break down molecules in the comet's environment. This destructive process can throw out excited atoms, which then ‘de-excite' to produce the observed aurora. To reveal the auroral nature of the emissions, the study relies on a set of in situ and remote-sensing instruments aboard Rosetta (RPC, Rosina, Virtis, Miro and Alice), as shown to the right of the infographic in the spacecraft schematic [image credit: ESA (spacecraft: ESA/ATG medialab)]
- At Earth, auroras form as charged particles from the Sun interact with our planet's magnetic field to create shimmering displays of color and light in the high-latitude sky. While these light displays have been seen at various planets and moons in the Solar System, and around a more distant star, observations from ESA's comet-chasing Rosetta mission now reveal unique auroral emissions at the spacecraft's target comet: 67P/Churyumov-Gerasimenko (67P/C-G).
- These emissions are created as charged particles stream towards the comet from the Sun – a flow known as the solar wind – and interact with the gas surrounding the comet's icy, dusty nucleus.
- "The glow surrounding 67P/C-G is one of a kind," says Marina Galand of Imperial College London, UK, lead author of the new study. 74) "By digging into data from numerous instruments on Rosetta and linking them together, we've discovered that this glow is auroral in nature: it's caused by a mix of processes, some seen at Jupiter's moons Ganymede and Europa and others at Earth and Mars."
- These processes define how the envelope of gas (or coma) around 67P/C-G becomes excited – that is, made to glow – and how the particles causing this excitation are given a boost of energy and sped up. 67P/C-G's aurora shows up in ultraviolet light, as seen in martian auroras detected by ESA's Mars Express (although the ‘colors' of the auroras at 67P/C-G and Mars differ).
- To reveal more than what one instrument can offer, Marina and colleagues connected various measurements made by Rosetta, both in situ and remote-sensing, using a physics-based model.
- "By doing this, we didn't have to rely upon just a single dataset from one instrument," says Marina. "Instead, we could draw together a large, multi-instrument dataset to get a better picture of what was going on. This enabled us to unambiguously identify how 67P/C-G's ultraviolet atomic emissions form, and to reveal their auroral nature."
Figure 43: Animation of ultraviolet aurora being produced at Rosetta's comet (video credit: ESA)
- The ultraviolet emissions Rosetta observed at comet 67P/C-G have shown up before, and were thought to be ‘dayglow', a process caused by solar light particles (photons) interacting with cometary gas.
- However, this study shows that these emissions are aurora instead: they are driven not by photons, but by electrons in the solar wind that have been accelerated in the comet's nearby environment. "These electrons then interact with molecules in the coma to produce the auroral glow. The process by which the electrons are accelerated is similar to some of the processes that drive auroras at Earth and Mars, despite 67P/C-G lacking an intrinsic magnetic field," adds Marina. "In fact, the magnetic environments of moons, planets, and comets are all very different, so it's exciting and intriguing that we see auroras at all of them."
- Exploring the emission at 67P/C-G will enable scientists to assess how the particles comprising the solar wind change over time, something that is crucial for understanding space weather throughout the Solar System. It also confirms that ultraviolet auroras can occur at comets, and brings insight into how these exciting, and often spectacular, light shows form at different Solar System objects.
- Following its rendezvous with 67P/C-G in 2014, Rosetta has provided a wealth of data that has underpinned our exploration of how the Sun and solar wind interact with comets. The spacecraft was the first to orbit a comet's nucleus, the first to fly alongside a comet as it travelled into the inner Solar System, the first to dispatch a robotic lander to a cometary nucleus, and the first to image a cometary surface at such a high spatial resolution.
- "And now, it's the first to spot an ultraviolet aurora at a comet! Auroras are inherently exciting – and this excitement is even greater when we see one somewhere new, or with new characteristics," adds ESA's Rosetta project scientists Matt Taylor.
- "This multi-instrument analysis brings together more pieces of the puzzle in our understanding of both auroras throughout the Solar System, and of the various phenomena we see around comets.
- "It uses data from numerous instruments aboard Rosetta, and is a great example of why we fly several different instruments, with different goals and techniques and areas of focus, on any given mission: to get a full picture of the objects and processes going on in our cosmic environment."
• September 07, 2020: A permeable heart with a hardened facade –the resting place of Rosetta's lander on comet 67P/Churyumov-Gerasimenko is revealing more about the interior of the 'rubber duck' shaped-body looping around the Sun. 75)
Figure 44: The graphic shows the signal connecting the CONSERT instrument on Philae, on the surface of the comet, to the one on the Rosetta orbiter. The fan like appearance is a result of the motion of Rosetta along its orbit, with the colors marking the separate signal paths as the orbit evolves. The image at the bottom shows the signals in more detail, propagating inside the comet from Philae to the points from where they leave the comet to the orbiter. The curving is a result of the projection of its paths on the bumpy surface of the comet. The bluer color indicates more shallow paths (just a few centimeters), while the redder tones show where the signals penetrated below 100 m in depth. (image credit: ESA/Rosetta/Philae/CONSERT)
- A recent study suggests that the comet's interior is more porous than the material near the surface. The results confirm that solar radiation has significantly modified the comet's surface as it travels through space between the orbits of Jupiter and Earth. Heat from the Sun triggers an ejection and subsequent falling back of material. 76)
- Location, location, location. That was key for the radar instrument on the Rosetta spacecraft and its Philae lander, which was designed to probe the comet's nucleus. The CONSERT experiment involved two antennas sending precise signals to each other. But when Philae went missing upon landing on November 2014, scientists had to work with estimated values.
- Philae operated for over two days on the surface – 63 hours, to be precise.
- "We managed to define the region where the lander was with a margin of about 150 m. The real landing site was in this region," explains Wlodek Kofman, emeritus principal investigator of CONSERT.
- It took nearly two years to find out where Philae was. In September 2016 the exact position of Philae was retrieved within the area identified by CONSERT.
- Precise 3D models of the comet with Philae in the picture "allowed us to revisit the measurements and improve our analysis of the interior," says Wlodek.
- The time for the signal to travel between the two radars offers insights into the comet's nucleus, such as porosity and composition. The team discovered that rays propagated at different velocities, indicating varying densities within the comet.
- The discussion is still open, but Wlodek believes that "this strongly suggests that the less dense interior has kept its pristine nature." Known as the most primitive objects in our cosmic neighborhood, comets might hold, deep inside, valuable clues about the formation of our Solar System.
• March 13, 2020: Scientists have detected ammonium salts on the surface of Comet 67P/Churyumov-Gerasimenko (Figure 45) by analyzing data collected by the Visible, Infrared and Thermal Imaging Spectrometer (VIRTIS) on ESA's Rosetta mission between August 2014 and May 2015. 77)
Figure 45: As VIRTIS mapped the comet during the first half of Rosetta's mission, the data revealed how its surface is as dark as coal, and slightly reddened by a mixture of carbon-based compounds and opaque minerals. The instrument also spotted local patches of water and carbon dioxide ice, along with a puzzling but almost ubiquitous absorption feature around the infrared wavelength of 3.2 µm. The nature of the compound that could cause such a feature, however, remained unclear until now [image credit: O. Poch, IPAG, UGA/CNES/CNRS (left); ESA/Rosetta/NavCam – CC BY-SA IGO 3.0 (right)]
- The new study, led by Olivier Poch of Institut de Planétologie et d'Astrophysique de Grenoble, France, and published in the journal Science, adds to the complementary measurements obtained in the comet's atmosphere, or coma, using another instrument, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), which were published in Nature Astronomy earlier this year.
- As VIRTIS mapped the comet during the first half of Rosetta's mission, the data revealed how its surface is as dark as coal, and slightly reddened by a mixture of carbon-based compounds and opaque minerals. The instrument also spotted local patches of water and carbon dioxide ice, along with a puzzling but almost ubiquitous absorption feature around the infrared wavelength of 3.2 µm. The nature of the compound that could cause such a feature, however, remained unclear until now.
- To solve the enigma, a team of scientists have been creating ‘artificial' cometary surfaces in the laboratory (an example is shown in this image on the left), testing their properties and comparing them to the VIRTIS observations. With this aim, the scientists have produced fine particles of water ice containing dark dust grains and a variety of compounds. Then, they exposed these particles to cometary-like conditions – vacuum and low temperature. After several hours, all the ice had sublimated, leaving a surface made of porous dust, analogous to a cometary surface.
- The result of such experiments indicate that the mysterious absorption feature observed by VIRTIS at Comet 67P is predominantly due to salts of ammonium (NH4+), which are mixed with dark dust and detected on all kinds of terrains across the comet.
- The presence of these salts might considerably increase the amount of nitrogen that scientists had previously expected to find on this comet, and possibly on other comets as well. The findings agree with the recent detection, by the ROSINA instrument on Rosetta, of gases produced by the sublimation of ammonium salts on dust grains ejected from the comet.
- A similar absorption feature has also been observed on several asteroids, both in the main belt and in Jupiter's Trojan family, as well as on Jupiter's moon Himalia, suggesting that these bodies contain ammonium salts, too. The presence of these salts might hint at a link in the chemical composition between asteroids, comets and possibly the proto-solar nebula, providing a tantalizing scenario for the delivery of nitrogen – a key element for the chemistry of life as we know it on Earth – to the inner planets of the Solar System.
• January 20, 2020: Observations from ESA's Rosetta spacecraft are shedding light on the mysterious make-up of Comet 67P/Churyumov-Gerasimenko, revealing a mix of compounds thought to be essential precursors to life – including salts of ammonium and a particular type of hydrocarbons. 78)
- These new studies suggest the comet gleaned this material from the presolar cloud where the Solar System formed 4.6 billion years ago.
- Comets have a nucleus consisting of ice and dust, from which material sublimates when warmed by sunlight to form a gaseous enveloping ‘coma'. These comas contain a mix of molecules that largely match theoretical predictions, with one outstanding exception: nitrogen gas, which is usually present in far smaller amounts than expected.
- "The reason behind this nitrogen depletion has remained a major open question in cometary science," says Kathrin Altwegg of the University of Bern, Switzerland, principal investigator for the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument and lead author of a new study. 79)
- "Using ROSINA observations of Comet 67P, we discovered that this ‘missing' nitrogen may in fact be tied up in ammonium salts that are difficult to detect in space."
- Ammonia, a molecule comprising one nitrogen and three hydrogen atoms, is one of the main carriers of volatile nitrogen, and readily combines with various acids found in both the space between stars and in cometary ice to form salts. These ammonium salts are thought to be the starting point for far more complex compounds – such as urea and glycine, the latter of which was also found on Rosetta's comet – that are known to be precursors to life as we know it on Earth.
- "Finding ammonium salts on the comet is hugely exciting from an astrobiology perspective," adds Kathrin. "This discovery highlights just how much we can learn from these intriguing celestial objects."
- Kathrin and colleagues used ROSINA data gathered during the final phase of the mission, from when Rosetta was performing close flyovers of the comet in September 2016. These data were somewhat serendipitous: Rosetta ventured closer to 67P than ever before, reaching just 1.9 km above the comet's surface, and became completely enshrouded by dust.
- "Because of the dusty environment at the comet, and the rotation of Earth, we were not able to readily communicate with Rosetta via our antennas at the time and had to wait until the next morning to reestablish our communication link," says Kathrin.
- "None of us slept well that night! But both Rosetta and ROSINA ended up behaving perfectly, flawlessly measuring the most abundant and most diverse mass spectra yet, and revealing many compounds we had never spotted on 67P before."
- Adding to this investigation of 67P, another recent study made use of a different instrument on Rosetta, the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), which operated until May 2015, to explore the properties of the comet's nucleus.
- The researchers explored several million infrared spectra gathered with VIRTIS and discovered clear signs of hydrogen and carbon chains known as organic aliphatic compounds – the first time such compounds have been spotted on the surface of a cometary nucleus.
- "Where – and when – these aliphatic compounds came from is hugely important, as they are thought to be essential building blocks of life as we know it," explains lead author Andrea Raponi of INAF, the National Institute for Astrophysics in Italy.
- "The origin of material such as this found in comets is crucial to our understanding of not only our Solar System, but planetary systems throughout the Universe."
- Comets are flung inwards towards the Sun from the outer reaches of the Solar System, and may deliver material to the inner planets as they travel. This material is thought to have either come from the young, still-forming Sun, or from the interstellar medium.
- "We found that the nucleus of Comet 67P has a composition similar to the interstellar medium, indicating that the comet contains unaltered presolar material," says co-author Fabrizio Capaccioni, also of INAF and principal investigator for VIRTIS.
- "This composition is also shared by asteroids and some meteorites that we have found on Earth, suggesting that these ancient, rocky bodies locked up various compounds from the primordial cloud that went on to form the Solar System."
Figure 46: This image shows salts of ammonium chloride (NH4Cl), image credit: University of Bern
- "This may mean that at least a fraction of the organic compounds in the early Solar System came directly from the wider interstellar medium – and thus that other planetary systems may also have access to these compounds," adds Raponi.
- Rosetta explored Comet 67P for over two years, ending its mission by crash-landing on the comet on 30 September 2016.
- "Although Rosetta operations ended over three years ago, it is still offering us an incredible amount of new science and remains a truly ground-breaking mission," adds Matt Taylor, ESA's Rosetta Project Scientist.
- "These studies tackled a couple of open questions in cometary science: why comets are depleted in nitrogen, and where comets got their material from. Inspiring discoveries such as these help us to understand a great deal more about not only comets themselves, but the history, characteristics and evolution of our entire cosmic neighborhood."
• January 15,2020: Astronomers using the combined powers of ESA's Rosetta mission and the ground-based Atacama Large Millimeter/submillimeter Array (ALMA) have traced the journey of phosphorus – one of life's building blocks – from star-forming regions to comets. 80)
- An essential element for life as we know it, phosphorus is present in our DNA and cell membranes. But how it arrived on the early Earth is something of a mystery.
- A new study combining data collected by the Rosetta mission at Comet 67P/Churyumov–Gerasimenko with ALMA observations of the star-forming region AFGL 5142 has revealed, for the first time, where molecules containing phosphorus form in the Universe. The research also shows how this element is carried in comets and how a particular molecule – phosphorus monoxide – may have played a crucial role in starting life on our planet. 81)
- "Life appeared on Earth about four billion years ago, but we still do not know the processes that made it possible," says Víctor Rivilla of INAF – Arcetri Astrophysical Observatory in Florence, Italy, who lead the new study.
- New stars and planetary systems arise in cloud-like regions of gas and dust in between stars, making these interstellar clouds the ideal places to start the search for life's building blocks.
- By observing such a stellar nursery with ALMA, Víctor and collaborators could pinpoint the formation sites of phosphorus-bearing molecules, which appear to be created while massive stars are formed. As flows of gas from young massive stars open up cavities in the surrounding cloud material, molecules containing phosphorus form on the cavity walls through the combined action of shocks and radiation from the infant star.
- The astronomers have also shown that phosphorus monoxide, which combines phosphorus with one oxygen atom, is the most abundant phosphorus-bearing molecule in the cavity walls of this particular star-forming region.
- Following the cosmic trail of this life-enabling compound, the team took their investigations closer to home, looking at comets in the Solar System.
- If the cavity walls of an interstellar cloud collapses to form a star, especially low-mass ones like our Sun, phosphorus monoxide can freeze out and get trapped in the icy dust grains that remain around the new star. Even before the star is fully formed, those dust grains come together to form pebbles, rocks and ultimately comets, which become transporters of phosphorus monoxide.
- The ROSINA instrument on Rosetta, which collected data at Comet 67P/C-G for over two years, had already found hints of phosphorus at the comet in 2016, but it was not clear what molecule had carried it there. After the ALMA observations suggested that phosphorus monoxide would be a very likely candidate, ROSINA scientists went back to their data and eventually found evidence of this molecule at Rosetta's comet.
- "Phosphorus is essential for life as we know it," says co-author and ROSINA Principal Investigator Kathrin Altwegg from University of Bern, Switzerland.
- "As comets most probably delivered large amounts of organic compounds to the Earth, the phosphorus monoxide found in Comet 67P/C-G may strengthen the link between comets and life on Earth."
- This first sighting of phosphorus monoxide at a comet helps astronomers draw a connection between star-forming regions, where the molecule is created, all the way to our planet.
Figure 47: This ALMA image shows a detailed view of the star-forming region AFGL 5142. A bright, massive star in its infancy is visible at the center of the image. The flows of gas from this star have opened up a cavity in the region, and it is in the walls of this cavity (shown in color), that phosphorus-bearing molecules like phosphorus monoxide are formed. The different colors represent material moving at different speeds. A joint study linking the presence of phosphorus monoxide in this star-forming region with analogous observations performed by the Rosetta mission at Comet 67P/Churyumov–Gerasimenko showed how this compound may have played a crucial role in starting life on our planet (image credit: ALMA (ESO/NAOJ/NRAO), Rivilla et al.)
Figure 48: This wide-field view shows the region of the sky, in the constellation of Auriga, where the star-forming region AFGL 5142 is located. This view was created from images forming part of the Digitized Sky Survey 2 (image credit: ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin)
- This first sighting of phosphorus monoxide at a comet helps astronomers draw a connection between star-forming regions, where the molecule is created, all the way to our planet.
- "The combination of the ALMA and ROSINA data has revealed a sort of chemical thread during the whole process of star formation, in which phosphorus monoxide plays the dominant role," explains Víctor.
- "The detection of phosphorus monoxide was clearly thanks to an interdisciplinary exchange between telescopes on Earth and instruments in space," adds Altwegg.
Figure 49: Our Solar System condensed from a cloud of gas and dust over 4.6 billion years ago. As the newborn planets settled in their orbits, gravitational perturbations are thought to have disrupted swarms of comets into the inner Solar System, impacting the rocky planets. As well as inheriting ingredients during the planet-forming process itself, comets are also believed to have delivered some of the basic ingredients for life to Earth, leading to life as we know it today (image credit: ESA) 82)
- This and similar results are a testament to the synergy between pioneering space science missions, such as the fleet operated by ESA, and cutting-edge ground-based astronomical facilities like the ones run in Chile by the European Southern Observatory (ESO), ALMA's European executive partner.
- "This study takes one of Rosetta's major results regarding prebiotic compounds – the detection of phosphorus, in this case – and digs further into the data," says Matt Taylor, ESA Rosetta project scientist.
- "It is an inspiring demonstration of the broader impact and importance of the cometary observations made by Rosetta to the broader astronomy community, deepening our understanding of how stars and planetary systems form and evolve."
• November 12, 2019: On 12 November 2014 Philae became the first spacecraft to land on a comet as part of the successful Rosetta mission to study Comet 67P/Churyumov-Gerasimenko. Five years later, and after the mission's official end in 2016, Rosetta is continuing to provide insights into the origins of our Solar System. 83)
- Rosetta's instruments have already discovered that the comet contained oxygen, organic molecules, noble gases and 'heavy' or deuterated water different to that found on Earth. - As scientists continue to analyze data from Rosetta's instruments, including the ionized gas or plasma, the results are improving our understanding of comets. Mission data is also being delivered to an archive as a future resource.
- Rosetta orbits the Sun every 6.5 years and will pass the Earth again, visible from ground-based telescopes, in 2021. ESA's future Comet Interceptor mission will build on Rosetta's success when it performs a flyby of a comet. But, unlike Rosetta, the comet will be new to our Solar System.
Figure 50: This video contains interviews with Charlotte Goetz, Research Fellow, ESA; Kathrin Altwegg, ROSINA instrument principal investigator, Rosetta/University of Bern; Colin Snodgrass, Comet Interceptor principal investigator (video credit: ESA)
• September 30, 2019: Friday 30 September 2016 was a bitter-sweet day for space exploration: the incredible Rosetta spacecraft reached the end of its hugely successful mission, fittingly, by touching down on the surface of the comet it had been studying from orbit for the previous two years. 84)
Figure 51: This image was captured by the spacecraft's wide-angle OSIRIS camera during the final hour of the mission from an altitude of about 400 m above the surface of Comet 67P/Churyumov-Gerasimenko. Its final resting place is not far from the top center of the image; see also this breathtaking sequence of images covering the final hours of the mission (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA – CC BY-SA 4.0)
- Rosetta arrived at the comet on 6 August 2014 after a ten year journey through space, and deployed lander Philae to its surface on 12 November 2014. Rosetta continued to study the icy, dusty object from near and far as the comet reached its closest approach to the Sun in August 2015 and moved towards the outer Solar System again.
- Conducting science until the very end, the descent gave Rosetta the opportunity to collect unique data on the comet's gas, dust and plasma environment very close to its surface, as well as take very high-resolution images and temperature measurements.
- While the mission operations have concluded, the science certainly continues. Intense activities also surround the preservation of Rosetta's highest resolution and best calibrated data in ESA's Planetary Science Archive, securing the mission's legacy for future generations.
- Last week marked another milestone as the final Science Working Team meeting was held at ESA's technical facility in the Netherlands. It was the 52nd of such meetings, the first having been held in the late 1990s. The meeting closed out the formal aspect of the mission and archiving activities and enabled teams to reflect on their efforts over the last decades. In addition, several days were dedicated to the latest and ongoing science activities, which are delving deep into the cross-instrument analysis of the comet. A number of the topics discussed are also presented in a recently published special edition of Astronomy and Astrophysics.
• September 18, 2019: Scientists analyzing the treasure trove of images taken by ESA's Rosetta mission have turned up more evidence for curious bouncing boulders and dramatic cliff collapses. 85)
- Rosetta operated at Comet 67P/Churyumov-Gerasimenko between August 2014 and September 2016, collecting data on the comet's dust, gas and plasma environment, its surface characteristics and its interior structure.
- As part of the analysis of some 76,000 high-resolution images captured with its OSIRIS camera, scientists have been looking for surface changes. In particular, they are interested in comparing the period of the comet's closest approach to the Sun – known as perihelion – with that after this most active phase, to better understand the processes that drive surface evolution.
Figure 52: Bouncing boulder on Comet 67P/C-G. An example of a boulder having moved across the surface of Comet 67P/Churyumov-Gerasimenko's surface, captured in Rosetta's OSIRIS imagery. The image was taken with the narrow-angle camera and shows the boulder in the lower third of the image [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA (CC BY-SA 4.0)]
Figure 53: An example of a boulder having moved across the surface of Comet 67P/Churyumov-Gerasimenko's surface, captured in Rosetta's OSIRIS imagery [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA (CC BY-SA 4.0); Analysis: J-B. Vincent et al (2019)]
Evolution of a bouncing boulder: The first image (left) provides a reference view of the comet, along with a close-up of the region under study. The smaller insets on the right show before and after images of the region containing the bouncing boulder, captured on 17 March 2015 and 19 June 2016, respectively. Impressions of the boulder have been left in the soft regolith covering the comet's surface as it bounced to a halt. It is thought to have fallen from the nearby cliff, which is about 50 m high. The graphic at the bottom illustrates the path of the boulder as it bounced across the surface, with preliminary measurements of the ‘craters' calculated.
- Loose debris is seen all over the comet, but sometimes boulders have been caught in the act of being ejected into space, or rolling across the surface. A new example of a bouncing boulder was recently identified in the smooth neck region that connects the comet's two lobes, an area that underwent a lot of noticeable large-scale surface changes over the course of the mission. There, a boulder about 10 m-wide has apparently fallen from the nearby cliff, and bounced several times across the surface without breaking, leaving ‘footprints' in the loosely consolidated surface material.
- "We think it fell from the nearby 50 m-high cliff, and is the largest fragment in this landslide, with a mass of about 230 tons," said Jean-Baptiste Vincent of the DLR Institute for Planetary Research, who presented the results at the EPSC-DPS conference in Geneva today.
- "So much happened on this comet between May and December 2015 when it was most active, but unfortunately because of this activity we had to keep Rosetta at a safe distance. As such we don't have a close enough view to see illuminated surfaces with enough resolution to exactly pinpoint the ‘before' location of the boulder."
- Studying boulder movements like these in different parts of the comet helps determine the mechanical properties of both the falling material, and the surface terrain on which it lands. The comet's material is in general very weak compared with the ice and rocks we are familiar with on Earth: boulders on Comet 67P/C-G are around one hundred times weaker than freshly packed snow.
- Another type of change has also been witnessed in several locations around the comet: the collapse of cliff faces along lines of weakness, such as the dramatic capture of the fall of a 70 m-wide segment of the Aswan cliff observed in July 2015. But Ramy El-Maarry and Graham Driver of Birkbeck, University of London, may have found an even larger collapse event, linked to a bright outburst seen on 12 September 2015 along the northern-southern hemisphere divide.
Figure 54: An outburst event on Comet 67P/Churyumov-Gerasimenko took place on 12 September 2015 and is thought to be associated with one of the most dramatic cliff collapses captured during the lifetime of the Rosetta mission [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA (CC BY-SA 4.0)]
- "This seems to be one of the largest cliff collapses we've seen on the comet during Rosetta's lifetime, with an area of about 2000 m2 collapsing," said Ramy, also speaking at EPSC-DPS today.
- During perihelion passage, the southern hemisphere of the comet was subjected to high solar input, resulting in increased levels of activity and more intensive erosion than elsewhere on the comet.
- "Inspection of before and after images allow us to ascertain that the scarp was intact up until at least May 2015, for when we still have high enough resolution images in that region to see it," says Graham, an undergraduate student working with Ramy to investigate Rosetta's vast image archive.
- "The location in this particularly active region increases the likelihood that the collapsing event is linked to the outburst that occurred in September 2015."
- Looking in detail at the debris around the collapsed region suggests that other large erosion events have happened here in the past. Ramy and Graham found that the debris includes blocks of variable size ranging up to tens of meters, substantially larger than the boulder population following the Aswan cliff collapse, which is mainly comprised of boulders a few meters diameter.
- "This variability in the size distribution of the fallen debris suggests either differences in the strength of the comet's layered materials, and/or varying mechanisms of cliff collapse," adds Ramy.
- Studying comet changes like these not only gives insight into the dynamic nature of these small bodies on short timescales, but the larger scale cliff collapses provide unique views into the internal structure of the comet, helping to piece together the comet's evolution over longer timescales.
- "Rosetta's datasets continue to surprise us, and it's wonderful the next generation of students are already making exciting discoveries," adds Matt Taylor, ESA's Rosetta project scientist. 86)
Figure 55: Cliff collapse before and after. Before and after a cliff collapse on Comet 67P/Churyumov-Gerasimenko. In the upper panels the yellow arrows show the location of a scarp at the boundary between the illuminated northern hemisphere and the dark southern hemisphere of the small lobe at times before and after the outburst event (September 2014 and June 2016, respectively). The lower panels show close-ups of the upper panels; the blue arrow points to the scarp that appears to have collapsed in the image after the outburst. Two boulders (1and 2) are marked for orientation [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA (CC BY-SA 4.0)]
• August 12, 2019: Last week marked five years since ESA's Rosetta probe arrived at its target, a comet named 67P/Churyumov-Gerasimenko (or 67P/C-G). Tomorrow, 13 August, it will be four years since the comet, escorted by Rosetta, reached its perihelion – the closest point to the Sun along its orbit. This image, gathered by Rosetta a couple of months after perihelion, when the comet activity was still very intense, depicts the nucleus of the comet with an unusual companion: a chunk of orbiting debris (circled). At that time, the spacecraft was at over 400 km away from the comet's center. 87)
Figure 56: Animated sequence of images obtained by ESA's Rosetta probe at Comet 67P/Churyumov-Gerasimenko on 21 October 2015. The sizeable chunk in this view was spotted by astrophotographer Jacint Roger from Spain, who mined the Rosetta archive, processed some of the data, and posted the finished images on Twitter as an animated GIF. Scientists at ESA and in the OSIRIS instrument team are now looking into this large piece of cometary debris in greater detail. Dubbed a ‘Churyumoon' by researcher Julia Marín-Yaseli de la Parra, the chunk appears to span just under 4 m in diameter. - Modelling of the Rosetta images indicates that this object spent the first 12 hours after its ejection in an orbital path around 67P/C-G at a distance of between 2.4 and 3.9 km from the comet's center. Afterwards, the chunk crossed a portion of the coma, which appears very bright in the images, making it difficult to follow its path precisely; however, later observations on the opposite side of the coma confirm a detection consistent with the orbit of the chunk, providing an indication of its motion around the comet until 23 October 2015. Scientists have been studying and tracking debris around 67P/C-G since Rosetta's arrival in 2014. The object pictured in this sequence is likely the largest chunk detected around the comet, and will be subject to further investigations [image credit: ESA/Rosetta/MPS/OSIRIS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA/J. Roger (CC BY-SA 4.0)]
- Comet 67P/C-G is a dusty object. As it neared its closest approach to the Sun in late July and August 2015, instruments on Rosetta recorded a huge amount of dust enshrouding the comet. This is tied to the comet's proximity to our parent star, its heat causing the comet's nucleus to release gases into space, lifting the dust along. Spectacular jets were also observed, blasting more dust away from the comet. This disturbed, ejected material forms the ‘coma', the gaseous envelope encasing the comet's nucleus, and can create a beautiful and distinctive tail.
- A single image from Rosetta's OSIRIS instrument can contain hundreds of dust particles and grains surrounding the 4 km-wide comet nucleus. Sometimes, even larger chunks of material left the surface of 67P/C-G – as shown here.
- The sizeable chunk in this view was spotted a few months ago by astrophotographer Jacint Roger from Spain, who mined the Rosetta archive, processed some of the data, and posted the finished images on Twitter as an animated GIF. He spotted the orbiting object in a sequence of images taken by Rosetta's OSIRIS narrow-angle camera on 21 October 2015. At that time, the spacecraft was at over 400 km away from 67P/C-G's center. The animated sequence is available for download here.
• April 26, 2019: Two-and-a-half years have passed since the operational phase of the Rosetta mission came to an end in September 2016. However, scientific evaluation of the enormous amounts of data from the instruments on the spacecraft and the Philae lander is still ongoing. The team of scientists working on the VIRTIS instrument have now published new findings relating to the surface temperature and thermal effects on the 'duck-shaped' Comet 67P / Churyumov-Gerasimenko, Germany's scientific contributions to VIRTIS are led by the German Aerospace Center (DLR). 88) 89)
- The Visible InfraRed and Thermal Imaging Spectrometer (VIRTIS) acquired infrared images of the comet from on board the Rosetta orbiter during August and September 2014, approximately one year before the comet reached perihelion – the point in its orbit closest to the Sun. During the period under consideration, the comet was still distant from the Sun, and its level of activity was low. The researchers converted the images into thermal maps.
- Temperature is the most important parameter for deriving the gas and dust activity typical of comets. First, the VIRTIS team measured the average temperature of the comet's nucleus on its daytime side. While the average surface temperature over the two months was approximately minus 60ºC, the scientists also identified places that were significantly warmer, at around minus 43ºC. These included a cavity in the surface, where the inner walls reflected the thermal radiation and thus led to stronger warming, referred to as self-heating.
- Self-heating also occurs at the 'duck's neck' connecting the two lobes of the comet. Temperatures were higher here than the laws of black-body radiation would imply. Assuming a dust-dominated surface a few millimeters thick and minimal sublimation of volatile substances, self-heating is attributable to surface roughness. The self-heating effect is enhanced by the striking concave shape of the 'neck'.
- Another significant finding concerns the thermal gradients caused by sudden shadows cast alternately onto the 'neck' by the two lobes of the comet during solar illumination. These localized shadows on the 'neck' created extreme temperature differences within the space of just a few minutes, which might be 10 times greater than normal daily variations in temperature on other areas of the surface. "To better investigate seasonal temperature effects on the nucleus, we concentrated on a region named Imhotep, which is relatively flat and far from the 'neck', and where the self-heating effect is significantly lower," says Gabriele Arnold of the DLR Institute of Planetary Research. "For this area, we compared the observations performed by VIRTIS with those of the Microwave Instrument for the Rosetta Orbiter (MIRO), another instrument on board Rosetta. MIRO made it possible to measure the temperature in larger depressions on the comet. The findings of the two instruments can be explained by the theory that the Imhotep region has a thin surface layer consisting mainly of loose dust."
- Imhotep was also observed a few months later, when the comet was much closer to the Sun. The temperature values obtained by VIRTIS were much higher than before, but lower than expected, given that the scientists were working on the assumption that the surface layer consisted only of loose dust. This led the researchers to conclude that the composition of the uppermost layers must have changed over time. The quantity of volatiles within it must have increased, resulting in a higher degree of sublimation and more intense comet activity. This in turn can cause surface temperatures to be lower than would be reached by a layer consisting solely of dust.
- All the observational evidence suggests a comet nucleus with thermal behavior that is dominated by phenomena associated with the morphology and chemical and physical state of the thin uppermost surface layer, which is only a few centimeters thick. In the subsurface, the nucleus is thought to remain essentially unchanged and has only been weakly influenced by previous approaches to the Sun.
- Gabriele Arnold sums up: "The work that has just been published shows that the ongoing evaluation of the large quantity of data acquired will continue to provide unique findings for comet research and the study of the early Solar System, even years after the end of the Rosetta mission."
Figure 57: Measured and modelled surface temperature (image credit: VIRTIS study team, DLR)
• April 23, 2019: From a distance of five million kilometers to within 20 meters, ESA's Rosetta spacecraft captured images of Comet 67P/Churyumov-Gerasimenko from all angles. 90)
- Between the first and the last images lies one of humankind's greatest space adventures to rendezvous with and follow a comet as it orbited the Sun, and deploy a lander to its surface.
- Figure 58 is just one of almost 70,000 images taken with Rosetta's high-resolution imaging system OSIRIS that are now available via a new online and mobile-friendly ‘comet viewer' created in a joint project with the Department of Information and Communication at Flensburg University of Applied Sciences, and the Max Planck Institute for Solar System Research, who lead the OSIRIS team.
- The image viewer hosts the full archive, but also has subsections organizing image sets into themes: for example, images showing towering cliffs and bizarre cracks on the comet surface, or those focusing on spectacular dust fountains as the comet launched gas and dust jets into space as its surface ices were warmed as it came closer to the Sun on its orbit.
- The collection of OSIRIS images captured the farewell of lander Philae as it dropped towards the surface of the comet, and later, towards the end of the mission, the feverish search for the hidden robot.
- Within the new comet viewer, each of the nearly 70,000 images is supplemented with the date on which it was taken, the distance to the comet, and a short accompanying text briefly describing what is seen in the image. The images can be downloaded in full resolution and can also be directly shared to Twitter and Facebook.
- For users who wish to delve deeper or use the archive for research purposes, the images are also available in scientific data format; in addition, there is information available on the filters used, focal lengths, and exposure times as well as references to the scientific documentation and evaluation software.
- The tool supplements the official ESA Archive Image Browser which also hosts the images taken by Rosetta's navigation camera made available throughout the mission, and ESA's Planetary Science Archive, for which the OSIRIS image archive was completed in June 2018.
- Read more: https://www.mps.mpg.de/One-comet-70000-images
Figure 58: Seen from afar, the comet is usually likened to a duck in shape, but in this enchanting close-up view its profile resembles that of a cat's face seen side-on. The two ‘ears' of the cat make up the twin peaks either side of the ‘C. Alexander Gate' – named for US Rosetta Project Scientist Claudia Alexander who passed away in July 2015. These impressive cliffs lie at the border between the Serqet and Anuket regions on the comet's head. The image was taken on 6 October 2014 from a distance of 18.6 km to the comet [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA (CC BY-SA 4.0)]
• April 12, 2019: ESA's Rosetta mission was an incredible feat of science and engineering. Studying a comet up close, and even landing a probe on its surface, was an apt demonstration of ESA's abilities. Even though the mission ended in 2016, its benefits live on in the ESA Academy's Rosetta Science Operations Scheduling Legacy Workshops. The 2019 workshop has just been completed by 30 university students from 12 different ESA Member States and Canada. 91)
- "The friendly and international environment, together with the knowledge acquired during these four days were the best parts of the workshop," reviewed a Spanish student from the Polytechnic University of Catalonia. "This workshop was one of the few opportunities that I have had, as a student, to meet international science operation experts with the same interests and motivations and a common goal, while learning from their shared experiences in a mission that every space technology student is very fond of. I also found important the fact that this expert-student flow of information did not happen only during the lectures, but also in less formal scenarios, such as over coffee breaks or dinner. The workshop exceeded all my expectations and I had no idea how much I could learn in just four days. What an amazing week!"
- The students were excited to learn about science operations scheduling, and how it was planned for the Rosetta mission. A combination of lectures and exercises using the ESA's Mission Analysis and Payload Planning Software (MAPPS) kept each day varied.
- The students were divided into groups of three, each with a different background. They were supported by the experts that had scheduled the Rosetta mission. Various scenarios were proposed, such as Rosetta's arrival at the comet, and the search for the Philae lander after it bounced on the comet's surface. These situations provided context, and gave ample opportunity to both utilize the planning software, and draw upon the experience of the experts. In one scenario, students had to schedule the pictures that needed to be taken for Philae's descent, and then scour the Rosetta archive to find and analyze them.
- "During this week I embarked on a journey with Rosetta, alongside the people that dedicated their careers to see this mission succeed," said a Portuguese student from the Delft University of Technology. "From arriving at the comet to its final descent, Rosetta unveiled the secrets of 67P, and produced invaluable science during its lifetime. Hopefully the students involved in the workshop will be the future scientists and engineers exploring our Solar System and beyond, following the footsteps of Rosetta!"
- The accompanying lectures were designed to support and complement the exercises. They also allowed the students to gain insight into the many and varied aspects of the Rosetta mission. Some were broad, such as an overview of Rosetta; while others were more specific, such as planning the end of mission operations.
- Throughout the week, each student group had the opportunity to present the results of an exercise to the rest of the participants. This allowed them in-depth discussions, which were evaluated so that the students could claim ECTS credit(s) on their return to their respective universities. In addition, the students enjoyed a guided tour of ESEC-Redu and the PROBA control and operations rooms, which proved to be particularly illuminating.
Figure 59: This second edition of the workshop was held from 2 to 5 April 2019 at ESA Academy's Training and Learning Facility in ESEC-Galaxia, Belgium.. Present to share expertise with the students were seven experts, scientists and engineers, from ESA and the Max Planck Institute for Solar System Research. Among them were the Rosetta Project Scientist and Spacecraft Operations Manager. Personally involved with the Rosetta mission, the trainers had unrivalled knowledge and invaluable viewpoints, and they peppered the week with stories and anecdotes (image credit: ESA)
- A Spanish student from the University Carlos III of Madrid found this to be a formative experience: "There was T. S. Eliot quote I read a long time ago, which goes ‘Only those who risk going too far can possibly find out how far one can go'. I have always tried to follow that ideal. The second edition of the Rosetta Science Operations Scheduling Legacy Workshop proved me that ESA not only follow that ideal, but also achieve it. I truly wish one day I will work at ESA."
Figure 60: Photo of the students and trainers at the ESA Academy's Training Center (image credit: ESA)
• February 18, 2019: Feeling stressed? You're not alone. ESA's Rosetta mission has revealed that geological stress arising from the shape of Comet 67P/Churyumov–Gerasimenko has been a key process in sculpting the comet's surface and interior following its formation. 92)
Figure 61: Single frame enhanced NavCam image taken on 27 March 2016, when Rosetta was 329 km from the nucleus of Comet 67P/Churyumov-Gerasimenko. The scale is 28 m/pixel and the image measures 28.7 km across (image credit: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0)
- Small, icy comets with two distinct lobes seem to be commonplace in the Solar System, with one possible mode of formation a slow collision of two primordial objects in the early stages of formation some 4.5 billion years ago. A new study using data collected by Rosetta during its two years at Comet 67P/C-G has illuminated the mechanisms that contributed to shaping the comet over the following billions of years.
- The researchers used stress modelling and three-dimensional analyses of images taken by Rosetta's high resolution OSIRIS camera to probe the comet's surface and interior.
- "We found networks of faults and fractures penetrating 500 meters underground, and stretching out for hundreds of meters," says lead author Christophe Matonti of Aix-Marseille University, France.
- "These geological features were created by shear stress, a mechanical force often seen at play in earthquakes or glaciers on Earth and other terrestrial planets, when two bodies or blocks push and move along one another in different directions. This is hugely exciting: it reveals much about the comet's shape, internal structure, and how it has changed and evolved over time."
- The model developed by the researchers found shear stress to peak at the center of the comet's ‘neck', the thinnest part of the comet connecting the two lobes.
- "It's as if the material in each hemisphere is pulling and moving apart, contorting the middle part – the neck – and thinning it via the resulting mechanical erosion," explains co-author Olivier Groussin, also of Aix-Marseille University, France.
- "We think this effect originally came about because of the comet's rotation combined with its initial asymmetric shape. A torque formed where the neck and ‘head' meet as these protruding elements twist around the comet's center of gravity."
- The observations suggest that the shear stress acted globally over the comet and, crucially, around its neck. The fact that fractures could propagate so deeply into 67P/C-G also confirms that the material making up the interior of the comet is brittle, something that was previously unclear.
- "None of our observations can be explained by thermal processes," adds co-author Nick Attree of the University of Stirling, UK. "They only make sense when we consider a shear stress acting over the entire comet and especially around its neck, deforming and damaging and fracturing it over billions of years."
- Sublimation, the process of ices turning to vapor and resulting in comet dust being dragged out into space, is another well-known process that can influence a comet's appearance over time. In particular, when a comet passes closer to the Sun, it warms up and loses its ices more rapidly – perhaps best visualized in some of the dramatic outbursts captured by Rosetta during its time at Comet 67P/C–G.
- The new results shed light on how dual-lobe comets have evolved over time.
Figure 62: These images show how Rosetta's dual-lobed comet, 67P/Churyumov-Gerasimenko, has been affected by a geological process known as mechanical shear stress. The comet's shape is shown in the left two diagrams from top and side perspectives, while the four frames on the right zoom in on the part marked by the overlaid black box (the comet's ‘neck'). The red arrow points to the same spot in both images, seen from a different perspective. - The two central frames show this part of the neck as imaged by Rosetta's OSIRIS camera, and used in a new study exploring how the comet's shape has evolved over time. The two frames on the right highlight different features on the comet using these images as a background canvas. Red lines trace fracture and fault patterns formed by shear stress, a mechanical force often seen at play in earthquakes or glaciers on Earth and other terrestrial planets. This occurs when two bodies or blocks push and move along one another in different directions, and is thought to have been induced here by the comet's rotation and irregular shape. Green marks indicate terraced layers [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; C. Matonti et al. (2019)] 93) 94)
Figure 63: This diagram illustrates the evolution of Rosetta's dual-lobed comet, 67P/Churyumov-Gerasimenko, over the past 4.5 billion years [image credit: C. Matonti et al (2019)]
Legend to Figure 63: The comet is thought to have formed this long ago in the primordial disc of the Solar System, perhaps as two small objects slowly collided and stuck together. Comets form in the icy outer Solar System and are stored there in vast clouds before beginning their journey inwards; comet 67P/C-G is thought to have entered the giant planet region hundreds of thousands to millions of years of ago. By this point a form of geological erosion named mechanical shear stress had taken hold, and was the dominant process sculpting and shaping the comet's surface and interior. A new study using data from Rosetta found this stress to peak in the region connecting the two lobes of the comet: the ‘neck'. This neck bore the brunt of mechanical erosion, fracturing and thinning over time – as shown in the diagram by the cross-hatched lines.
The final steps cover the time period from tens of thousands of years ago to present day, a period during which sublimation erosion was dominant in shaping the comet's surface and interior. This kind of erosion takes place as the Sun warms ices within the comet, causing the ice to turn to gas and escape to space, carrying cometary material along with it. This weakened the comet's neck further, and the force grew stronger as it travelled inwards from Jupiter's orbit towards Mars.
It is important to note that the red arrows do not imply cometary rotation; instead, they represent shear deformation, and illustrate the torque generated at the neck.
- Comets are thought to have formed in the earliest days of the Solar System, and are stored in vast clouds at its outer edges before beginning their journey inwards. It would have been during this initial ‘building' phase of the Solar System that 67P/C-G got its initial shape.
Figure 64: First impressions of the Kuiper Belt object Ultima Thule (left) revealed a surprisingly familiar appearance to the comet that ESA's Rosetta spacecraft explored for more than two years (right), [image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute; right: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0]
Legend to Figure 64: First impressions of the Kuiper Belt object Ultima Thule (left) revealed a surprisingly familiar appearance to the comet that ESA's Rosetta spacecraft explored for more than two years (right). - NASA's New Horizons flew by Ultima Thule on 1 January 2019, with subsequent images and data suggesting that its two lobes are rather more 'squashed' like a pancake, with respect to Comet 67P/Churyumov-Gerasimenko. Ultima Thule, which sits beyond the orbit of Neptune in the outskirts of the Solar System, is about 34 km long, with the two lobes measuring about 19.5 and 14.2 km across. — By comparison, Comet 67P/C-G's two lobes measure 4.1 x 3.3 x 1.8 km and 2.6 x 2.3 x 1.8 km. The comet likely originated from the Kuiper Belt and now orbits around the Sun on a 6.5 year journey that takes it from just beyond the orbit of Jupiter at its most distant, to between the orbits of Earth and Mars at its closest.
- Excitingly, NASA's New Horizons probe recently returned images from its flyby of Ultima Thule, a trans-Neptunian object located in the Kuiper belt, a reservoir of comets and other minor bodies at the outskirts of the Solar System.
- The data revealed that this object also has a dual-lobed shape, even though somewhat flattened with respect to Rosetta's comet.
- "The similarities in shape are promising, but the same stress structures don't seem to be apparent in Ultima Thule," comments Christophe.
- As more detailed images are returned and analyzed, time will tell if it has experienced a similar history to 67P/C-G or not.
- "Comets are crucial tools for learning more about the formation and evolution of the Solar System," says Matt Taylor, ESA's Rosetta Project Scientist.
- "We've only explored a handful of comets with spacecraft, and 67P is by far the one we've seen in most detail. Rosetta is revealing so much about these mysterious icy visitors and with the latest result we can study the outer edges and earliest days of the Solar System in a way we've never been able to do before."
• February 11, 2019: It is always reassuring to catch that first familiar glimpse of home after a great adventure, but for our space-faring satellites the return visit is brief and of a practical nature: to use the planet's immense gravity to sling it onto a new trajectory. 95)
- These ‘gravity assists' are fleeting encounters, but enough to change the spacecraft's speed and direction such that it can eventually enter orbit around another world.
- This delicate view of Earth was captured in 2007 on the second of three Earth flybys made by ESA's comet-chasing Rosetta spacecraft on its ten year journey to Comet 67P/Churyumov-Gerasimenko. The spacecraft also got a boost from Mars to set it on course with its destination.
- The first ever interplanetary gravity slingshot took place on 5 February 1974, when NASA's Mariner 10 flew past Venus en route to flybys of Mercury.
Figure 65: The First Spacecraft to Use Gravity Assist - Mariner 10 (video credit: NASA) 96)
- The ESA-JAXA BepiColombo mission – whose name is inherited from Giuseppe Colombo who originally proposed to NASA the interplanetary trajectories that would allow Mariner-10 multiple Mercury flybys by using gravity assists at Venus – will make nine flybys of Earth, Venus and Mercury to reach the innermost planet and eventually enter orbit about it.
- Similarly, ESA's upcoming Solar Orbiter mission will use Venus gravity assists to change its inclination to get a better look at the Sun's poles. And ESA's Jupiter Icy Moons Explorer will first dive into the inner Solar System to use Earth, Venus and Mars to set course for the gas giant Jupiter.
- But Earth remains home to a fleet of satellites busy performing a number of different activities from orbit: while some are peering far away into the cosmos, our Earth Observation missions are watching diligently over our precious planet, taking its ‘pulse' and helping us to better understand how to care for it. The Sun-illuminated crescent seen around Antarctica in this beautiful image (Figure 66) certainly evokes a feeling of fragility and reminds us of our special place in space.
Figure 66: The image was taken by the OSIRIS camera on Rosetta about two hours before closest approach during the 13 November 2007 flyby, when the spacecraft was 75,000 km from Earth. The mission went on to become the first to rendezvous with and land on a comet, and the first to follow and study a comet on its orbit around the Sun (image credit: ESA ©2005 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/ UPM/DASP/IDA)
• January 31, 2019: Engineering models are an important part of spacecraft operations – acting as faithful and realistic testbeds for all sorts of trials and tricks too risky to attempt, first-go, on the original. Models like this also serve as mementos of our human endeavors in space, which are so often hard to visualize, and even harder to get close to. 97)
- The original Rosetta probe carried out its final maneuver at 20:50 GMT (22:50 CEST) on 29 September 2016, setting itself down on comet 67P/Churyumov–Gerasimenko and sending its final image from just 24 or so meters above the surface.
- While we no longer receive updates from the plucky comet-chaser, our 'super model' – seen here at night in its new glassed-in pavilion – reminds us every day of what a remarkable achievement this was.
Figure 67: This life-size copy of the world-famous Rosetta spacecraft is living out its retirement at ESA's European Space Operations Center in Darmstadt, Germany (image credit: ESA/J. Mai)
• December 17, 2018: An old friend of ESA, Comet 46P/Wirtanen, is crossing our skies this month. — The comet nucleus is at the core of the brightest spot at the center of the image, and the green diffuse cloud is its coma. The green color is caused by molecules – mainly CN (cyanogen) and C2 (diatomic carbon) – that are ionized by sunlight as the comet approaches the Sun. A hint of the comet's tail is visible to the upper left; the diagonal stripes are star trails. 98) 99)
- A bright comet with a period of 5.5 years, 46P had been chosen in the 1990s as the target of ESA's Rosetta mission. However, a launch delay from 2003 to 2004 meant the spacecraft would not be able to rendezvous with that comet at its closest approach to the Sun in 2013, prompting the Rosetta team to select a new target, the now famed 67P/Churyumov–Gerasimenko.
- Comet 46P was at perihelion, the closest point to the Sun along its orbit, on 12 December, and kept moving towards our planet, reaching the closest distance to Earth on 16 December.
- Astronomers across the world – professional, student and amateur alike – have been observing the comet recently, and will keep doing so in coming weeks as it moves away from the Sun along its orbit.
Figure 68: This image was taken by Wouter Van Reeven at ESA/ESAC (European Space Astronomy Center) near Madrid, Spain, on 14 December 2018. It is a composite of 132 individual images, each with a 10 second exposure, using a William Optics ZS 71 ED (71 mm refractor) telescope and a Canon EOS 700D DSLR camera (ISO: 3200). The field of view spans 2.8º x 1.8º (image credit: ESA/ESAC Astronomy Club / W. Van Reeven)
• December 12, 2018: A new study reveals that, contrary to first impressions, Rosetta did detect signs of an infant bow shock at the comet it explored for two years – the first ever seen forming anywhere in the Solar System. 100) 101)
- From 2014 to 2016, ESA's Rosetta spacecraft studied Comet 67P/Churyumov-Gerasimenko and its surroundings from near and far. It flew directly through the ‘bow shock' several times both before and after the comet reached its closest point to the Sun along its orbit, providing a unique opportunity to gather in situ measurements of this intriguing patch of space.
- Comets offer scientists an extraordinary way to study the plasma in the Solar System. Plasma is a hot, gaseous state of matter comprising charged particles, and is found in the Solar System in the form of the solar wind: a constant stream of particles flooding out from our star into space.
- As the supersonic solar wind flows past objects in its path, such as planets or smaller bodies, it first hits a boundary known as a bow shock. As the name suggests, this phenomenon is somewhat like the wave that forms around the bow of a ship as it cuts through choppy water.
Figure 69: Artist's impression of the infant bow shock detected by ESA's Rosetta spacecraft at Comet 67P/Churyumov-Gerasimenko. The spacecraft detected signs of a forming bow shock around 50 times closer to the comet's nucleus than anticipated in the case of 67P. This boundary was observed to be asymmetric, wider than the fully developed bow shocks observed at other comets, and moving in unexpected ways. - Rosetta detected the bow shock as the boundary changed position responding to the upstream magnetic field flipping from one side to the other. As a result, the spacecraft found itself alternatively outside of the shock (left frame) and behind it (right frame). It is the first time a bow shock in such an early formation stage has been detected anywhere in the Solar System (image credit: ESA)
- Bow shocks have been found around comets, too – Halley's comet being a good example. Plasma phenomena vary as the medium interacts with the surrounding environment, changing the size, shape, and nature of structures such as bow shocks over time.
- Rosetta looked for signs of such a feature over its two-year mission, and ventured over 1500 km away from 67P's center on the hunt for large-scale boundaries around the comet – but apparently found nothing.
- "We looked for a classical bow shock in the kind of area we'd expect to find one, far away from the comet's nucleus, but didn't find any, so we originally reached the conclusion that Rosetta had failed to spot any kind of shock," says Herbert Gunell of the Royal Belgian Institute for Space Aeronomy, Belgium, and Umeå University, Sweden, one of the two scientists who led the study.
- "However, it seems that the spacecraft actually did find a bow shock, but that it was in its infancy. In a new analysis of the data, we eventually spotted it around 50 times closer to the comet's nucleus than anticipated in the case of 67P. It also moved in ways we didn't expect, which is why we initially missed it."
- On 7 March 2015, when the comet was over twice as far from the Sun as the Earth and heading inwards towards our star, Rosetta data showed signs of a bow shock beginning to form. The same indicators were present on its way back out from the Sun, on 24 February 2016.
- This boundary was observed to be asymmetric, and wider than the fully developed bow shocks observed at other comets.
- "Such an early phase of the development of a bow shock around a comet had never been captured before Rosetta," says co-lead Charlotte Goetz of the Institute for Geophysics and Extraterrestrial Physics in Braunschweig, Germany.
- "The infant shock we spotted in the 2015 data will have later evolved to become a fully developed bow shock as the comet approached the Sun and became more active – we didn't see this in the Rosetta data, though, as the spacecraft was too close to 67P at that time to detect the ‘adult' shock. When Rosetta spotted it again, in 2016, the comet was on its way back out from the Sun, so the shock we saw was in the same state but ‘unforming' rather than forming."
- Herbert, Charlotte, and colleagues explored data from the Rosetta Plasma Consortium, a suite of instruments comprising five different sensors to study the plasma surrounding Comet 67P. They combined the data with a plasma model to simulate the comet's interactions with the solar wind and determine the properties of the bow shock.
- The scientists found that, when the forming bow shock washed over Rosetta, the comet's magnetic field became stronger and more turbulent, with bursts of highly energetic charged particles being produced and heated in the region of the shock itself. Beforehand, particles had been slower-moving, and the solar wind had been generally weaker – indicating that Rosetta had been ‘upstream' of a bow shock.
- "These observations are the first of a bow shock before it fully forms, and are unique in being gathered on-location at the comet and shock itself," says Matt Taylor, ESA Rosetta Project Scientist. "This finding also highlights the strength of combining multi-instrument measurements and simulations. It may not be possible to solve a puzzle using one dataset, but when you bring together multiple clues, as in this study, the picture can become clearer and offer real insight into the complex dynamics of our Solar System – and the objects in it, like 67P."
Figure 70: This animation shows a simulated view of ESA's Rosetta spacecraft at its target, Comet 67P/Churyumov-Gerasimenko, on 24 February 2016 (video credit: ESA/Rosetta/RPC; H. Gunell et al (2018)
Legend to Figure 70: The comet is represented in grey in the left-hand frame, while the small cyan satellite represents the simulated Rosetta spacecraft. The simulation reconstructs the plasma conditions when Rosetta spotted an infant bow shock in the process of ‘unforming': this infant bow shock can be seen as the sweeping red-yellow curve. The colors show the proton density for the region – the number of protons found within a cubic cm – as indicated in the bar at the top, with red-yellow being a high and black-blue a low density. In this frame, the Sun is on the right-hand side, meaning that the solar wind flows from right to left.
As Rosetta circles around the comet in this simulation, crossing the bow shock twice, the associated patterns observed in proton and water ion abundances and energies can be seen in the upper and central panels on the right, with the moving cyan line representing Rosetta's location. This demonstrates how the major types of charged particles in the vicinity of the forming bow shock change along with Rosetta's simulated location, and how the distribution of protons becomes wider in the region of the shock than in the surrounding solar wind (shown in the two vertical stripes of red in the top right panel). The bars to the right indicate the differential particle flux to the instrument – the number of particles passing through a given area per unit time and solid angle (a measure of the instrument's field of view) – with red being high and black being low. The scales to the left indicate particle energies.
The magnetic field strength around the comet can be seen in the bottom-right panel. As the simulated Rosetta crosses the shock, two spikes appear in the field strength, which also correlate with the shock-related effects seen in the upper two right-hand panels.
• October 01, 2018: On 30 September 2016, ESA's Rosetta spacecraft came closer than ever to the target it had studied from afar for more than two years, concluding its mission with a controlled impact onto the surface of Comet 67P/Churyumov-Gerasimenko (67P/C-G). 102)
- This second comet landing followed the pioneering endeavour of Rosetta's lander, Philae, which became the first probe to successfully touch down on a comet on 12 November 2014.
- With a suite of 11 scientific instruments on board, Rosetta collected an impressive amount of images and other data at this now iconic comet, scanning its surface, probing its interior, scrutinizing the gas and dust in its surroundings, and exploring its plasma environment. Scientists have been using these measurements to advance our understanding of comets as well as of the history of our Solar System.
- This image shows a portion of 67P/C-G as viewed by Rosetta on 22 September 2014, only one and a half months after the spacecraft had made its rendezvous with the comet. At the time, the spacecraft was 28.2 km from the comet center (around 26.2 km from the surface). Amateur astronomer Jacint Roger Perez, from Spain, selected and processed this view by combining three images taken in different wavelengths by the OSIRIS narrow-angle camera on Rosetta.
- Seen in the center and left of the frame is Seth, one of the geological regions on the larger of the two comet lobes, which declines towards the smoother Hapi region on the comet's ‘neck' that connects the two lobes. The landscape in the background reveals hints of the Babi and Aker regions, both located on the large lobe of 67P/C-G. For a wider image of this region in the overall context of the comet see here.
- The sharp profile in the lower part of the image shows the Aswan cliff, a 134 m-high scarp separating the Seth and Hapi regions. Observations performed by Rosetta not long before the comet's perihelion, which took place on 13 August 2015, revealed that a chunk of this cliff had collapsed – a consequence of increased activity as the comet drew closer to the Sun along its orbit.
Figure 71: An evocative image of Rosetta's comet to recall the end of its trailblazing mission two years ago (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; J. Roger – CC BY SA 4.0)
• August 6, 2018: Over its lifetime Rosetta extensively mapped the comet's surface, which has since been divided into 26 geological regions named after Ancient Egyptian deities. The entire comet has been likened to a duck in shape, with a small ‘head' attached to a larger ‘body'. 103)
Figure 72: This image shows a section of 67P/C-G as viewed by Rosetta's high-resolution camera OSIRIS on 10 February 2016. Amateur astronomer Stuart Atkinson, from the UK, selected and processed this view from the OSIRIS image archive. It is a crop of a larger image that shows a slightly wider view of the comet's ‘Bes' region on body of the comet, which takes its name from the protective deity of households, children and mothers (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA – CC BY SA 4.0; Acknowledgement: S Atkinson)
- The image shows the uneven, shadowed surface of the comet in detail; particularly prominent just to the right of center is an upright feature surrounded by scattered depressions, rocky outcrops and debris.
• July 18, 2018: As Japan's Hayabusa-2 drew closer to its target Ryugu asteroid, a strange new planetoid came into view – but one with a somewhat familiar shape. This distinct ‘spinning top' asteroid class has been seen repeatedly in recent years, and might give a foretaste of things to come for ESA's proposed Hera mission. 104)
- Hayabusa2 is currently just 20 km away from the 900-m wide asteroid. The view from its navigation camera reveals a spinning body with an enlarged ridge of material around its equator – a bulge suggesting Ryugu may once have been spinning much faster.
Figure 73: Image of Ryugu, captured with ONC-T (Optical Navigation Camera – Telescopic) at 12:50 p.m. (JST), June 26, 2018 (image credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST)
- As ESA's space scientist Michael Küppers followed Hayabusa-2's approach, he recalled Europe's own asteroid first encounter, just under a decade ago on 5 September 2008, when Rosetta performed a flyby of the Steins asteroid en route to its final destination, comet 67P/Churyumov-Gerasimenko.
Figure 74: Asteroid Steins seen from a distance of 800 km, taken by the OSIRIS imaging system from two different perspectives. The effective diameter of the asteroid is 5 km, approximately as predicted. At the top of the asteroid (as shown in this image), a large crater, approximately 1.5-km in size, can be seen. Scientists were amazed that the asteroid survived the impact that was responsible for the crater (image credit: ESA ©2008 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA) 105)
Figure 75: Sequential views from Japan's Hayabusa-2 mission as it approached the Ryugu asteroid during June 2018 (image credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu and AIST)
- "At 6 km across, Šteins (Steins) was much larger, but had a similar diamond shape," says Michael. "Personally I wasn't surprised to see this again with Ryugu, because it has turned up with many smaller asteroids in recent years. The current thinking is this shape is due to asteroids being set spinning rapidly, and the resulting centrifugal force moving material away from the poles and towards the equator. As for what causes such a spin, this probably comes down to the so-called YORP (Yarkovsky–O'Keefe–Radzievskii–Paddack) effect."
- The YORP effect, named after four different researchers who worked on asteroids, is triggered by the warming of asteroids by sunlight. The asteroids re-radiate this energy as heat, which gives rise to a tiny amount of thrust. Eventually Newton's Third Law – ‘every action has an equal and opposite reaction' – exerts itself. And due to their irregular shapes, some parts of asteroids generate more thrust than others, leading to a turning force like wind past a windmill.
- "The resulting centrifugal force could continue to the point that material is actually thrown out into space," adds Michael, "leading to the creation of the binary or multiple asteroid systems that make up 15% of all asteroids so far discovered. Some might also crumble apart altogether. For larger asteroids YORP is less likely to influence shape, as their ratio between mass and surface area is much higher."
- Today Michael is serving as project scientist on ESA's Hera mission study, planned as humankind's first mission to a binary asteroid system if approved at next year's ESA Council meeting at ministerial level. His role is to work with external scientists to come up with mission requirements, and make early plans for operations and data analysis.
- Hera's target is the Didymos system, with a 780 m main body orbited by a smaller 160 m ‘Didymoon'. NASA's DART spacecraft will impact this smaller body in 2022 to measurably shift its orbit, ahead of Hera's arrival in 2026 – the two missions combining in an audacious, full-scale planetary defence test.
• June 21, 2018: All high-resolution images and the underpinning data from Rosetta's pioneering mission at Comet 67P/Churyumov-Gerasimenko are now available in ESA's archives, with the last release including the iconic images of finding lander Philae, and Rosetta's final descent to the comet's surface. 106)
- The Archive Image Browser also hosts images captured by the spacecraft's Navigation Camera, while the Planetary Science Archive contains publicly available data from all eleven science instruments onboard Rosetta – as well as from ESA's other Solar System exploration missions.
- The final batch of high-resolution images from Rosetta's OSIRIS camera covers the period from late July 2016 to the mission end on 30 September 2016. It brings the total count of images from the narrow- and wide-angle cameras to nearly 100 000 across the spacecraft's 12 year journey through space, including early flybys of Earth, Mars and two asteroids before arriving at the comet.
- The spacecraft's trajectory around the comet changed progressively during the final two months of the mission, bringing it closer and closer at its nearest point along elliptical orbits. This allowed some spectacular images to be obtained from within just two kilometers of the surface, highlighting the contrasts in exquisite detail between the smooth and dusty terrain, and more consolidated, fractured comet material.
- One particularly memorable sets of images captured in this period were those of Rosetta's lander Philae following the painstaking effort over the previous years to determine its location. With Rosetta flying so close, challenging conditions associated with the dust and gas escaping from the comet, along with the topography of the local terrain, caused problems with getting the best line-of-sight view of Philae's expected location, but the winning shot was finally captured just weeks before the mission end.
- In the mission's last hours as Rosetta moved even closer towards the surface of the comet, it scanned across an ancient pit and finally sent back images showing what would become its resting place. Even after the spacecraft was silent, the team were able to reconstruct a last image from the final telemetry packets sent back when Rosetta was within about 20 m of the surface.
• January 22, 2018: Perhaps you live in a part of the world where you regularly experience snow storms or even dust storms. But for many of us, the weather forms a natural part of everyday conversation – more so when it is somewhat extreme, like a sudden blizzard that renders transport useless or makes you feel highly disoriented as you struggle to fix your sights on recognizable landmarks.
- ESA's Rosetta mission had a similar experience, for more than two years, as it flew alongside Comet 67P/Churyumov–Gerasimenko between 2014 and 2016. It endured the endless impacts of dust grains launched by gaseous outpourings as the comet's surface ices were warmed by the heat of the Sun, evaporating into space and dragging the dust along. 107)
- The image of Figure 76 was taken two years ago, on 21 January 2016, when Rosetta was flying 79 km from the comet. At this time Rosetta was moving closer following perihelion in the previous August, when the comet was nearer to the Sun and as such at its most active, meaning that Rosetta had to operate from a greater distance for safety.
- As can be seen from the image, the comet environment was still extremely chaotic with dust even five months later. The streaks reveal the dust grains as they passed in front of Rosetta's camera, captured in the 146 second exposure.
- Excessive dust in Rosetta's field of view presented a continual risk for navigation: the craft's startrackers used a star pattern recognition function to know its orientation with respect to the Sun and Earth. On some occasions flying much closer to the comet, and therefore through denser regions of outflowing gas and dust, the startrackers locked on to dust grains instead of stars, creating pointing errors and in some cases putting the spacecraft in a temporary safe mode.
- Despite its dangers, the dust was of high scientific interest: three of Rosetta's instruments studied tens of thousands of grains between them, collectively analyzing their composition, their mass, momentum and velocity, and profiling their 3D structure. Studying the smallest and the most pristine grains ejected is helping scientists to understand the building blocks of comets.
- Two years before the image was taken, 20 January 2014, Rosetta was only just waking up from 31 months of deep-space hibernation. It arrived at its destination after 10 years in space in August 2014, and released the lander Philae three months later. Rosetta made unique scientific observations of the comet until reaching its grand finale on 30 September 2016 by descending to the comet's surface. By the end of the mission, more than a hundred thousand images had been taken by the high-resolution OSIRIS camera (including the one shown here) and the navigation camera, the majority of which are available to browse in the Archive Image Browser.
Figure 76: This stormy day image was taken with the OSIRIS narrow angle camera two years ago, on 21 January 2016, when Rosetta was flying 79 km from the comet (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
• October 26, 2017: Last year, a fountain of dust was spotted streaming from Rosetta's comet, prompting the question: how was it powered? Scientists now suggest the outburst was driven from inside the comet, perhaps released from ancient gas vents or pockets of hidden ice. 108)
- The plume was seen by ESA's Rosetta spacecraft on 3 July 2016, just a few months before the end of the mission and as Comet 67P/Churyumov–Gerasimenko was heading away from the Sun at a distance of almost 500 million km.
- "We saw a bright plume of dust blowing away from the surface like a fountain," explains Jessica Agarwal of the Max Planck Institute for Solar System Research in Göttingen, Germany, and lead author of the new paper. "It lasted for roughly an hour, producing around 18 kg of dust every second."
- Alongside a steep increase in the number of dust particles flowing from the comet, Rosetta also detected tiny grains of water-ice. The images showed the location of the outburst: a 10 m-high wall around a circular dip in the surface.
- Previous plumes, collapsing cliffs and similar features have been seen on the comet, but spotting this one was especially fortunate: as well as imaging the location in detail, Rosetta also sampled the ejected material itself.
- "This plume was really special. We have great data from five different instruments on how the surface changed and on the ejected material because Rosetta was, by chance, flying through the plume and looking at the right part of the surface when it happened," adds Jessica. "Rosetta hasn't provided such detailed and comprehensive coverage of an event like this before."
- Initially, scientists thought that the plume might have been surface ice evaporating in the sunlight. However, Rosetta's measurements showed there had to be something more energetic going on to fling that amount of dust into space. "Energy must have been released from beneath the surface to power it," says Jessica. "There are evidently processes in comets that we do not yet fully understand."
- How such energy was released remains unclear. Perhaps it was pressurized gas bubbles rising through underground cavities and bursting free via ancient vents, or stores of ice reacting violently when exposed to sunlight.
- "One of Rosetta's major goals was to understand how a comet works. For example, how does its gaseous envelope form and change over time?" says Matt Taylor, ESA's Rosetta Project Scientist. -"Outbursts are interesting because of this, but we weren't able to predict when or where they would occur – we had to be lucky to capture them. Having full, multi-instrument coverage of an outburst like this and its effect on the surface is really valuable for revealing how these events are driven. Rosetta scientists are now combining measurements from the comet with computer simulations and laboratory work to find out what drives such plumes on comets." 109)
Figure 77: Comet plume (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Figure 78: Comet plume in context (image credit: Comet image (left): ESA/Rosetta/NavCam, CC BY-SA 3.0 IGO; comet model: ESA; all others: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
• September 28, 2017: Scientists analyzing the final telemetry sent by Rosetta immediately before it shut down on the surface of the comet last year have reconstructed one last image of its touchdown site. After more than 12 years in space, and two years following Comet 67P/Churyumov–Gerasimenko as they orbited the Sun, Rosetta's historic mission concluded on 30 September with the spacecraft descending onto the comet in a region hosting several ancient pits. It returned a wealth of detailed images and scientific data on the comet's gas, dust and plasma as it drew closer to the surface. 110)
Figure 79: A final image from Rosetta, shortly before it made a controlled impact onto Comet 67P/Churyumov–Gerasimenko on 30 September 2016, was reconstructed from residual telemetry. The image has a scale of 2 mm/pixel and measures about 1 m across (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
- But there was one last surprise in store for the camera team, who managed to reconstruct the final telemetry packets into a sharp image. "The last complete image transmitted from Rosetta was the one that we saw arriving back on Earth in one piece moments before the touchdown at Sais," says Holger Sierks, principal investigator for the OSIRIS camera at the Max Planck Institute for Solar System Research in Göttingen, Germany. - "Later, we found a few telemetry packets on our server and thought, wow, that could be another image."
- During operations, images were split into telemetry packets aboard Rosetta before they were transmitted to Earth. In the case of the last images taken before touchdown, the image data, corresponding to 23,048 bytes per image, were split into six packets.
- For the very last image the transmission was interrupted after three full packets were received, with 12,228 bytes received in total, or just over half of a complete image. This was not recognized as an image by the automatic processing software, but the engineers in Göttingen could make sense of these data fragments to reconstruct the image.
Figure 80: Rosetta's landing site to scale (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; spacecraft: ESA/ATG medialab)
Legend to Figure 80: In order to give a feeling of scale, this artist impression of the Rosetta spacecraft is superimposed on an OSIRIS wide-angle camera image of the region in which it landed on 30 September 2016. Also marked on the image are the approximate locations of the final two images taken by the spacecraft from around 20 m altitude. The cross indicates the estimated center of touchdown of Rosetta. -The background image measures about 55 m across, while the final images are about 1 m across. For comparison, Rosetta measures 32 m from tip to tip, and its solar panels are a little more than 2 m high each. — Note that the positioning of the spacecraft on the image is not an accurate representation of the actual landing.
Figure 81: Rosetta's last images in context (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Legend to Figure 81: Annotated image indicating the approximate locations of some of Rosetta's final images. Note that due to differences in timing and viewing geometry between consecutive images in this graphic, the illumination and shadows vary.
- Top left: a global view of Comet 67P/Churyumov–Gerasimenko shows the area in which Rosetta touched down in the Ma'at region on the smaller of the two comet lobes. This image was taken by the OSIRIS narrow-angle camera on 5 August 2014 from a distance of 123 km.
- Top right: an image taken by the OSIRIS narrow-angle camera from an altitude of 5.7 km, during Rosetta's descent on 30 September 2016. The image scale is about 11 cm/pixel and the image measures about 225 m across. The final touchdown point, named Sais, is seen in the bottom right of the image and is located within a shallow, ancient pit. Exposed, dust-free terrain is seen in the pit walls and cliff edges. Note the image is rotated 180º with respect to the global context image at top right.
- Middle: an OSIRIS wide-angle camera image taken from an altitude of about 331 m during Rosetta's descent. The image scale is about 33 mm/pixel and the image measures about 55 m across. The image shows a mix of coarse and fine-grained material.
- Bottom right: the penultimate image, which was the last complete image taken and returned by Rosetta during its descent, from an altitude of 24.7±1.5 m.
- Bottom left: the final image, reconstructed after Rosetta's landing, was taken at an altitude of 19.5±1.5 m. The image has a scale of 2 mm/pixel and measures about 1 m across.
• June 8, 2017: The challenging detection, by ESA's Rosetta mission, of several isotopes of the noble gas xenon at Comet 67P/Churyumov-Gerasimenko has established the first quantitative link between comets and the atmosphere of Earth. The blend of xenon found at the comet closely resembles U-xenon, the primordial mixture that scientists believe was brought to Earth during the early stages of Solar System formation. These measurements suggest that comets contributed about one fifth the amount of xenon in Earth's ancient atmosphere. 111)
- Xenon – a colorless, odorless gas which makes up less than one billionth of the volume of Earth's atmosphere – might hold the key to answer a long-standing question about comets: did they contribute to the delivery of material to our planet when the Solar System was taking shape, some 4.6 billion years ago? And if so, by how much?
- The noble gas xenon is formed in a variety of stellar processes, from the late phases of low- and intermediate-mass stars to supernova explosions and even neutron star mergers. Each of these phenomena gives rise to different isotopes of the element. As a noble gas, xenon does not interact with other chemical species, and is therefore an important tracer of the material from which the Sun and planets originated, which in turns derives from earlier generations of stars.
- "Xenon is the heaviest stable noble gas and perhaps the most important because of its many isotopes that originate in different stellar processes: each one provides an additional piece of information about our cosmic origins," says Bernard Marty from CRPG-CNRS and Université de Lorraine, France. Bernard is the lead author of a paper reporting Rosetta's discovery of xenon at Comet 67P/C-G, which is published today in Science. 112)
- It is because of this special 'fingerprint' that scientists have been using xenon to investigate the composition of the early Solar System, which provides important clues to constrain its formation. Over the past decades, they sampled the relative abundances of its various isotopes at different locations: in the atmosphere of Earth and Mars, in meteorites deriving from asteroids, at Jupiter, and in the solar wind – the flow of charged particles streaming from the Sun.
Figure 82: The blend of isotopes of the noble gas xenon detected by ESA's Rosetta mission at Comet 67P/Churyumov-Gerasimenko, compared with the mixture of xenon measured in other regions of the Solar System. All abundances are normalized with respect to the abundance observed in the solar wind, the flow of charged particles streaming from the Sun (shown as a yellow line), image credit: Data from B. Marty et al., 2017 and references therein
- The blend of xenon present in the atmosphere of our planet contains a higher abundance of heavier isotopes with respect to the lighter ones; however, this is a result of lighter elements escaping more easily from Earth's gravitational pull and being lost to space in greater amounts. By correcting the atmospheric composition of xenon for this runaway effect, scientists in the 1970s calculated the composition of the primordial mixture of this noble gas, known as U-xenon, that was once present on Earth.
- This U-xenon contained a similar mix of light isotopes to that of asteroids and the solar wind, but included significantly smaller amounts of the heavier isotopes.
- "For these reasons, we have long suspected that xenon in the early atmosphere of Earth could have a different origin from the average blend of this noble gas found in the Solar System," says Bernard.
- One of the explanations is that Solar System xenon derives directly from the protosolar cloud, a mass of gas and dust that gave rise to the Sun and planets, while the xenon found in the Earth's atmosphere was delivered at a later stage by comets, which in turn might have formed from a different mix of material.
- With ESA's Rosetta mission visiting Comet 67P/Churyumov-Gerasimenko, an icy fossil of the early Solar System, scientists could finally gather the long-sought data to test this hypothesis.
- "Searching for xenon at the comet was one of the most crucial and challenging measurements we performed with Rosetta," says Kathrin Altwegg from the University of Bern, Switzerland, principal investigator of ROSINA, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, which was used for this study.
- Xenon is very diffuse in the comet's thin atmosphere, so the navigation team had to fly Rosetta very close – 5 km to 8 km from the surface of the nucleus – for a period of three weeks so that ROSINA could obtain a significant detection of all the relevant isotopes.
- Flying so close to the comet was extremely challenging because of the large amount of dust that was lifting off the surface at the time, which could confuse the star trackers that were used to orient the spacecraft.
- Eventually, the Rosetta team decided to perform this operation in the second half of May 2016. This period was chosen as a compromise so that enough time would have passed after the comet's perihelion, in August 2015, for the dust activity to be less intense, but not too much for the atmosphere to be excessively thin and the presence of xenon hard to detect.
- As a result of the observations, ROSINA identified seven isotopes of xenon, as well as several isotopes of another noble gas, krypton; these brought to three the inventory of noble gases found at Rosetta's comet, following the discovery of argon from measurements performed in late 2014.
- "These measurements required a long stretch of dedicated time solely for ROSINA, and it would have been very disappointing if we hadn't detected xenon at Comet 67P/C-G, so I'm really glad that we succeeded in detecting so many isotopes," adds Kathrin.
- Further analysis of the data revealed that the blend of xenon at Comet 67P/C-G, which contains larger amounts of light isotopes than heavy ones, is quite different from the average mixture found in the Solar System. A comparison with the on-board calibration sample confirmed that the xenon detected at the comet is also different from the current mix in the Earth's atmosphere.
- By contrast, the composition of xenon detected at the comet seems to be closer to the composition that scientists think was present in the early atmosphere of Earth.
- "This is a very exciting result because it is the first discovery of a candidate for the hypothesized U-xenon," explains Bernard.
- "There are some discrepancies between the two compositions, which indicate that the primordial xenon delivered to our planet could derive from a combination of impacting comets and asteroids."
- In particular, Bernard and his colleagues were able to establish the first quantitative link between comets and our planet's gaseous shroud: based on the Rosetta measurements at Comet 67P/C-G, 22 percent of the xenon once present in Earth's atmosphere could originate from comets – the rest being delivered by asteroids.
- This result is not in contradiction with the isotopic measurements of water at Rosetta's comet, which were significantly different to that found on Earth. In fact, given the trace amounts of xenon in Earth's atmosphere and the much larger amount of water in the oceans, comets could have contributed to atmospheric xenon without having a significant impact on the composition of water in the oceans.
- The contribution inferred from the xenon measurements, instead, agrees with the possibility that comets have been significant carriers of pre-biotic material – such as phosphorus and the amino acid glycine, which were also detected by Rosetta at the comet – that was crucial to the emergence of life on Earth.
- Finally, the difference between the blend of xenon found at the comet – which was incorporated in the nucleus at the time of its formation – and the xenon observed across the Solar System indicates that the protosolar cloud from which the Sun, planets, and small bodies were born was a rather inhomogeneous place in terms of its chemical composition.
- "This conclusion is in accord with previous measurements performed by Rosetta, including the unexpected detections of molecular oxygen (O2) and di-sulphur (S2), and the high deuterium-to-hydrogen ratio observed in the comet water," adds Kathrin.
- Additional evidence for the inhomogeneous nature of the protosolar cloud came also from anther study based on ROSINA observations, published in May in Astronomy & Astrophysics, which revealed that the mixture of silicon isotopes seen at the comet is different from what is measured elsewhere in the Solar System.
• March 21, 2017: Rosetta scientists have made the first compelling link between an outburst of dust and gas and the collapse of a prominent cliff, which also exposed the pristine, icy interior of the comet. 114) Growing fractures, collapsing cliffs, rolling boulders and moving material burying some features on the comet's surface while exhuming others are among the remarkable changes documented during Rosetta's mission. 115) 116) 117)
Figure 83: A 3D view of the Aswan cliff before and after part of it collapsed. The cliff was originally observed to have a 70 m-long, 1 m-wide fracture separating an overhanging block 12 m across from the main plateau. After the collapse, bright, pristine material is observed in the cliff wall, with new debris at the foot of the cliff (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; F. Scholten & F. Preusker)
- Sudden and short-lived outbursts were observed frequently during Rosetta's two-year mission at Comet 67P/Churyumov–Gerasimenko. Although their exact trigger has been much debated, the outbursts seem to point back to the collapse of weak, eroded surfaces, with the sudden exposure and heating of volatile material likely playing a role.
- In a study published today in Nature Astronomy, scientists make the first definitive link between an outburst and a crumbling cliff face, which is helping us to understand the driving forces behind such events. 118)
Figure 84: Comet cliff collapse: before and after (image credit: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0; ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Legend to Figure 84: Left: images of the 70 m-long, 1 m-wide fracture at the top of the 134 m-high Aswan cliff in the Seth region of Comet 67P/Churyumov–Gerasimenko (marked with arrow). The last image of the fracture still present was taken on 4 July 2015 (not shown here). Center: a broad plume of dust is imaged by Rosetta's navigation camera on 10 July 2015, which can be traced back to an area on the comet that encompasses the Seth region (the Aswan cliff is included within the marked rectangle). Right: two example images taken after the cliff collapse, showing the exposed material in the cliff face (top) and the new outline of the cliff top (bottom).
- The first close images of the comet taken in September 2014 revealed a 70 m-long, 1 m-wide fracture on the prominent cliff-edge subsequently named Aswan, in the Seth region of the comet, on its large lobe.
- Over the course of the following year as the comet drew ever closer to the Sun along its orbit, the rate at which its buried ices turned to vapor and dragged dust out into space increased along the way. Sporadic and brief, high-speed releases of dust and gas punctuated this background activity with outbursts.
- One such outburst was captured by Rosetta's navigation camera on 10 July 2015, which could be traced back to a portion of the comet's surface that encompassed the Seth region.
Figure 85: Evolution of a comet cliff collapse (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Legend to Figure 85: Sequence of images showing different views of the Aswan cliff collapse on Comet 67P/Churyumov–Gerasimenko. The first image shows the fracture long before it gave away on 10 July 2015. Images taken on 15 July and 26 December show the bright, pristine material exposed in the cliff collapse, which is thought to have occurred on 10 July. Although not obvious from these images, the brightness had faded by about 50% by the 26 December image, showing that much of the exposed water-ice had already sublimated by that time. The images from 2016 show different views of the new cliff top. By August 2016, much of the cliff face had returned to the average brightness of the comet. — Arrows are used to mark the fracture and the exposed water-ice, and to delineate the new cliff top outline.
- The next time the Aswan cliff was observed, five days later, a bright and sharp edge was spotted where the previously identified fracture had been, along with many new meter-sized boulders at the foot of the 134 m-high cliff. "The last time we saw the fracture intact was on 4 July, and in the absence of any other outburst events recorded in the following ten-day period, this is the most compelling evidence that we have that the observed outburst was directly linked to the collapse of the cliff," says Maurizio Pajola, the study leader.
- The event also provided a unique opportunity to study how the pristine water-ice otherwise buried tens of meters inside the comet evolved as the exposed material turned to vapor over the following months (Figure 86).
Figure 86: Comet cliff collapse in 3D. Anaglyph images of the Aswan cliff showing the overhang before (left) and after (right) it collapsed. The anaglyph images were prepared for evaluating the volume of overhang that detached in July 2015. Note the orientation between the two images is different (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; M. Pajola)
- Indeed, after the event, the exposed cliff face was calculated to be at least six times brighter than the overall average surface of the comet nucleus. By 26 December 2015 the brightness had faded by half, suggesting much of the water-ice had already vaporised by that time. — And by 6 August 2016, most of the new cliff face had faded back to the average, with only one large, brighter block remaining.
Figure 87: Fallen cliff debris. Color-coded plot showing the number and size distribution of boulders at the bottom of the Aswan cliff in the Seth region of Comet 67P/Churyumov–Gerasimenko before and after a large section collapsed on 10 July 2015. Significantly more smaller boulders are identified than larger pieces of debris (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Pajola et al. (2017)
- In addition, the team had a clear ‘before and after' look at how the crumbling material settled at the foot of the cliff. By counting the number of new boulders seen after its collapse, the team estimated that 99% of the fallen debris was distributed at the bottom of the cliff, while 1% was lost to space.
- This corresponds to around 10,000 tons of removed cliff material, with at least 100 tons that did not make it to the ground, consistent with estimates made for the volume of dust in the observed plume. Furthermore, the size range of the new debris, between 3 m and 10 m, is consistent with the distributions observed at the foot of several other cliffs identified on the comet.
- "We see a similar trend at the foot of other cliffs that we have not been so fortunate to have before and after images, so this is an important validation of cliff collapse as a producer of these debris fields," says Maurizio.
- But what actually led to the cliff suddenly collapsing at this particular moment?
Figure 88: Cliff collapse and comet activity (image credit: Based on J.-B. Vincent et al (2015)
Legend to Figure 88: Much of the comet's regular activity can be linked back to the steady erosion of cliff walls that are initially fractured by thermal or mechanical erosion. These fractures propagate into the underlying mixture of ice and dust. As the ices sublimate, the gases escape through the fractures, acting a bit like nozzles to focus the gas flows and picking up dust a long the way to create the distinct collimated jets observed in Rosetta's images. Continued cracking, heating and sublimation eventually leads to sudden collapse of the cliff wall – the likely source of more-transient outburst events. At the same time, the debris that falls to the foot of the cliff also exposes previously hidden material, contributing to the observed outflow.
- An earlier study suggested that both rapid daily changes in heating or longer-term seasonal changes can create thermal stresses that lead to fracturing and subsequent exposure of volatile materials, triggering a rapid outburst that can cause the weakened cliff to collapse.
- Even though the Aswan cliff region had been experiencing large temperature changes in the months before the collapse, interestingly, the collapse occurred at local night, ruling out a sudden extreme temperature change as the immediate trigger.
- Instead, both daily and seasonal temperature variations may have propagated fractures deeper into the subsurface than previously considered, predisposing it to the subsequent collapse.
- "If the fractures permeated volatile-rich layers, heat could have been transferred to these deeper layers, causing a loss of deeper ice," explains Maurizio. "The gas released by the vaporising material could further widen the fractures, leading to a cumulative effect that eventually led to the cliff collapse. Thanks to this particular event at Aswan, we think that the cumulative effect led by strong thermal gradients could be one of the most important weakening factors of the cliff structure."
- "Rosetta's images already suggested that cliff collapses are important in shaping cometary surfaces, but this particular event has provided the missing ‘before–after' link between such a collapse, the debris seen at the foot of the cliff, and the associated dust plume, supporting a general mechanism where comet outbursts can indeed be generated by collapsing material," says Matt Taylor, ESA's Rosetta project scientist.
• December 15, 2016: ESA's Rosetta completed its incredible mission on 30 September, collecting unprecedented images and data right until the moment of contact with the comet's surface. Rosetta's signal disappeared from screens at ESA's mission control at 11:19:37 GMT, confirming that the spacecraft had arrived on the surface of Comet 67P/Churyumov–Gerasimenko and switched off some 40 minutes earlier and 720 million kilometers from Earth. 119)
- One of the final pieces of information received from Rosetta was sent by its navigation star trackers: a report of a ‘large object' in the field of view – the comet horizon.
Figure 89: Imaging ‘footprints' of Rosetta's OSIRIS camera during the descent to the comet's surface. A primary focus was the pit named Deir el-Medina, as indicated by the number of footprints indicated in blue. The trail of orange and red squares reflect the change in pointing of the camera towards the impact site, subsequently named Sais. The final image was acquired at about 20 m above the surface, and the touchdown point was only 33 m from the center of the predicted landing ellipse (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
- Reconstruction of the final descent showed that the spacecraft gently struck the surface only 33 m from the target point. The accuracy once again highlighted the excellent work of the flight dynamics specialists who supported the entire mission. The spot, just inside an ancient pit in the Ma'at region on the comet's ‘head', was named Sais, after a town where the Rosetta Stone was originally located.
- Numerous images were taken of the neighboring pit, capturing incredible details of its layered walls that will be used to help decipher the comet's geological history.
- The final image was acquired about 20 m above the impact point. In addition, a number of Rosetta's dust, gas and plasma analysis instruments collected data.
- The pressure of the gas outflow from the comet was seen to rise as the surface neared. Scans revealed temperatures between about –190ºC and –110ºC down to a few centimeters below the surface. The variation was most likely due to shadows and local topography as Rosetta flew across the surface.
- A last measurement of water vapor emission was made on 27 September, estimating the comet was emitting the equivalent of two tablespoons of water per second. During its most active period in August 2015, estimates were in the region of two bathtubs' worth of water every second.
Figure 90: Rosetta's last image of Comet 67P/Churyumov-Gerasimenko, taken with the OSIRIS wide-angle camera shortly before impact, at an estimated altitude of about 20 m above the surface (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Legend to Figure 90: The initially reported 51 m was based on the predicted impact time. Now that this has been confirmed, and following additional information and timeline reconstruction, the estimated distance is now thought to be around 20 m, and analysis is ongoing. The image scale is about 2 mm/pixel and the image measures about 96 cm across.
Figure 91: Comet landing sites in context: Rosetta's planned impact point in Ma'at shown in context with Philae's first and final touchdown sites. All three sites are on the smaller of Comet 67P/Churyumov–Gerasimenko's two lobes (image credit: CIVA: ESA/Rosetta/Philae/CIVA; NAVCAM: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0; OSIRIS: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; ROLIS: ESA/Rosetta/Philae/ROLIS/DLR) 120)
Legend to Figure 91: The insets show close-up details of the three sites. Philae's first touchdown in Agilkia was captured by the lander's descent camera ROLIS; the image shown here was taken from a height of just 9 m above the surface on 12 November 2014, and has a resolution of 0.95 cm/pixel. The view at Philae's final touchdown site, known as Abydos, was taken by the lander's CIVA camera on 13 November 2014; the image shown here is a two-image mosaic, and includes one of the lander's feet.
- The first indications from spectral readings show there to be no significant differences in surface composition at the high resolutions obtained all the way down, and there was no obvious indication of small icy patches near the landing site. The measurements also suggest an increase in very small dust grains – possibly around a millionth of a millimeter – close to the surface.
- The last observation of the gas coma surrounding the comet was made the day before the final descent. Carbon dioxide was still being outgassed, at a greater distance from the Sun than when the comet was approaching it. Stable solar wind conditions reigned during the final measurements of the solar wind and interplanetary magnetic field, providing ‘quiet' background values that will be important for calibration. Decreasing comet plasma densities were observed from about 2 km above the surface, with no obvious detection of local outgassing from the Ma'at pits.
- Magnetic field measurements down to an estimated 11 m above the surface confirmed the previous observations of the comet as a non-magnetic body.
- No large dust particles were collected during the descent, in itself an interesting result. First impressions are that the observed water vapor production was too low to lift dust grains above a detectable size from the surface.
- "It's great to have these first insights from Rosetta's last set of data," says Matt Taylor, ESA's Rosetta Project Scientist. "Operations have been completed for over two months now, and the instrument teams are very much focused on analyzing their huge datasets collected during Rosetta's two-plus years at the comet.
• November 17, 2016: As Rosetta's comet approached its most active period last year, the spacecraft spotted carbon dioxide ice – never before seen on a comet – followed by the emergence of two unusually large patches of water ice. 121) 122) 123)
- The carbon dioxide ice layer covered an area comparable to the size of a football pitch, while the two water ice patches were each larger than an Olympic swimming pool and much larger than any signs of water ice previously spotted at the comet.- The three icy layers were all found in the same region, on the comet's southern hemisphere.
- A combination of the complex shape of the comet, its elongated path around the Sun and the substantial tilt of its spin, seasons are spread unequally between the two hemispheres of the double-lobed Comet 67P/Churyumov-Gerasimenko.
- When Rosetta arrived in August 2014, the northern hemisphere was still undergoing its 5.5 year summer, while the southern hemisphere was in winter and much of it was shrouded in darkness. — However, shortly before the comet's closest approach to the Sun in August 2015, the seasons changed and the southern hemisphere experienced a brief but intense summer, exposing this region to sunlight again.
- In the first half of 2015, as the comet steadily became more active, Rosetta observed water vapour and other gases pouring out of the nucleus, lifting its dusty cover and revealing some of the comet's icy secrets. In particular, on two occasions in late March 2015, Rosetta's visible, infrared and thermal imaging spectrometer, VIRTIS, found a very large patch of carbon dioxide ice in the Anhur region, in the comet's southern hemisphere.
- This is the first detection of solid carbon dioxide on any comet, although it is not uncommon in the Solar System – it is abundant in the polar caps of Mars, for example. "We know comets contain carbon dioxide, which is one of the most abundant species in cometary atmospheres after water, but it's extremely difficult to observe it in solid form on the surface," explains Gianrico Filacchione from Italy's INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali, who led the study.
- In the comet environment, carbon dioxide freezes at -193°C, much below the temperature where water turns into ice. Above this temperature, it changes directly from a solid to a gas, hampering its detection in ice form on the surface. By contrast, water ice has been found at various comets, and Rosetta detected plenty of small patches on several regions. "We hoped to find signs of carbon dioxide ice and had been looking for it for quite a while, but it was definitely a surprise when we finally detected its unmistakable signature," adds Gianrico.
- The patch, consisting of a few percent of carbon dioxide ice combined with a darker blend of dust and organic material, was observed on two consecutive days in March. This was a lucky catch: when the team looked at that region again around three weeks later, it was gone.
- Assuming that all of the ice had turned into gas, the scientists estimated that the 80 m x 60 m patch contained about 57 kg of carbon dioxide, corresponding to a 9 cm-thick layer. Its presence on the surface is likely an isolated rare case, with the majority of carbon dioxide ice being confined to deeper layers of the nucleus.
- Gianrico and his collaborators believe the icy patch dates back a few years, when the comet was still in the cold reaches of the outer Solar System and the southern hemisphere was experiencing its long winter. At that time, some of the carbon dioxide still outgassing from the interior of the nucleus condensed on the surface, where it remained frozen for a very long while, and vaporised only as the local temperature finally rose again in April 2015.
- This reveals a seasonal cycle of carbon dioxide ice, which unfolds over the comet's 6.5 year orbit, as opposed to the daily cycle of water ice, also spotted by VIRTIS shortly after Rosetta's arrival.
Figure 92: First detection of carbon dioxide at a comet (image credit: data: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; Reprinted with permission from G. Filacchione et al., Science 10.1126/science.aag3161 (2016); context image: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0)
- Interestingly, shortly after the carbon dioxide ice had disappeared, Rosetta's OSIRIS narrow-angle camera detected two unusually large patches of water ice in the same area, between the southern regions of Anhur and Bes (Figure 93). "We had already seen many meter-sized patches of exposed water ice in various regions of the comet, but the new detections are much larger, spanning some 30 m x 40 m each, and they persisted for about 10 days before they completely disappeared," says Sonia Fornasier from LESIA–Observatoire de Paris and Université Paris Diderot, France, lead scientist of the study focusing on seasonal and daily surface color variations.
- These ice-rich areas appear as very bright portions of the comet surface reflecting light that is bluer in color compared with the redder surroundings. Scientists have experimented with mixtures of dust and water ice to show that, as the concentration of ice in them increases, the reflected light becomes gradually bluer in color, until reaching a point where equal amounts of light are reflected in all colors.
- The two newly detected patches contain 20–30% of water ice mixed with darker material, forming a layer up to 30 cm thick of solid ice. One of them was likely lurking underneath the carbon dioxide ice sheet revealed by VIRTIS about a month before.
Figure 93: Large patches of water ice found on comet surface (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Reprinted with permission from S. Fornasier et al., Science 10.1126/science.aag2671 (2016), Ref. 123)
• September 30, 2016: ESA's historic Rosetta mission has concluded as planned, with the controlled impact onto the comet it had been investigating for more than two years. Confirmation of the end of the mission arrived at ESA's control center in Darmstadt, Germany at 11:19 UTC (13:19 CEST) with the loss of Rosetta's signal upon impact into 67P/Churyumov-Gerasimenko, 718 million km from Earth. Controlled hard-landing has become a common way to end the missions of planetary probes. But while most have been very high-velocity impacts, Rosetta's touchdown was made at a sedate walking pace of 2 km/h. 124) 125) 126)
- Rosetta carried out its final maneuver last night at 20:50 UTC (22:50 CEST), setting it on a collision course with the comet from an altitude of about 19 km. Rosetta had targeted a region on the small lobe of Comet 67P/Churyumov–Gerasimenko, close to a region of active pits in the Ma'at region.
- The descent gave Rosetta the opportunity to study the comet's gas, dust and plasma environment very close to its surface, as well as take very high-resolution images. - Pits are of particular interest because they play an important role in the comet's activity. They also provide a unique window into its internal building blocks.
- The information collected on the descent to this fascinating region was returned to Earth before the impact. It is now no longer possible to communicate with the spacecraft.
- "Rosetta has entered the history books once again," says Johann-Dietrich Wörner, ESA's Director General. "Today we celebrate the success of a game-changing mission, one that has surpassed all our dreams and expectations, and one that continues ESA's legacy of 'firsts' at comets."
- "Thanks to a huge international, decades-long endeavor, we have achieved our mission to take a world-class science laboratory to a comet to study its evolution over time, something that no other comet-chasing mission has attempted," notes Alvaro Giménez, ESA's Director of Science. "Rosetta was on the drawing board even before ESA's first deep-space mission, Giotto, had taken the first image of a comet nucleus as it flew past Halley in 1986. "The mission has spanned entire careers, and the data returned will keep generations of scientist busy for decades to come."
- "As well as being a scientific and technical triumph, the amazing journey of Rosetta and its lander Philae also captured the world's imagination, engaging new audiences far beyond the science community. It has been exciting to have everyone along for the ride," adds Mark McCaughrean, ESA's senior science advisor.
- Many surprising discoveries have already been made during the mission, not least the curious shape of the comet that became apparent during Rosetta's approach in July and August 2014. Scientists now believe that the comet's two lobes formed independently, joining in a low-speed collision in the early days of the Solar System. Long-term monitoring has also shown just how important the comet's shape is in influencing its seasons, in moving dust across its surface, and in explaining the variations measured in the density and composition of the coma, the comet's ‘atmosphere'.
- Some of the most unexpected and important results are linked to the gases streaming from the comet's nucleus, including the discovery of molecular oxygen and nitrogen, and water with a different ‘flavor' to that in Earth's oceans.- Together, these results point to the comet being born in a very cold region of the protoplanetary nebula when the Solar System was still forming more than 4.5 billion years ago.
- While it seems that the impact of comets like Rosetta's may not have delivered as much of Earth's water as previously thought, another much anticipated question was whether they could have brought ingredients regarded as crucial for the origin of life. - Rosetta did not disappoint, detecting the amino acid glycine, which is commonly found in proteins, and phosphorus, a key component of DNA and cell membranes. Numerous organic compounds were also detected by Rosetta from orbit, and also by Philae in situ on the surface.
- Overall, the results delivered by Rosetta so far paint comets as ancient leftovers of early Solar System formation, rather than fragments of collisions between larger bodies later on, giving an unparalleled insight into what the building blocks of the planets may have looked like 4.6 billion years ago.
- "Just as the Rosetta Stone after which this mission was named was pivotal in understanding ancient language and history, the vast treasure trove of Rosetta spacecraft data is changing our view on how comets and the Solar System formed," says project scientist Matt Taylor. "Inevitably, we now have new mysteries to solve. The comet hasn't given up all of its secrets yet, and there are sure to be many surprises hidden in this incredible archive. So don't go anywhere yet – we're only just beginning."
Figure 94: Rosetta's OSIRIS narrow-angle camera captured this image of Comet 67P/Churyumov-Gerasimenko at 06:53 UTC from an altitude of about 8.9 km during the spacecraft's final descent on 30 September. The image scale is about 17 cm/pixel and the image measures about 350 m across (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Figure 95: Headed for the abyss? This photo was made from 1.2 km high just a few minutes before impact. The scene measures just 33 m wide (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
• September 27, 2016: Over the past two years, Rosetta has kept a close eye on many properties of Comet 67P/Churyumov-Gerasimenko, tracking how these changed along the comet's orbit. A very crucial aspect concerns how much water vapor a comet releases into space, and how the water production rate varies at different distances from the Sun. For the first time, Rosetta enabled scientists to monitor this quantity and its evolution in situ over two years. 127)
- In a new study led by Kenneth C. Hansen of the University of Michigan, Ann Arbor, MI, USA, measurements of water production rate based on data from ROSINA, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, are compared with water measurements from other Rosetta instruments. 128)
- The combination of all instruments shows an overall increase of the production of water, from a few tens of thousands of kg per day when Rosetta first reached the comet, in August 2014, to almost 100 000 000 kg per day around perihelion, the closest point to the Sun along the comet's orbit, in August 2015. In addition, ROSINA data show that the peak in water production is followed by a rather steep decrease in the months following perihelion.
- "We were pleasantly surprised to find such a good agreement between the data collected by all the various instruments in this unprecedented study of the water production rate's evolution for a Jupiter-family comet," says Hansen. The scientists analyzed almost two years' worth of data from ROSINA, which detects neutral water molecules with its DFMS (Double-Focussing Mass Spectrometer). "This is by no means trivial: ROSINA performs measurements locally, at specific points around the comet, and we need a model to extend them to the entire atmosphere," adds Hansen.
Figure 96: The water production rate measured at Comet 67P/C-G as a function of the comet's distance from the Sun (in astronomical units, AU). The measurements are from ROSINA-DFMS (blue diamonds); MIRO (yellow circles); VIRTIS-H (solid green triangles); VIRTIS-M (unfilled green triangles); RPC-ICA (red triangles). The dust production rate, estimated from ground-based observations, is indicated in tan crosses. The data span the period between June 2014 and May 2016 (image adapted from Ref. 128)
- The simplest model would be a spherical distribution of the outgassing centered around the nucleus but, given the complex shape and season cycle of Comet 67P/C-G, this would be a very crude approximation. For this reason, the ROSINA team developed a series of numerical simulations to accurately describe the comet's production of water, which are presented in a separate study led by Nicolas Fougere also of the University of Michigan. 129)
- From these simulations, which showed that the water production rate at a comet like 67P/C-G is highly inhomogeneous, Hansen and his colleagues derived an empirical model, which they then used to transform the local ROSINA measurements into estimates of the overall water production rate.
- The results revealed that, during the first several months of observations, when the comet was at distances between 3.5 and 1.7 astronomical units (au) from the Sun, water was predominantly produced in the comet's northern hemisphere.
Figure 97: The water production rate predicted by simulations as Comet 67P/C-G approached the Sun, from August 2014 (left) to May 2015 (right), before the equinox that marked the end of the northern summer. Images adapted from Hansen et al. (2016); animations courtesy of K.C. Hansen.
- Then, in May 2015, the equinox marked the end of the 5.5-year long northern summer and the beginning of the short and intense southern summer. At that time, the comet was about 1.7 au from the Sun, and scientists expected that the peak of water production would drift slowly from the northern to the southern hemisphere; instead, this transition happened more abruptly than predicted. This was likely due to the complex shape of the nucleus, which causes highly variable illumination conditions including self-shadowing effects.
- As expected, the production of water peaked between the end of August and early September 2015, about three weeks after the comet's perihelion, which took place on 13 August, 1.24 au from the Sun. The data hint at possible variations in the water production rate at this epoch: these might be due to the spacecraft's motion relative to the comet, but could also be an indication of actual changes to the outgassing dynamics, and will be subject of future in-depth investigation.
Figure 98: The water production rate predicted by simulations after the equinox of Comet 67P/C-G, which marked the beginning of the southern summer, and covering several weeks around the comet's perihelion. Images adapted from Hansen et al. (2016); animations courtesy of K.C. Hansen
- In addition to the ROSINA measurements, Hansen and his colleagues collated a series of previously published measurements of the water production rate at 67P/C-G. These include observations performed with the Microwave Instrument for the Rosetta Orbiter (MIRO) shortly before and after Rosetta had reached the comet, data from the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) obtained between November 2014 and January 2015, and measurements from the Ion Composition Analyzer, part of the Rosetta Plasma Consortium (RPC) suite of instruments, obtained between October 2014 and April 2015.
- RPC-ICA does not detect water directly, but rather measures the ratio of differently ionized Helium ions; since He+ ions arise mainly from collisions between alpha particles (He2+) from the solar wind and neutral molecules, such as water, found in the comet's atmosphere, this ratio can be used to estimate the amount of water produced at the comet.
- Hansen and his collaborators have found some small discrepancies between the various data sets: for example, the measurements from ROSINA yield systematically higher values than those from VIRTIS. One possible reason for this is the different nature of the two experiments: ROSINA samples the gas in the coma at the spacecraft's position, while VIRTIS tends to observe closer to the nucleus, where the water production activity is potentially more confined than it is further out in the coma. The difference in measurements techniques and the discrepancy could potentially indicate an extended source of water in the coma itself, for example icy grains that are lifted into the coma and turn into gas a few kilometers above the surface.
- Another difference was found between the MIRO measurements, which indicate a rising trend in the water production rate from June to September 2014, and the first months of ROSINA data, starting in August, pointing to an almost constant rate in the same period. "This could be explained if a sudden surge in the water production happened around the time of the first MIRO measurement, a few weeks before Rosetta's rendezvous with 67P/C-G, and the beginning of ROSINA observations," says Hansen.
• September 23, 2016: Brief but powerful outbursts seen from Comet 67P/Churyumov–Gerasimenko during its most active period last year have been traced back to their origins on the surface. In the three months centered around the comet's closest approach to the Sun, on 13 August 2015, Rosetta's cameras captured 34 outbursts. These violent events were over and above regular jets and flows of material seen streaming from the comet's nucleus. The latter switch on and off with clockwork repeatability from one comet rotation to the next, synchronized with the rise and fall of the Sun's illumination. 130) 131)
- By contrast, outbursts are much brighter than the usual jets – sudden, brief, high-speed releases of dust. They are typically seen only in a single image, indicating that they have a lifetime shorter than interval between images – typically 5–30 minutes. A typical outburst is thought to release 60–260 tons of material in those few minutes.
- On average, the outbursts around the closest approach to the Sun occurred once every 30 hours – about 2.4 comet rotations. Based on the appearance of the dust flow, they can be divided into three categories. One type is associated with a long, narrow jet extending far from the nucleus, while the second involves a broad, wide base that expands more laterally. The third category is a complex hybrid of the other two.
- "As any given outburst is short-lived and only captured in one image, we can't tell whether it was imaged shortly after the outburst started, or later in the process," notes Jean-Baptiste Vincent, lead author of the paper published in MNRAS (Monthly Notices of the Royal Astronomical Society). "As a result, we can't tell if these three types of plume ‘shapes' correspond to different mechanisms, or just different stages of a single process. - But if just one process is involved, then the logical evolutionary sequence is that an initially long narrow jet with dust is ejected at high speed, most likely from a confined space. -Then, as the local surface around the exit point is modified, a larger fraction of fresh material is exposed, broadening the plume ‘base'. - Finally, when the source region has been altered so much as not to be able to support the narrow jet anymore, only a broad plume survives."
- The OSIRIS cameras on board ESA's Rosetta spacecraft have monitored the activity of comet 67P-Churyumov-Gerasimenko (67P) across varying heliocentric distances (4 AU to 1.24 AU) and different seasons on the nucleus (sub solar latitude between +45º and -55 º). One of the striking discoveries of Rosetta has been the clockwork repeatability of jets from one rotation to the next. Jets are very dynamic by nature, depending on the complex hydrodynamics of the gas and dust streams interacting with the local topography, and controlled by local thermal conditions. They grow and fade with the solar illumination as the nucleus rotates, but the same exact features can be observed from one rotation to the next. Figure 99 shows an example of this phenomenon. This, of course, put constraints on the thermophysics and volatile content of active areas, which need to ensure the sustainability and repeatability of the jets we observed.
Figure 99: Example of two images acquired on 2015-08-09T12.09.49 (left) and 2015-08-10T00.23.00 (right), almost one rotation apart (Rotation period - images separation = 5min33s). Both images contrast is stretched to the same level (5% of the same maximum brightness value). Field of view 1x1 degree, distance = 305 km, resolution = 5.7 m/px (image credit: ESA/Rosetta/NAVCAM - CC BYSA IGO 3.0)
- In the study, monitoring data acquired by the OSIRIS Narrow Angle and Wide Angle Cameras (NAC & WAC), as well as Rosetta's navigation camera (NAVCAM) were used to increase the temporal coverage. Around perihelion, OSIRIS monitoring campaigns were run on a weekly basis, with a set of images acquired every 1/2 h for slightly longer than the current nucleus rotation period (12h18m10s at perihelion). After noticing the first outbursts in July 2015, the cadence of images was increased in each observation, and the time was reduced between monitoring campaigns to a few days. In addition to the OSIRIS data, transient events in the navigation images were also looked into, acquired about every 4 hours during the whole mission.
To distinguish between outbursts and other short lived features, the following definition was established: An outburst is identified by a sudden brightness increase in the coma, associated to a release of gas and dust over a duration very short with respect to the rotation period of the nucleus. Typically detected in one image only, depending on the observing cadence. The dust plume is typically one order of magnitude brighter than the usual jets. Plume morphology as a criterion was not imposed.
Following this definition, 34 events were identified in the data set, listed in a Table. Among them, 26 were detected with OSIRIS NAC, 3 by OSIRIS WAC, and 5 by the NAVCAM. A visual catalog of the brightest evens is provided in Figure 100.
Figure 100: Mosaic of the brightest OSIRIS NAC (white) and NAVCAM (red) outbursts detected by Rosetta from July to September 2015 (image credit: ESA/Rosetta/NAVCAM - CC BYSA IGO 3.0)
- Figure 101 shows all outburst sources projected on a topographic map of 67P, and on a morphological map displaying the regions boundaries. All sources but one are located in the southern hemisphere, between 0 and -50º of latitude, i.e. around the sub solar latitude for this period (it varied from -30 to -55º). This is consistent with previous observations showing that active sources in general migrate with the Sun. Outburst sources are not evenly distributed along this latitude. Some clustering in three main areas were observed: (1) The Anhur-Aker boundary (big lobe), (2) the Anuket-Sobek boundary (big lobe), and (3) the Wosret-Maftet boundary (small lobe). These areas are characterized by steep scarps, cliffs, and pits, which contrast with the overall flatter morphology of the Southern hemisphere. It is interesting to note that beyond those three areas, it seems like all outbursts sources are located close to morphological boundaries, i.e. areas where we observe discontinuities in the local terrain, either textural or topographic. This seems to indicate a link between morphology and outbursts, although it is not clear which one influences the other.
Figure 101: Maps of all summer outbursts detected by the OSIRIS cameras (blue dots) and Rosetta's NAVCAM (red dots). The top panel plots the sources over a topographic maps in which the gray shading represents the local gravitational slope (white=flat, black=vertical wall). Dotted ellipses represent the estimated uncertainty for the few outbursts whose source was not observed directly (image credit: ESA/Rosetta/NAVCAM - CC BYSA IGO 3.0)
Legend to Figure 101: Note that this map is a 2D representation of a bi-lobate, strongly concave object, and therefore presents significant distortions. To guide the reader, white dashed lines of the boundary of the two lobes are indicated: the map is centered on the small lobe, the big lobe covers the left-right-bottom edges of the map, and the contact area between the two lobes covers mainly the top of the map (regions Hapi, Neith, Sobek). The 3 main clusters of outbursts sources are located around longitudes 60º (big lobe), 300º (southern neck), and 315º (small lobe).
• September 9, 2016: Squeezing out unique scientific observations until the very end, Rosetta's thrilling mission will culminate with a descent on 30 September towards a region of active pits on the comet's ‘head'. The region, known as Ma'at, lies on the smaller of the two lobes of Comet 67P/Churyumov–Gerasimenko. It is home to several active pits more than 100 m in diameter and 50–60 m in depth – where a number of the comet's dust jets originate. 132) 133)
- The walls of the pits also exhibit intriguing meter-sized lumpy structures called ‘goosebumps', which scientists believe could be the signatures of early ‘cometesimals' that assembled to create the comet in the early phases of Solar System formation.
- Rosetta will get its closest look yet at these fascinating structures on 30 September: the spacecraft will target a point adjacent to a 130 m-wide, well-defined pit that the mission team has informally named Deir el-Medina, after a structure with a similar appearance in an ancient Egyptian town of the same name.
- Like the archaeological artefacts found inside the Egyptian pit that tell historians about life in that town, the comet's pit contains clues to the geological history of the region. Rosetta will target a point very close to Deir el-Medina, within an ellipse about 700 x 500 m.
- Since 9 August, Rosetta has been flying elliptical orbits that bring it progressively closer to the comet – on its closest flyby, it may come within 1 km of the surface, closer than ever before.
- "Although we've been flying Rosetta around the comet for two years now, keeping it operating safely for the final weeks of the mission in the unpredictable environment of this comet and so far from the Sun and Earth, will be our biggest challenge yet," says Sylvain Lodiot, ESA's spacecraft operations manager. "We are already feeling the difference in gravitational pull of the comet as we fly closer and closer: it is increasing the spacecraft's orbital period, which has to be corrected by small maneuvers. But this is why we have these flyovers, stepping down in small increments to be robust against these issues when we make the final approach."
- The final flyover will be complete on 24 September. Then a short series of maneuvers needed to line Rosetta up with the target impact site will be executed over the following days as it transfers from flying elliptical orbits around the comet onto a trajectory that will eventually take it to the comet's surface on 30 September.
- The collision maneuver will take place in the evening of 29 September, initiating the descent from an altitude of about 20 km. Rosetta will essentially free-fall slowly towards the comet in order to maximize the number of scientific measurements that can be collected and returned to Earth before its impact.
- A number of Rosetta's scientific instruments will collect data during the descent, providing unique images and other data on the gas, dust and plasma very close to the comet. The exact complement of instruments and their operational timeline remains to be fixed, because it depends on constraints of the final planned trajectory and the data rate available on the day.
Figure 102: Rosetta's planned impact site (image credit: ESA)
Figure 103: Planned maneuvers of Rosetta during September for final impact on Comet 67P/Churyumov-Gerasimenko (image credit: ESA)
• September 7, 2016: Rosetta's dust-analyzing COSIMA (COmetary Secondary Ion Mass Analyzer) instrument has made the first unambiguous detection of solid organic matter in the dust particles ejected by Comet 67P/Churyumov-Gerasimenko, in the form of complex carbon-bearing molecules. 134) 135)
- The optical images (Figure 104) of two of the dust grains collected and analyzed by COSIMA, named Kenneth and Juliette, which show the signature of carbon-based organics. They were collected in May and October 2015, respectively.
Figure 104: COSIMA images of Comet 67P/C-G dust particles Kenneth and Juliette (image credit: ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S/ Fray et al. (2016))
• September 5, 2016: Less than a month before the end of the mission, Rosetta's high-resolution camera has revealed the Philae lander wedged into a dark crack on Comet 67P/Churyumov–Gerasimenko. 136) 137)
Figure 105: The images were taken on 2 September by the OSIRIS narrow-angle camera as the orbiter came within 2.7 km of the surface and clearly show the main body of the lander, along with two of its three legs .The images also provide proof of Philae's orientation, making it clear why establishing communications was so difficult following its landing on 12 November 2014. (image credit: Main image and lander inset: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; context: ESA/Rosetta/ NavCam – CC BY-SA IGO 3.0)
- "With only a month left of the Rosetta mission, we are so happy to have finally imaged Philae, and to see it in such amazing detail," says Cecilia Tubiana of the OSIRIS camera team, the first person to see the images when they were downlinked from Rosetta yesterday.
- "After months of work, with the focus and the evidence pointing more and more to this lander candidate, I'm very excited and thrilled that we finally have this all-important picture of Philae sitting in Abydos," says ESA's Laurence O'Rourke, who has been coordinating the search efforts over the last months at ESA, with the OSIRIS and Lander Science Operations and Navigation Center (SONC, CNES) teams.
- Philae was last seen when it first touched down at Agilkia, bounced and then flew for another two hours before ending up at a location later named Abydos, on the comet's smaller lobe. After three days, Philae's primary battery was exhausted and the lander went into hibernation, only to wake up again and communicate briefly with Rosetta in June and July 2015 as the comet came closer to the Sun and more power was available.
- However, until today, the precise location was not known. Radio ranging data tied its location down to an area spanning a few tens of meters, but a number of potential candidate objects identified in relatively low-resolution images taken from larger distances could not be analyzed in detail until recently.
- While most candidates could be discarded from analysis of the imagery and other techniques, evidence continued to build towards one particular target, which is now confirmed in images taken unprecedentedly close to the surface of the comet.
- At 2.7 km, the resolution of the OSIRIS narrow-angle camera is about 5 cm/pixel, sufficient to reveal characteristic features of Philae's 1 m-sized body and its legs, as seen in these definitive pictures.
- "This remarkable discovery comes at the end of a long, painstaking search," says Patrick Martin, ESA's Rosetta Mission Manager. "We were beginning to think that Philae would remain lost forever. It is incredible we have captured this at the final hour."
- "Now that the lander search is finished we feel ready for Rosetta's landing, and look forward to capturing even closer images of Rosetta's touchdown site," adds Holger Sierks, principal investigator of the OSIRIS camera.
Figure 106: Close-up image of Philae (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
• August 25, 2016: In unprecedented observations made earlier this year, Rosetta unexpectedly captured a dramatic comet outburst that may have been triggered by a landslide. Nine of Rosetta's instruments, including its cameras, dust collectors, and gas and plasma analyzers, were monitoring the comet from about 35 km in a coordinated planned sequence when the outburst happened on 19 February, 2016. 138) 139)
Figure 107: Outburst of Comet 67P/Churyumov-Gerasimenko on Feb. 19, 2016 observed by 9 instruments of the Rosetta Spacecraft (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
- "Over the last year, Rosetta has shown that although activity can be prolonged, when it comes to outbursts, the timing is highly unpredictable, so catching an event like this was pure luck," says Matt Taylor, ESA's Rosetta Project Scientist. "By happy coincidence, we were pointing the majority of instruments at the comet at this time, and having these simultaneous measurements provides us with the most complete set of data on an outburst ever collected."
- The data were sent to Earth only a few days after the outburst, but subsequent analysis has allowed a clear chain of events to be reconstructed, as described in a paper led by Eberhard Grün of the Max-Planck-Institute for Nuclear Physics, Heidelberg, accepted for publication in Monthly Notices of the Royal Astronomical Society.
- A strong brightening of the comet's dusty coma was seen by the OSIRIS wide-angle camera at 09:40 UTC, developing in a region of the comet that was initially in shadow.
- Over the next two hours, Rosetta recorded outburst signatures that exceeded background levels in some instruments by factors of up to a hundred. For example, between about 10:00–11:00 UTC, ALICE saw the ultraviolet brightness of the sunlight reflected by the nucleus and the emitted dust increase by a factor of six, while ROSINA and RPC detected a significant increase in gas and plasma, respectively, around the spacecraft, by a factor of 1.5–2.5. In addition, MIRO recorded a 30°C rise in temperature of the surrounding gas.
- Shortly after, Rosetta was blasted by dust: GIADA recorded a maximum hit count at around 11:15 UTC. Almost 200 particles were detected in the following three hours, compared with a typical rate of 3–10 collected on other days in the same month.
- At the same time, OSIRIS narrow-angle camera images began registering dust grains emitted during the blast. Between 11:10 UTC and 11:40 UTC, a transition occurred from grains that were distant or slow enough to appear as points in the images, to those either close or fast enough to be captured as trails during the exposures.
- In addition, the star trackers, which are used to navigate and help control Rosetta's attitude, measured an increase in light scattered from dust particles as a result of the outburst. - The star trackers are mounted at 90° to the side of the spacecraft that hosts the majority of science instruments, so they offered a unique insight into the 3D structure and evolution of the outburst.
Figure 108: Evolution of a comet outburst (credit of image: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; all data from Grün et al. (2016))
- By examining all of the available data, scientists believe they have identified the source of the outburst. "From Rosetta's observations, we believe the outburst originated from a steep slope on the comet's large lobe, in the Atum region," says Eberhard.
• July 28, 2016: Detailed analysis of data collected by Rosetta show that comets are the ancient leftovers of early Solar System formation, and not younger fragments resulting from subsequent collisions between other, larger bodies. — Understanding how and when objects like Comet 67P/Churyumov-Gerasimenko took shape is of utmost importance in determining how exactly they can be used to interpret the formation and early evolution of our Solar System (Figure 109). 140)
- A new study addressing this question led by Björn Davidsson of the Jet Propulsion Laboratory, California Institute of Technology in Pasadena (USA), has been published in Astronomy & Astrophysics. 141)
- If comets are primordial, then they could help reveal the properties of the solar nebula from which the Sun, planets and small bodies condensed 4.6 billion years ago, and the processes that transformed our planetary system into the architecture we see today.
- The alternative hypothesis is that they are younger fragments resulting from collisions between older 'parent' bodies such as icy trans-Neptunian objects (TNOs). They would then provide insight into the interior of such larger bodies, the collisions that disrupted them, and the process of building new bodies from the remains of older ones.
- "Either way, comets have been witness to important Solar System evolution events, and this is why we have made these detailed measurements with Rosetta – along with observations of other comets – to find out which scenario is more likely," says Matt Taylor, ESA's Rosetta project scientist.
- During its two-year sojourn at Comet 67P/Churyumov-Gerasimenko, Rosetta has revealed a picture of the comet as a low-density, high-porosity, double-lobed body with extensive layering, suggesting that the lobes accumulated material over time before they merged.
- The unusually high porosity of the interior of the nucleus provides the first indication that this growth cannot have been via violent collisions, as these would have compacted the fragile material. Structures and features on different size scales observed by Rosetta's cameras provide further information on how this growth may have taken place.
- Earlier work showed that the head and body were originally separate objects, but the collision that merged them must have been at low speed in order not to destroy both of them. The fact that both parts have similar layering also tells us that they must have undergone similar evolutionary histories and that survival rates against catastrophic collision must have been high for a significant period of time.
- Merging events may also have happened on smaller scales. For example, three spherical 'caps' have been identified in the Bastet region on the small comet lobe, and suggestions are that they are remnants of smaller cometesimals that are still partially preserved today.
- At even smaller scales of just a few meters across, there are the so-called 'goosebumps' and 'clod' features, rough textures observed in numerous pits and exposed cliff walls in various locations on the comet.
- While it is possible that this morphology might arise from fracturing alone, it is actually thought to represent an intrinsic 'lumpiness' of the comet's constituents. That is, these 'goosebumps' could be showing the typical size of the smallest cometesimals that accumulated and merged to build up the comet, made visible again today through erosion due to sunlight.
- According to theory, the speeds at which cometesimals collide and merge change during the growth process, with a peak when the lumps have sizes of a few meters. For this reason, meter-sized structures are expected to be the most compact and resilient, and it is particularly interesting that the comet material appears lumpy on that particular size scale.
- Further lines of evidence include spectral analysis of the comet's composition showing that the surface has experienced little or no in situ alteration by liquid water, and analysis of the gases ejected from sublimating ices buried deeper within the surface, which finds the comet to be rich in supervolatiles such as carbon monoxide, oxygen, nitrogen and argon.
- These observations imply that comets formed in extremely cold conditions and did not experience significant thermal processing during most of their lifetimes. Instead, to explain the low temperatures, survival of certain ices and retention of supervolatiles, they must have accumulated slowly over a significant time period.
- "While larger TNOs in the outer reaches of the Solar System appear to have been heated by short-lived radioactive substances, comets don't seem to show similar signs of thermal processing. We had to resolve this paradox by taking a detailed look at the time line of our current Solar System models, and consider new ideas," says Björn. Björn and colleagues propose that the larger members of the TNO population formed rapidly within the first one million years of the solar nebula, aided by turbulent gas streams that rapidly accelerated their growth to sizes of up to 400 km.
- Around three million years into the Solar System's history, gas had disappeared from the solar nebula, only leaving solid material behind. Then, over a much longer period of around 400 million years, the already massive TNOs slowly accreted further material and underwent compaction into layers, their ices melting and refreezing, for example. Some TNOs even grew into Pluto or Triton-sized objects.
- Comets took a different path. After the rapid initial growth phase of the TNOs, leftover grains and 'pebbles' of icy material in the cold, outer parts of the solar nebula started to come together at low velocity, yielding comets roughly 5 km in size by the time gas has disappeared from the solar nebula. The low speeds at which the material accumulated led to objects with fragile nuclei with high porosity and low density. - This slow growth also allowed comets to preserve some of the oldest, volatile-rich material from the solar nebula, since they were able to release the energy generated by radioactive decay inside them without heating up too much.
- The larger TNOs played a further role in the evolution of comets. By 'stirring' the cometary orbits, additional material was accreted at somewhat higher speed over the next 25 million years, forming the outer layers of comets. The stirring also made it possible for the few kilometer-sized objects in size to bump gently into each other, leading to the bi-lobed nature of some observed comets.
- "Comets do not appear to display the characteristics expected for collisional rubble piles, which result from the smash-up of large objects like TNOs. Rather, we think they grew gently in the shadow of the TNOs, surviving essentially undamaged for 4.6 billion years," concludes Björn. "Our new model explains what we see in Rosetta's detailed observations of its comet, and what had been hinted at by previous comet flyby missions."
- "Comets really are the treasure-troves of the Solar System," adds Matt. "They give us unparalleled insight into the processes that were important in the planetary construction yard at these early times and how they relate to the Solar System architecture that we see today."
Figure 109: Profile of a primordial comet (image credit: Center: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0; Insets: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Fornasier et al. (2015); ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S; Langevin et al. (2016))
• On July 27, 2016, the ESS (Electrical Support System) on Rosetta, which is used to communicate with Philae, will be switched off to save energy before September 30, the day the Rosetta mission will come to an end. 142)
• July 15, 2016: This CometWatch image (Figure 110) was taken with Rosetta's NAVCAM on 9 July 2016, when the spacecraft was 11.7 km from the nucleus of Comet 67P/Churyumov-Gerasimenko. The close-up view shows a portion of the Khonsu region on the larger of the two comet lobes. Khonsu is part of the southern hemisphere of 67P/C-G. 143)
- The image reveals a variety of fractured and smooth terrains, with a great number of boulders of all sizes, including several large ones. It also includes a three-layered structure with a balancing boulder on top, which was also portrayed in previous images, for example the NAVCAM view featured as CometWatch 13 June, which shows the same region but from a broader perspective.
Figure 110: Enhanced NAVCAM image of Comet 67P/C-G taken on 9 July 2016, 11.7 km from the nucleus. The scale is 1 m/pixel and the image measures about 1 km (image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0)
• June 30, 2016: Rosetta is set to complete its mission in a controlled descent to the surface of its comet on 30 September. The mission is coming to an end as a result of the spacecraft's ever-increasing distance from the Sun and Earth. It is heading out towards the orbit of Jupiter, resulting in significantly reduced solar power to operate the craft and its instruments, and a reduction in bandwidth available to downlink scientific data. 144)
- Combined with an ageing spacecraft and payload that have endured the harsh environment of space for over 12 years – not least two years close to a dusty comet – this means that Rosetta is reaching the end of its natural life.
- Unlike in 2011, when Rosetta was put into a 31-month hibernation for the most distant part of its journey, this time it is riding alongside the comet. Comet 67P/Churyumov-Gerasimenko's maximum distance from the Sun (over 850 million km) is more than Rosetta has ever journeyed before. The result is that there is not enough power at its most distant point to guarantee that Rosetta's heaters would be able to keep it warm enough to survive.
- Instead of risking a much longer hibernation that is unlikely to be survivable, and after consultation with Rosetta's science team in 2014, it was decided that Rosetta would follow its lander Philae down onto the comet.
- The final hours of descent will enable Rosetta to make many once-in-a-lifetime measurements, including very-high-resolution imaging, boosting Rosetta's science return with precious close-up data achievable only through such a unique conclusion. — Communications will cease, however, once the orbiter reaches the surface, and its operations will then end.
- "We're trying to squeeze as many observations in as possible before we run out of solar power," says Matt Taylor, ESA Rosetta project scientist. "30 September will mark the end of spacecraft operations, but the beginning of the phase where the full focus of the teams will be on science. That is what the Rosetta mission was launched for and we have years of work ahead of us, thoroughly analyzing its data."
- Rosetta's operators will begin changing the trajectory in August ahead of the grand finale such that a series of elliptical orbits will take it progressively nearer to the comet at its closest point.
- "Planning this phase is in fact far more complex than it was for Philae's landing," says Sylvain Lodiot, ESA Rosetta spacecraft operations manager. "The last six weeks will be particularly challenging as we fly eccentric orbits around the comet – in many ways this will be even riskier than the final descent itself. - "The closer we get to the comet, the more influence its non-uniform gravity will have, requiring us to have more control on the trajectory, and therefore more maneuvers – our planning cycles will have to be executed on much shorter timescales."
- A number of dedicated maneuvers in the closing days of the mission will conclude with one final trajectory change at a distance of around 20 km about 12 hours before impact, to put the spacecraft on its final descent.
- In the meantime, science will continue as normal, although there are still many risks ahead. Last month, the spacecraft experienced a 'safe mode' while only 5 km from the comet as a result of dust confusing the navigation system. Rosetta recovered, but the mission team cannot rule out this happening again before the planned end of the mission.
• May 27, 2016: Ingredients regarded as crucial for the origin of life on Earth have been discovered at the comet that ESA's Rosetta spacecraft has been probing for almost two years. They include the amino acid glycine, which is commonly found in proteins, and phosphorus, a key component of DNA and cell membranes. 145) 146)
- Scientists have long debated the important possibility that water and organic molecules were brought by asteroids and comets to the young Earth after it cooled following its formation, providing some of the key building blocks for the emergence of life. While some comets and asteroids are already known to have water with a composition like that of Earth's oceans, Rosetta found a significant difference at its comet – fuelling the debate on their role in the origin of Earth's water.
- But new results reveal that comets nevertheless had the potential to deliver ingredients critical to establish life as we know it. Amino acids are biologically important organic compounds containing carbon, oxygen, hydrogen and nitrogen, and form the basis of proteins.
- Hints of the simplest amino acid, glycine, were found in samples returned to Earth in 2006 from Comet Wild-2 by NASA's Stardust mission. However, possible terrestrial contamination of the dust samples made the analysis extremely difficult.
- Now, Rosetta has made direct, repeated detections of glycine in the fuzzy atmosphere or 'coma' of its comet. "This is the first unambiguous detection of glycine at a comet," says Kathrin Altwegg, principal investigator of the ROSINA instrument that made the measurements, and lead author of the paper. "At the same time, we also detected certain other organic molecules that can be precursors to glycine, hinting at the possible ways in which it may have formed."
- The measurements were made before the comet reached its closest point to the Sun – perihelion – in August 2015 in its 6.5 year orbit. The first detection was made in October 2014 while Rosetta was just 10 km from the comet. The next occasion was during a flyby in March 2015, when it was 30–15 km from the nucleus.
- A sample mass spectrum at 75, 45, 31, and 30 dalton is shown in Figure111. The number of ionized particles registered on the detector is given as a function of the position on the detector, which corresponds to mass/charge ratio (m/z). Glycine (C2H5NO2), methylamine (CH5N), and ethylamine (C2H7N) can be found on mass 75, 31, and 45 dalton, respectively.
- Glycine was also seen on other occasions associated with outbursts from the comet in the month leading up to perihelion, when Rosetta was more than 200 km from the nucleus but surrounded by a lot of dust. "We see a strong link between glycine and dust, suggesting that it is probably released perhaps with other volatiles from the icy mantles of the dust grains once they have warmed up in the coma," says Kathrin.
- Glycine turns into gas only when it reaches temperatures just below 150°C, meaning that usually little is released from the comet's surface or subsurface because of the low temperatures. This accounts for the fact that Rosetta does not always detect it. "Glycine is the only amino acid that is known to be able to form without liquid water, and the fact we see it with the precursor molecules and dust suggests it is formed within interstellar icy dust grains or by the ultraviolet irradiation of ice, before becoming bound up and conserved in the comet for billions of years," adds Kathrin.
- Another exciting detection made by Rosetta and described in the paper is of phosphorus, a key element in all known living organisms. For example, it is found in the structural framework of DNA, in cell membranes and in transporting chemical energy within cells for metabolism. "There is still a lot of uncertainty regarding the chemistry on early Earth and there is of course a huge evolutionary gap to fill between the delivery of these ingredients via cometary impacts and life taking hold," says co-author Hervé Cottin. "But the important point is that comets have not really changed in 4.5 billion years: they grant us direct access to some of the ingredients that likely ended up in the prebiotic soup that eventually resulted in the origin of life on Earth."
- "The multitude of organic molecules already identified by Rosetta, now joined by the exciting confirmation of fundamental ingredients like glycine and phosphorous, confirms our idea that comets have the potential to deliver key molecules for prebiotic chemistry," says Matt Taylor, ESA's Rosetta project scientist.
Figure 111: ROSINA DFMS (Double Focusing Mass Spectrometer) mass spectra (9 July 2015) for masses 30, 31, 45, and 75 dalton. Integration time is 20 s per spectrum. Error bars represent 1σ counting statistics (image credit: Rosetta/ROSINA Team)
• April 18, 2016: Captured in this curious view (Figure 112) are the Anuket region and its surroundings on Comet 67P/Churyumov–Gerasimenko. The image was taken by Rosetta’s navigation camera (NavCam) on 13 March 2016, from a distance of 17 km, and measures about 1.5 km across. 147)
- However, if we briefly suspend disbelief and set our imagination free, we might be tricked into recognizing the profile of a face, with the forehead and eyebrows on the left, a nose pointing upwards and even the hint of a smile. This is an effect of pareidolia, a psychological phenomenon whereby humans tend to identify familiar shapes in the vague patterns of random images.
- In reality, the fictional face shows the rough landscape of Anuket, a region of rugged terrains on the small comet lobe and declining towards the large lobe, which is located beyond the lower-right corner of the image. What might appear as a forehead, towards the left, is in fact the surface of Serqet, a small region comprising flat and smooth terrains and a few boulders. The sharp cliff separating Serqet and Anuket contributes to the optical illusion, suggesting the profile of an eye socket and eyebrow.
- Along the sharp boundary between Serqet and Anuket – the eyebrow – is a round, crescent feature, known as C. Alexander Gate. It is dedicated to Dr Claudia J. Alexander, who was the US Rosetta Project Scientist and passed away in July 2015.
- The image also depicts Serqet casting a dramatic shadow onto parts of Ma’at, the smooth, dusty region visible in the lower-right part of the image. Another striking element is the border between Ma’at and Anuket, highlighting the difference between the almost featureless appearance of Ma’at and the rugged terrains of Anuket.
- A hint of the Hathor region is also visible, albeit cast in shadow, on the lower part of the image. You can use the comet viewer tool to aid navigation around the comet’s regions.
- Rosetta is currently around 30 km from the nucleus, and will continue studying the comet from up close until the end of September, when it will be maneuvered into a controlled impact on the comet.
Figure 112: Image of the Anuket region and its surroundings on Comet 67P/Churyumov–Gerasimenko, acquired on March 13, 2016 with the NAVCAM from a distance of 17 km (image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0)
• April 7, 2016: Comet 67P/Churyumov-Gerasimenko was seen changing color and brightness by Rosetta’s VIRTIS (Visible and InfraRed Thermal Imaging Spectrometer), as more water-ice was exposed near its surface as it moved close to the Sun between August and November 2014. 148) 149)
- In the three-month study period the comet moved from about 542 million km to 438 million km from the Sun, and the spacecraft-to-comet distance varied from about 100 km to 10 km, resulting in a range of illumination conditions and viewing geometries. In general, the darkest portions of the comet, containing dry dust made out of a mixture of minerals and organics, reflect light at redder wavelengths, while active regions and the occasional ice-rich exposure is bluer.
- The VIRTIS study shows that even in the first three months of study at the comet, global average changes are noticeable, with an overall trend of the comet becoming brighter and more water-ice-rich. This is particularly notable in the Imhotep region, which becomes overall bluer over time.
Figure 113: Illustration of the comet's orbit in the period August-November 2014 (image credit: ESA/ATG medialab)
Figure 114: Comet 67p/Churyumov-Gerasimenko was seen changing color and brightness as more water-ice was exposed near its surface as it moved closer to the Sun between August and November 2014 (image credit: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS De PARIS-LESIA/DLR; G. Filacchione et al., 2016)
Legend to Figure 114: Variation of visible spectral slope (color) over time. Red corresponds to more organic-rich material; blue indicates more active regions (such as Hapi) and water-ice rich exposures. The transition from redder to bluer spectra is most clearly seen in the Imhotep region.
• March 11, 2016: ESA’s Rosetta spacecraft has revealed a surprisingly large region around its host comet devoid of any magnetic field. The Rosetta magnetometer RPC-MAG has been exploring the plasma environment of comet 67P/Churyumov-Gerasimenko since August 2014. The first months were dominated by low-frequency waves which evolved into more complex features. However, at the end of July 2015, close to perihelion, the magnetometer detected a region that did not contain any magnetic field at all. 150) 151)
- These signatures match the appearance of a diamagnetic cavity as was observed at comet 1P/Halley in 1986 when ESA's Giotto found a vast magnetic-free region extending more than 4000 km from the nucleus. This was the first observation of something that scientists had until then only thought about but had never seen.
- The cavity at Rosetta is more extended than previously predicted by models and features unusual magnetic field configurations, which need to be explained. According to the team's analysis of the data acquired by the Rosetta Plasma Consortium instrumentation confirms the existence of a diamagnetic cavity. However, the size is larger than predicted by simulations. One possible explanation are instabilities that are propagating along the cavity boundary and possibly a low magnetic pressure in the solar wind. This conclusion is supported by a change in sign of the Sun-pointing component of the magnetic field. Evidence also indicates that the cavity boundary is moving with variable velocities ranging from 230-500 m/s.
Figure 115: Artist's rendition of the magnetic field-free cavity discovered by Rosetta at Comet 67P/Churyumov-Gerasimenko (image credit: ESA, C. Carreau)
Legend to Figure 115: The magnetic field-free region, shown here in blue, is caused by the interaction of the comet and the solar wind, shown in purple. The solar wind is a flow of electrically charged particles streaming from the Sun (located beyond the left edge of the image) and carrying its magnetic field across the Solar System. When it approaches the comet, which is pouring lots of gas into space, its flow is obstructed and slowed. Eventually, the solar wind stops entirely, diverting its flow around the comet, and also its magnetic field is unable to penetrate the environment around the comet, creating a region devoid of magnetic field called a diamagnetic cavity. — Scientists expected that such a diamagnetic cavity could form at Rosetta’s comet around perihelion, but only extend to 50–100 km from the nucleus, and since the spacecraft was at greater distances from the comet at the time, they did not expect to detect it. Instead, they measured almost 700 magnetic field-free regions with the RPC-MAG magnetometer on Rosetta since June 2015, revealing that the cavity is much bigger than expected. The reason for that is likely an oscillating perturbation, or instability (thin wiggly line), that propagates and gets amplified along the boundary (thick line) between the solar wind and the magnetic field-free cavity, causing the latter to grow in size and allowing Rosetta to detect it.
- Prior to Rosetta arriving at Comet 67P/Churyumov-Gerasimenko, scientists had hoped to observe such a magnetic field-free region in the environment of this comet. The spacecraft carries a magnetometer as part of the Rosetta Plasma Consortium suite of sensors (RPC-MAG), whose measurements were already used to demonstrate that the comet nucleus is not magnetized.
- However, since Rosetta’s comet is much less active than Comet Halley, the scientists predicted that a diamagnetic cavity could form only in the months around perihelion – the closest point to the Sun on the comet’s orbit – but that it would extend only 50–100 km from the nucleus. During 2015, the increased amounts of dust dragged into space by the outflowing gas became a significant problem for navigation close to the comet. To keep Rosetta safe, trajectories were chosen such that by the end of July 2015, a few weeks before perihelion, it was some 170 km away from the nucleus. As a result, scientists considered that detecting signs of the magnetic field-free bubble would be impossible.
- “We had almost given up on Rosetta finding the diamagnetic cavity, so we were astonished when we eventually found it,” says Charlotte Götz of the Institute for Geophysics and extraterrestrial Physics in Braunschweig, Germany. Charlotte is the lead author of a new study, published in the journal Astronomy and Astrophysics. “We were able to detect the cavity, on many occasions, because it is much bigger and dynamic than we had expected,” adds Charlotte.
Figure 116: The decrease in magnetic field strength measured by Rosetta’s RPC-MAG instrument at Comet 67P/Churyumov–Gerasimenko on 26 July 2015 at a distance of about 170 km from the comet (image credit: ESA/Rosetta/RPC/IGEP/IC)
• Feb. 12, 2016: Silent since its last call to mothership Rosetta seven months ago, the Philae lander is facing conditions on Comet 67P/Churyumov–Gerasimenko from which it is unlikely to recover. 152) 153)
- Rosetta, which continues its scientific investigations at the comet until September before its own comet-landing finale, has in recent months been balancing science observations with flying dedicated trajectories optimized to listen out for Philae. But the lander has remained silent since 9 July 2015.
- “The chances for Philae to contact our team at our lander control center are unfortunately getting close to zero,” says Stephan Ulamec, Philae project manager at the German Aerospace Center, DLR. “We are not sending commands any more and it would be very surprising if we were to receive a signal again.”
- Philae’s team of expert engineers and scientists at the German, French and Italian space centers and across Europe have carried out extensive investigations to try to understand the status of the lander, piecing together clues since it completed its first set of scientific activities after its historic landing on 12 November 2014.
- A story with incredible twists and turns unfolded on that day. In addition to a faulty thruster, Philae also failed to fire its harpoons and lock itself onto the surface of the comet after its seven-hour descent, bouncing from its initial touchdown point at Agilkia, to a new landing site, Abydos, over 1 km away. The precise location of the lander has yet to be confirmed in high-resolution images.
- A reconstruction of the flight of the lander suggested that it made contact with the comet four times during its two-hour additional flight across the small comet lobe. After bouncing from Agilkia it grazed the rim of the Hatmehit depression, bounced again, and then finally settled on the surface at Abydos (Figure 140).
- Even after this unplanned excursion, the lander was still able to make an impressive array of science measurements, with some even as it was flying above the surface after the first bounce.
- Once the lander had made its final touchdown, science and operations teams worked around the clock to adapt the experiments to make the most of the unanticipated situation. About 80% of its initial planned scientific activities were completed.
- In the 64 hours following its separation from Rosetta, Philae took detailed images of the comet from above and on the surface, sniffed out organic compounds, and profiled the local environment and surface properties of the comet, providing revolutionary insights into this fascinating world.
- But with insufficient sunlight falling on Philae’s new home to charge its secondary batteries, the race was on to collect and transmit the data to Rosetta and across 510 million km of space back to Earth before the lander’s primary battery was exhausted as expected. Thus, on the evening of 14–15 November 2014, Philae fell into hibernation.
- The last images of Philae will probably be acquired in the summer of 2016, when the Rosetta spacecraft images the lander during close fly-bys. "When we see how Philae is positioned, we will be able to better interpret certain data, such as the measurements of the CONSERT radar experiment." In approximately six years, Philae and Rosetta, which will be landed on the comet in September 2016 at the end of its mission, will be closer to Earth – and Comet 67/P Churyumov-Gerasimenko will have circled the Sun once again.
• Feb. 4, 2016: There are no large caverns inside Comet 67P/Churyumov-Gerasimenko. ESA’s Rosetta mission has made measurements that clearly demonstrate this, solving a long-standing mystery. Comets are the icy remnants left over from the formation of the planets 4.6 billion years ago. A total of eight comets have now been visited by spacecraft and, thanks to these missions, we have built up a picture of the basic properties of these cosmic time capsules. While some questions have been answered, others have been raised. 154)
- Comets are known to be a mixture of dust and ice, and if fully compact, they would be heavier than water. However, previous measurements have shown that some of them have extremely low densities, much lower than that of water ice. The low density implies that comets must be highly porous. But is the porosity because of huge empty caves in the comet’s interior or it is a more homogeneous low-density structure?
- In a new study led by Martin Pätzold, the authors have shown that Comet 67P/Churyumov-Gerasimenko is also a low-density object, but they have also been able to rule out a cavernous interior. This result is consistent with earlier results from Rosetta’s CONSERT radar experiment showing that the double-lobed comet’s ‘head’ is fairly homogenous on spatial scales of a few tens of meters. 155)
- The most reasonable explanation then is that the comet’s porosity must be an intrinsic property of dust particles mixed with the ice that make up the interior. In fact, earlier spacecraft measurements had shown that comet dust is typically not a compacted solid, but rather a ‘fluffy’ aggregate, giving the dust particles high porosity and low density, and Rosetta’s COSIMA and GIADA instruments have shown that the same kinds of dust grains are also found at 67P/Churyumov-Gerasimenko.
- Pätzold’s study team made their discovery by using the RSI (Radio Science Experiment) to study the way the Rosetta orbiter is pulled by the gravity of the comet, which is generated by its mass. The effect of the gravity on the movement of Rosetta is measured by changes in the frequency of the spacecraft’s signals when they are received at Earth. It is a manifestation of the Doppler effect, produced whenever there is movement between a source and an observer, and is the same effect that causes emergency vehicle sirens to change pitch as they pass by.
- In this case, Rosetta was being pulled by the gravity of the comet, which changed the frequency of the radio link to Earth. ESA’s 35 m antenna at the New Norcia ground station in Australia is used to communicate with Rosetta during routine operations. The variations in the signals it received were analyzed to give a picture of the gravity field across the comet. Large internal caverns would have been noticeable by a tell-tale drop in acceleration.
- ESA’s Rosetta mission is the first to perform this difficult measurement for a comet. “Newton’s law of gravity tells us that the Rosetta spacecraft is basically pulled by everything,” says Martin Pätzold, the principal investigator of the RSI experiment. “In practical terms, this means that we had to remove the influence of the Sun, all the planets – from giant Jupiter to the dwarf planets – as well as large asteroids in the inner asteroid belt, on Rosetta’s motion, to leave just the influence of the comet. Thankfully, these effects are well understood and this is a standard procedure nowadays for spacecraft operations.”
- Next, the pressure of the solar radiation and the comet’s escaping gas tail has to be subtracted. Both of these ‘blow’ the spacecraft off course. In this case, Rosetta’s ROSINA instrument is extremely helpful as it measures the gas that is streaming past the spacecraft. This allowed Pätzold and his colleagues to calculate and remove those effects too.
- Whatever motion is left is due to the comet’s mass. For Comet 67P/Churyumov-Gerasimenko, this gives a mass slightly less than 10 billion tons. Images from the OSIRIS camera have been used to develop models of the comet’s shape and these give the volume as around 18.7 km3, meaning that the density is 533 kg/m3.
- Extracting the details of the interior was only possible through a piece of cosmic good luck. The comet’s strange shape was revealed as Rosetta drew nearer for its rendezvous in August 2014. Luckily for RSI, the double-lobed structure meant that the differences in the gravity field would be much more pronounced, and therefore easier to measure from far away.
- In September 2016, Rosetta will be guided to a controlled impact on the surface of the comet. The maneuver will provide a unique challenge for the flight dynamics specialists at ESA/ESOC (European Space Operations Center) in Darmstadt, Germany. As Rosetta gets nearer and nearer, the complex gravity field of the comet will make navigating harder and harder. But for RSI, its measurements will increase in precision. This could allow the team to check for caverns just a few hundred meters across.
• January 13, 2016: Observations made shortly after Rosetta’s arrival at its target comet in 2014 have provided definitive confirmation of the presence of water ice. Although water vapor is the main gas seen flowing from comet 67P/Churyumov–Gerasimenko, the great majority of ice is believed to come from under the comet’s crust, and very few examples of exposed water ice have been found on the surface. However, a detailed analysis by Rosetta’s VIRTIS infrared instrument reveals the composition of the comet’s topmost layer: it is primarily coated in a dark, dry and organic-rich material but with a small amount of water ice mixed in. 156) 157)
- In the latest study, which focuses on scans between September and November 2014, the team confirms that two areas several tens of meters across in the Imhotep region that appear as bright patches in visible light, do indeed include a significant amount of water ice. The ice is associated with cliff walls and debris falls, and was at an average temperature of about –120ºC at the time.
- In those regions, pure water ice was found to occupy around 5% of each pixel sampling area, with the rest made up of the dark, dry material. The abundance of ice was calculated by comparing Rosetta’s VIRTIS infrared measurements to models that consider how ice grains of different sizes might be mixed together in one pixel.
- The data reveal two different populations of grains: one is several tens of micrometers in diameter, while the other is larger, around 2 mm. These sizes contrast with the very small grains, just a few micrometers in diameter, found in the Hapi region on the ‘neck’ of the comet, as observed by VIRTIS in a different study.
- The Rosetta scientists are now analyzing data captured later in the mission, as the comet moved closer to the Sun in mid-2015, to see how the amount of ice exposed on the surface evolved as the heating increased.
Figure 117: Two exposures of water ice identified by Rosetta’s VIRTIS instrument in the Imhotep region of Comet 67P/Churyumov–Gerasimenko in September–November 2014 (image credit: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0)
Legend to Figure 117: The main image was taken on 17 September 2014 from a distance of about 28.8 km from the comet center. The two insets show oblique views of the two icy exposures. The left hand image was taken on 20 September 2014 from a distance of 27.9 km. The right hand image was taken on 15 September 2014 from a distance of 29.9 km.
• Dec. 31, 2015: Images from Rosetta taken over the holiday period. 158)
Figure 118: The single-frame OSIRIS narrow-angle camera image was taken on 31 December 2015, when Rosetta was 79.6 km from the nucleus of Comet 67P/Churyumov–Gerasimenko. The scale is 1.44 m/pixel (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
• Nov. 30, 2015: A new 3D shape model of Comet 67P/Churyumov-Gerasimenko has been released by ESA’s Rosetta archive team (Figure 119). The model includes images taken by Rosetta’s NAVCAM up until mid-late July 2015, and reveals parts of the comet’s southern hemisphere that were not included in earlier shape models. 159)
Figure 119: The updated shape model of Comet 67P/Churyumov-Gerasimenko includes recent images of the comet’s southern hemisphere (image credit: ESA/Rosetta/NAVCAM, CC BY-SA IGO 3.0)
• November 12, 2015: As announced in June 2015 along with confirmation of the mission’s extension, Rosetta teams are planning to end the operational phase of the mission in a controlled impact of the orbiter on the surface of Comet 67P/Churyumov-Gerasimenko at the end of September 2016. While the specific details of the trajectories and impact site are still under discussion, ESA’s Rosetta Spacecraft Operations Manager Sylvain Lodiot, Project Scientist Matt Taylor, and mission manager Patrick Martin, share some background information on the planning of this dramatic mission finale. 160)
• Nov. 12, 2015: One year since Philae made its historic landing on a comet, mission teams remain hopeful for renewed contact with the lander, while also looking ahead to next year’s grand finale: making a controlled impact of the Rosetta orbiter on the comet. - Rosetta arrived at Comet 67P/Churyumov–Gerasimenko on 6 August 2014, and after an initial survey and selection of a landing site, Philae was delivered to the surface on 12 November. 161) 162) 163)
- After touching down in the Agilkia region as planned (Figure 120), Philae did not secure itself to the comet, and it bounced to a new location in Abydos. Its flight across the surface is depicted in a new animation, using data collected by Rosetta and Philae to reconstruct the lander’s rotation and attitude.
- In the year since landing, a thorough analysis has also now been performed on why Philae bounced. There were three methods to secure it after landing: ice screws, harpoons and a small thruster. The ice screws were designed with relatively soft material in mind, but Agilkia turned out to be very hard and they did not penetrate the surface.
- The harpoons were capable of working in both softer and harder material. They were supposed to fire on contact and lock Philae to the surface, while a thruster on top of the lander was meant to push it down to counteract the recoil from the harpoon. - Attempts to arm the thruster the night before failed: it is thought that a seal did not open, although a sensor failure cannot be excluded.
- Then, on landing, the harpoons themselves did not fire. “It seems that the problem was either with the four ‘bridge wires’ taking current to ignite the explosive that triggers the harpoons, or the explosive itself, which may have degraded over time,” explains Stephan Ulamec, Philae lander manager at the DLR German Aerospace Center. “In any case, if we can regain contact with Philae, we might consider an attempt to retry the firing.”
- The reason is scientific: the harpoons contain sensors that could measure the temperature below the surface. Despite the unplanned bouncing, Philae completed 80% of its planned first science sequence before falling into hibernation in the early hours of 15 November when the primary battery was exhausted. There was not enough sunlight in Philae’s final location at Abydos to charge the secondary batteries and continue science measurements.
- The hope was that as the comet moved nearer to the Sun, heading towards closest approach in August, there would be enough energy to reactivate Philae. Indeed, contact was made with the lander on 13 June 2015 but only eight intermittent contacts were made up to 9 July. The problem was that the increasing sunlight also led to increased activity on the comet, forcing Rosetta to retreat to several hundred kilometers for safety, well out of range with Philae.
- However, over the past few weeks, with the comet’s activity now subsiding, Rosetta has started to approach again. This week it reached 200 km, the limit for making good contact with Philae, and today it dips to within 170 km.
- In the meantime, the lander teams have continued their analysis of the data returned during the contacts in June and July, hoping to understand the status of Philae when it first woke up from hibernation. “We had already determined that one of Philae’s two receivers and one of the two transmitters were likely no longer working,” says Koen Geurts, Philae’s technical manager at DLR’s Lander Control Center in Cologne, Germany, “and it now seems that the other transmitter is suffering problems. Sometimes it did not switch on as expected, or it switched off too early, meaning that we likely missed possible contacts.” The team is taking this new information into account to determine the most promising strategy to regain regular contact. But it’s a race against time: with the comet now heading out beyond the orbit of Mars, temperatures are falling.
Figure 120: The area surrounding Philae’s first touchdown point, Agilkia (circled) on comet 67P/Churyumov–Gerasimenko. The large depression is the Hatmehit region. The dashed line marks the comet’s equator. This image is a composite of five frames from the OSIRIS narrow-angle camera (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
• October 2015 (Flight dynamics analysis for the approach of Rosetta with the comet): When the Rosetta spacecraft approached comet Churyumov-Gerasimenko in August 2014 after ten years of flight, almost nothing was known about its target’s gravity field and rotation, except for the rotation period. Since knowledge of these parameters is essential for trajectory design, a flexible strategy had to be devised to cope with a large range of possible values. In addition, the strategy had to be robust against contingencies like missed orbit maneuvers. The first simulations showed that the initial plan was not feasible. After several iterations, a strategy meeting these requirements was found. It consisted of a Comet Approach Phase, where the relative velocity was gradually reduced by orbit maneuvers of decreasing size, and an Initial Characterization Phase, where the physical parameters of the comet were determined from a sequence of hyperbolic arcs forming a pyramid-like orbit. These parameters would subsequently be used to adapt the trajectories for the next phase of the mission, where the spacecraft would be put into a bound orbit around the comet. The strategy chosen was successfully validated by a navigation analysis in which the operations that would be performed during the real approach were simulated, and finally confirmed when it was put into action during the real operations. 164)
- In preparation for the approach of spacecraft Rosetta to comet 67P/Churyumov-Gerasimenko, an extensive number of simulations were performed. These included both closed-loop and open-loop simulations, where the more realistic closed-loop simulations were used to validate the idea of open-loop simulations, which are less realistic but require less effort.
- The first simulations clearly indicated that the original plan, which foresaw a direct insertion into a bound orbit at the end of the approach phase, was not feasible since the comet mass and attitude could not be determined with sufficient accuracy before the insertion maneuver. Instead, after several iterations, a new strategy was devised: The initial characterization of the comet was done from hyperbolic arcs at cometocentric distances between 50 and 120 km. The velocity in these arcs was chosen such that the influence of the initially poorly known comet gravity force on the spacecraft orbit was large enough to provide an accurate determination of the comet mass, but still small enough to allow a reasonably accurate orbit prediction. Orbit maneuvers were performed regularly to keep the spacecraft close to the comet, in such a way that the comet-spacecraft vector formed two pyramids with the nucleus at the apex.
- From these pyramid orbits, the mass, rotational state and shape of the comet could be estimated. Moreover, landmarks on the surface of the nucleus could be identified with sufficient accuracy for a safe insertion into a bound orbit. Following the insertion, the spacecraft entered the Global Mapping and the Close Observation phases, in which the knowledge about the comet properties was further improved by observations from successively closer orbits around the comet.
- The validity of the revised strategy was finally fully confirmed when it was put into action during the actual operations, without the need for any modifications. All orbit maneuvers during the approach performed well within the expected uncertainties (165) 166)), the comet was detected at the earliest possible stage using the OSIRIS NAC and the derivation of optical measurements from the camera images worked flawlessly. 167) 168)
• October 28, 2015: ESA’s Rosetta spacecraft has made the first in situ detection of oxygen molecules outgassing from a comet, a surprising observation that suggests they were incorporated into the comet during its formation. Rosetta has been studying Comet 67P/Churyumov–Gerasimenko for over a year and has detected an abundance of different gases pouring from its nucleus. Water vapor, carbon monoxide and carbon dioxide are the most prolific, with a rich array of other nitrogen-, sulphur- and carbon-bearing species, and even ‘noble gases’ also recorded. 169) 170)
- Oxygen is the third most abundant element in the Universe, but the simplest molecular version of the gas, O2, has proven surprisingly hard to track down, even in star-forming clouds, because it is highly reactive and readily breaks apart to bind with other atoms and molecules. For example, oxygen atoms can combine with hydrogen atoms on cold dust grains to form water, or a free oxygen split from O2 by ultraviolet radiation can recombine with an O2 molecule to form ozone (O3).
- Despite its detection on the icy moons of Jupiter and Saturn, O2 had been missing in the inventory of volatile species associated with comets until now. “We weren’t really expecting to detect O2 at the comet – and in such high abundance – because it is so chemically reactive, so it was quite a surprise,” says Kathrin Altwegg of the University of Bern, and principal investigator of the ROSINA-DFMS (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis-Double Focusing Mass Spectrometer) instrument.
- The research team analyzed more than 3000 samples collected around the comet between September 2014 and March 2015 to identify the O2. They determined an abundance of 1–10% relative to H2O, with an average value of 3.80 ± 0.85%, an order of magnitude higher than predicted by models describing the chemistry in molecular clouds. The amount of molecular oxygen detected showed a strong relationship to the amount of water measured at any given time, suggesting that their origin on the nucleus and release mechanism are linked. By contrast, the amount of O2 seen was poorly correlated with carbon monoxide and molecular nitrogen, even though they have a similar volatility to O2. In addition, no ozone was detected.
Figure 121: Rosetta has made the first detection of molecular oxygen at a comet. The results presented in this graphic are based on ROSINA-DFMS observations between September 2014 and March 2015 when Rosetta was still on the approach to the Sun along its orbit (image credit: Spacecraft: ESA/ATG medialab; comet: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0; Data: A. Bieler et al. (2015)
October 2015 (Rosetta navigation during lander delivery phase and
reconstruction of Philae descent trajectory and rebound): 171) 172)
- Rosetta’s SPD (Lander Delivery Phase) started on October 28, 2014 with the execution of the SDP-1 maneuver that drove the spacecraft away from the “Close Observation” 10 km orbit, in a transition arc to the 30 km parking orbit, in preparation for the lander delivery sequence to be executed on November 12. The main objectives of this phase were: to safely deliver Philae into its descent trajectory towards the target landing site; to keep the communication link with the lander during descent and immediately after landing; and additionally to take images of the lander’s descent and landing.
- Trajectory: Figure 122 shows, in white, the terminator orbits flown by Rosetta the month before lander delivery (from 20 km to 10 km distance); and in red the trajectory flown by Rosetta for lander delivery:
Figure 122: Lander Delivery trajectory: Rosetta (red), Philae (green). Views from Sun direction (left) and close to the terminator plane (right), image credit: Rosetta navigation team, ESA
Legend to Figure 122: (1) Rosetta is inserted in a circular 30 km parking orbit with an orbital plane tilted 15º from the terminator plane (plane separating day/night). Rosetta flies almost a full orbit revolution around the comet, half of it spent in the night side of the comet (2). Once Rosetta arrives at the target point (3) for the initiation of the lander delivery sequence, the pre-delivery maneuver (83.6 cm/s) is executed, driving the S/C in a hyperbolic trajectory, almost in collision course, with 5 km miss-distance. A mission constraint did not allow to drive the orbiter in a collision trajectory to the comet, even if the plan included a subsequent maneuver that would avoid the collision.
At a distance of 22.6 km (4), Philae separates from Rosetta. The nominal separation’s relative velocity was 18.76 cm/s. Taking into account the mass of Rosetta and Philae and the fraction of Rosetta’s propellant intervening in the separation, it results that, nominally, the lander would receive a ΔV of 17.4 cm/s and Rosetta of 1.1 cm/s. The ΔV received by the lander redirected its trajectory towards the target point on the comet’s surface. The direction in which the separation is performed fixes the orientation of the lander’s Z-axis, which is stabilized by the angular momentum stored in its flywheel. The descent trajectory was designed such that at touchdown (7 hours after separation) the lander’s Z-axis was parallel to the local vertical (defined as the normal to the local surface), and that the incoming relative velocity with respect to the surface was also parallel to the local vertical.
In the meantime, Rosetta executes the post-delivery maneuver to avoid passing at 5 km distance from the comet, staying in the day side of the comet and ensuring communications with Philae during descent. Philae’s antenna is mounted pointing along the lander’s +Z axis and, by design, it is not pointing to Rosetta after separation. Therefore, a communication link during descent would not be possible if Rosetta did not execute the post-delivery maneuver. Afterwards, the mission enters in the Relay Phase (5), in which Rosetta performs a series of maneuvers to keep its trajectory in the region where the lander visibilities durations are maximized, in order to support the scientific operations of the lander on the comet’s surface.
- Navigation analysis: In the scope of the design of the lander delivery trajectory, navigation analysis was performed to assess the achievable landing accuracy. Monte Carlo simulations were run reproducing the navigation process: randomly generating a “real-world” trajectory; based on it, simulated observations are generated and fed to the OD (Orbit Determination); from the OD solution, the landing trajectory is optimized; and finally, the resulting maneuvers and separation conditions are perturbed and applied to the real-world to propagate the trajectory and compute the achieved landing point.
- The results of this analysis showed that the landing uncertainty was covering an area of roughly 500 m radius around the target landing point and that the uncertainty in the landing time was of about 40 min. Figure 123 shows the landing points of several simulated trajectories plotted on top of a NAVCAM image. 173)
Figure 123: Landing points of simulated trajectories plotted on top of a NAVCAM image (image credit: Rosetta navigation team, ESA
- On Nov. 12, 2014, Rosetta released Philae. The small lander, after 7 h descent, finally touched softly the ground of comet Churyumov-Gerasimenko. Unfortunately its anchoring system failed and Philae experienced a 2 h bouncing trajectory. It landed 1 km away from its target site. Nevertheless it was operated during 57 h performing its FSS (First Science Sequence. The FSS, made possible with the two batteries, should have been followed by the LTS (Long Term Science Sequence) but Philae was not well illuminated and fell “asleep”. One of the last Philae actions was to rotate its head slightly (+22° around Z axis) to improve solar arrays illumination. 174)
The wake-up of Philae occurred on June 13, 2015. A very short and unstable RF link was established between Philae and Rosetta. The lander was still not properly illuminated. The final position and attitude of Philae were key data to forecast an eventual wake-up. But as Philae was not equipped with system dedicated to position and attitude monitoring, the only way to determine missing data was to examine all collected measurements, housekeeping as well as scientific data. During the next weeks, Rosetta and Philae teams tried to assess the Philae’s status and to improve the RF links. Unfortunately, due to comet outgassing, it was not possible to reduce the distance between the two spacecrafts significantly. The last telecommunication occurred on July 9, 2015.
The Science Operation Navigation Center was responsible to coordinate and to realize activities necessary to determine the Philae attitude and position. Thanks to a collective effort, a possible landing area and an attitude were successfully estimated. Equivalent work was also realized to achieve the reconstruction, both of trajectory and attitude, of the descent and bouncing on the surface.
• Sept.28, 2015: Two comets collided at low speed in the early Solar System to give rise to the distinctive ‘rubber duck’ shape of Comet 67P/Churyumov–Gerasimenko, say Rosetta scientists. -The origin of the comet’s double-lobed form has been a key question since Rosetta first revealed its surprising shape in July 2014. Two leading ideas emerged: did two comets merge or did localized erosion of a single object form the ‘neck’? 175)
- Now, scientists have an unambiguous answer to the conundrum. By using high-resolution images taken between 6 August 2014 and 17 March 2015 to study the layers of material seen all over the nucleus, they have shown that the shape arose from a low-speed collision between two fully fledged, separately formed comets.
- “It is clear from the images that both lobes have an outer envelope of material organized in distinct layers, and we think these extend for several hundred meters below the surface,” says Matteo Massironi, lead author from the University of Padova, Italy, and an associate scientist of the OSIRIS team. “You can imagine the layering a bit like an onion, except in this case we are considering two separate onions of differing size that have grown independently before fusing together.”
- The results of the study are reported in the journal Nature and were presented on Sept. 28, 2015 at the European Planetary Science Congress in Nantes, France. 176)
Figure 124: Layers on the comet’s surface [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; M. Massironi et al. (2015)]
Legend to Figure 124: A selection of high-resolution OSIRIS images used to identify patterns in Comet 67P/Churyumov–Gerasimenko’s extensive layering.
- Top left: main terraces (green) and exposed layers (red dashed lines) seen in the Seth region on the comet’s large lobe. The terraces become more inclined towards the comet neck region. The close-up shows terraces in two locations (thin white and yellow arrows) together with examples of parallel lineaments (large white arrows) that define a continuous stratification.
- Bottom left: outline of exposed layers (red dashed lines) primarily in the Imhotep and Ash region on the comet’s large lobe. The terraces in Ash change their dip direction from that in Seth to very slightly dip towards Imhotep. Some layers are also indicated on the comet’s small lobe in the background. The close-up shows the details of the parallel layers in a section along the Imhotep-Ash boundary.
- Top right: main layers (red dashed lines) and cross-cutting fractures (blue dashed lines) in the Hathor cliff face on the comet’s small lobe. No abrupt change in the orientation of the layers is seen between Hathor and Ma’at. The close-up shows stratification in an alcove at the Hathor-Anuket boundary, providing a view of the Anuket inner structure, which appears to extend under Ma’at. Terraces on Anuket (white arrows) are seen in different orientations to neighboring regions. Taken together, this reinforces the idea that Hathor represents the inner comet structure that has been exposed, with Anuket as the remnant.
- Bottom right: layers (white dashed lines) at the boundary of Anubis and Seth on the comet’s large lobe. This continuous scarp suggests the thickness of the Seth region is about 150 m. The three arrow heads point to a terrace margin in Anubis and the single white arrow points to a terrace in the adjacent Atum region.
To reach their conclusion, Matteo and his colleagues first used images to identify over 100 terraces seen on the surface of the comet, and parallel layers of material clearly seen in exposed cliff walls and pits. A 3D shape model was then used to determine the directions in which they were sloping and to visualize how they extend into the subsurface.
It soon became clear that the features were coherently oriented all around the comet’s lobes and in some places extended to a depth of about 650 m. “This was the first clue that the two lobes are independent, reinforced by the observation that the layers are inclined in opposite directions close to the comet’s neck,” says Matteo. “To be sure, we also looked at the relationship between the local gravity and the orientations of the individual features all around the reconstructed comet surface.”
Broadly speaking, layers of material should form at right angles to the gravity of an object. The team used models to compute the strength and direction of the gravity at the location of each layer. In one case, they modelled the comet as a single body with a center of mass close to the neck. In the other, they worked with two separate comets, each with its own center of mass. The team found that orientation of a given layer and the direction of the local gravity are closer to perpendicular in the model with two separate objects, rather than in the one with a single combined nucleus (Ref. 175).
Figure 125: The comet’s two lobes [image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; M. Massironi et al. (2015)]
Legend to Figure 125: The methods used by Rosetta scientists to determine that Comet 67P/Churyumov–Gerasimenko’s shape arises from two separately forming comets.
- Left: high-resolution OSIRIS images were used to visually identify over 100 terraces (green) or strata – parallel layers of material (red dashed lines) – in exposed cliff walls and pits all over the comet surface (top: Hathor and surrounding regions on comet’s small lobe; bottom: Seth region on comet’s large lobe).
- Middle: a 3D shape model was used to determine the directions in which the terraces/strata are sloping and to visualize how they extend into the subsurface. The strata ‘planes’ are shown superimposed on the shape model (left panel) and alone (right panel) and show the planes coherently oriented all around the comet, in two separate bounding envelopes (scale bar indicates angular deviation between plane and local gravity vector).
- Right: local gravity vectors visualized on the comet shape model perpendicular to the terrace/strata planes further realize the independent nature of the two lobes (Ref. 175).
• Sept. 23, 2015: Comets are celestial bodies comprising a mixture of dust and ices, which they periodically shed as they swing towards their closest point to the Sun along their highly eccentric orbits. As sunlight heats the frozen nucleus of a comet, the ice in it – mainly water but also other 'volatiles' such as carbon monoxide and carbon dioxide – turns directly into a gas. This gas flows away from the comet, carrying dust particles along. Together, gas and dust build up the bright halo and tails that are characteristic of comets. 177)
- Rosetta arrived at Comet 67P/Churyumov–Gerasimenko in August 2014 and has been studying it up close for over a year. On 13 August 2015, the comet reached the closest point to the Sun along its 6.5-year orbit, and is now moving back towards the outer Solar System.
- A key feature that Rosetta's scientists are investigating is the way in which activity on the comet and the associated outgassing are driven, by monitoring the increasing activity on and around the comet since Rosetta's arrival.
- Scientists using Rosetta's Visible, InfraRed and Thermal Imaging Spectrometer, VIRTIS, have identified a region on the comet's surface where water ice appears and disappears in sync with its rotation period (Figure 126). Their findings are published in the journal Nature. The results are based on images and spectra taken at visible and infrared wavelengths of light on 12–14 September 2014 with VIRTIS. 178)
- The research team found a mechanism that replenishes the surface of the comet with fresh ice at every rotation: this keeps the comet 'alive'," says Maria Cristina De Sanctis from INAF-IAPS in Rome, Italy. The team studied a set of data taken in September 2014, concentrating on a 1 km2 region on the comet's neck. At the time, the comet was about 500 million km from the Sun and the neck was one of the most active areas. As the comet rotates, taking just over 12 hours to complete a full revolution, the various regions undergo different illumination. "We saw the tell-tale signature of water ice in the spectra of the study region but only when certain portions were cast in shadow," says Maria Cristina. "Conversely, when the Sun was shining on these regions, the ice was gone. This indicates a cyclical behavior of water ice during each comet rotation."
- The data suggest that water ice on and a few cm below the surface 'sublimates' when illuminated by sunlight, turning it into gas that then flows away from the comet. Then, as the comet rotates and the same region falls into darkness, the surface rapidly cools again. However, the underlying layers remain warm owing to the sunlight they received in the previous hours, and, as a result, subsurface water ice keeps sublimating and finding its way to the surface through the comet's porous interior. But as soon as this 'underground' water vapor reaches the cold surface, it freezes again, blanketing that patch of comet surface with a thin layer of fresh ice. - Eventually, as the Sun rises again over this part of the surface on the next comet day, the molecules in the newly formed ice layer are the first to sublimate and flow away from the comet, restarting the cycle.
- "We suspected such a water ice cycle might be at play at comets, on the basis of theoretical models and previous observations of other comets but now, thanks to Rosetta's extensive monitoring at 67P/Churyumov–Gerasimenko, we finally have observational proof," says Fabrizio Capaccioni, VIRTIS principal investigator at INAF-IAPS in Rome, Italy. From these data, it is possible to estimate the relative abundance of water ice with respect to other material. Down to a few cm deep over the region of the portion of the comet nucleus that was surveyed, water ice accounts for 10–15% of the material and appears to be well-mixed with the other constituents.
- The scientists also calculated how much water vapor was being emitted by the patch that they analyzed with VIRTIS, and showed that this accounted for about 3% of the total amount of water vapor coming out from the whole comet at the same time, as measured by Rosetta's MIRO microwave sensor. "It is possible that many patches across the surface were undergoing the same diurnal cycle, thus providing additional contributions to the overall outgassing of the comet," adds Fabrizio Capaccioni. The scientists are now busy analyzing VIRTIS data collected in the following months, as the comet's activity increased around the closest approach to the Sun.
Figure 126: The water-ice cycle of Rosetta's comet (image credit: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; M.C. De Sanctis et al (2015); Comet: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0)
- Left, top: Comet 67P/Churyumov-Gerasimenko based on four images taken by Rosetta's navigation camera on 2 September 2014.
- Left, bottom: images of Comet 67P/Churyumov–Gerasimenko taken with Rosetta's Visible, InfraRed and Thermal Imaging Spectrometer, VIRTIS (left), and maps of water ice abundance (middle) and surface temperature (right).
- The images were taken on 12 (top), 13 (middle) and 14 September (bottom) and focus on Hapi, a region on the comet's 'neck', one of the most active spots on the nucleus at the time.
- By comparing these images and maps, the scientists have found that water ice is present on colder patches, while it is less abundant or absent on warmer patches. In addition, water ice was only detected on a patch of the surface when it was cast in shadow. This indicates a cyclical behavior of water ice during each comet rotation.
- Right: the daily water ice cycle. During the local day, water ice on and a few centimeters below the surface sublimates and escapes; during the local night, the surface rapidly cools while the underlying layers are still warm, so subsurface water ice continues sublimating and finding its way to the surface, where it freezes again. On the next comet day, sublimation starts again, beginning from water ice in the newly formed surface layer.
• Sept. 15, 2015: New results from PTOLEMY – the OU (Open University) led instrument on the Rosetta mission’s Philae lander, suggest that Comet 67P/Churyumov-Gerasimenko may be giving of different gases from different parts of its surface, making it heterogeneous in nature. PTOLEMY – the gas analysis instrument on board Philae, has taken measurements of the concentration of volatile molecules at the lander’s final resting site, Abydos. Its findings have shown the presence of both water (H2O) and carbon dioxide (CO2), but of very little carbon monoxide (CO). These findings follow the first set of results published by the Ptolemy team last month which reported the presence of organic compounds in the surface dust on Comet 67P. 180) 181)
- The Ptolemy team have been surprised by the results as, based on the findings of the ROSINA instrument on board the Rosetta orbiter, they were expecting to see larger concentrations of CO on the surface. ROSINA, like PTOLEMY, is a mass spectrometer and at the time of landing was analyzing the gases rising from the surface some 30 km above Comet 67P. Results by ROSINA, acquired shortly before landing (published in January 2015), found that the concentration of CO, although variable, was up to four times that of CO2, whereas the PTOLEMY measurements found that CO was about ten times less than CO2.
- According to Andrew Morse, lead author on the paper, these findings could suggest that either the coma gas composition changes through various chemical reactions as it moves away from the comet, or that the gas vaporised from the comet varies by location, making it a heterogeneous comet. He says: “Though it is a possibility that carbon monoxide is produced in the coma as it moves away from the comet, a more probable account of such a large change would be that the gases released from the comet’s surface differs according to location.”
- One hypothesis is that a heterogeneous comet is the result of it being accumulated from diverse building blocks during its formation in the solar system. Alternatively it is the result of uneven heating in its journey into the inner solar system. The ROSINA instrument could help to answer this by making further measurements of the water coming off the comet’s surface. Andrew Morse adds: “Our results, from Comet 67P’s surface, has both surprised us as well as opened up a variety of new questions about how comets form and how they work. We’re eagerly awaiting new results which should help us to clarify whether Comet 67P is indeed heterogeneous in nature or if there is another explanation. Either way, these results offer up an important piece of the complex, yet fascinating puzzle of how comets are formed.”
- Co-author Geraint Morgan says: “The questions raised by PTOLEMY show the value of landers, even high risk ones, in establishing a ‘ground truth’ measurement on the surface to compare with on-going measurements from orbiting spacecraft. Despite Philae’s eventful journey, the data produced could be the key to help the Rosetta mission unlock the secrets of the Solar System.”
• August 13: 2015: ESA’s Rosetta today witnessed Comet 67P/Churyumov–Gerasimenko making its closest approach to the Sun. The exact moment of perihelion occurred at 02:03 GMT this morning when the comet came within 186 million km of the Sun. 182)
- In the year that has passed since Rosetta arrived, the comet has travelled some 750 million km along its orbit towards the Sun, the increasing solar radiation heating up the nucleus and causing its frozen ices to escape as gas and stream out into space at an ever greater rate. These gases, and the dust particles that they drag along, build up the comet’s atmosphere – coma – and tail.
- The activity reaches its peak intensity around perihelion and in the weeks that follow – and is clearly visible in the spectacular images returned by the spacecraft in the last months. One image taken by Rosetta’s navigation camera was acquired at 01:04 GMT, just an hour before the moment of perihelion, from a distance of around 327 km.
- The scientific camera is also taking images today – the most recent available image was taken at 23:31 GMT on 12 August, just a few hours before perihelion. The comet’s activity is clearly seen in the images, with a multitude of jets stemming from the nucleus, including one outburst captured in an image taken at 17:35 GMT yesterday.
Figure 127: This series of images of Comet 67P/Churyumov–Gerasimenko was captured by Rosetta’s OSIRIS narrow-angle camera on 12 August 2015, just a few hours before the comet reached the closest point to the Sun along its 6.5-year orbit, or perihelion (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Legend to Figure 127: The image at left was taken at 14:07 GMT, the middle image at 17:35 GMT, and the final image at 23:31 GMT. The images were taken from a distance of about 330 km from the comet. The comet’s activity, at its peak intensity around perihelion and in the weeks that follow, is clearly visible in these spectacular images. In particular, a significant outburst can be seen in the image captured at 17:35 GMT.
- “Activity will remain high like this for many weeks, and we’re certainly looking forward to seeing how many more jets and outburst events we catch in the act, as we have already witnessed in the last few weeks,” says Nicolas Altobelli, acting Rosetta project scientist.
- Rosetta’s measurements suggest the comet is spewing up to 300 kg of water vapor – roughly the equivalent of two bathtubs – every second. This is a thousand times more than was observed this time last year when Rosetta first approached the comet. Then, it recorded an outflow rate of just 300 g per second, equivalent to two small glasses of water.
- Along with gas, the nucleus is also estimated to be shedding up to 1000 kg of dust per second, creating dangerous working conditions for Rosetta.
• August 11, 2015: In the approach to perihelion over the past few weeks, Rosetta has been witnessing growing activity from Comet 67P/Churyumov–Gerasimenko, with one dramatic outburst event proving so powerful that it even pushed away the incoming solar wind . 183)
- The period around perihelion is scientifically very important, as the intensity of the sunlight increases and parts of the comet previously cast in years of darkness are flooded with sunlight. Although the comet’s general activity is expected to peak in the weeks following perihelion, much as the hottest days of summer usually come after the longest days, sudden and unpredictable outbursts can occur at any time – as already seen earlier in the mission.
- On 29 July, Rosetta observed the most dramatic outburst yet, registered by several of its instruments from their vantage point 186 km from the comet. They imaged the outburst erupting from the nucleus, witnessed a change in the structure and composition of the gaseous coma environment surrounding Rosetta, and detected increased levels of dust impacts (Figure 129). Perhaps most surprisingly, Rosetta found that the outburst had pushed away the solar wind magnetic field from around the nucleus.
- A sequence of images taken by Rosetta’s scientific camera OSIRIS show the sudden onset of a well-defined jet-like feature emerging from the side of the comet’s neck, in the Anuket region. It was first seen in an image taken at 13:24 GMT, but not in an image taken 18 minutes earlier, and has faded significantly in an image captured 18 minutes later. The camera team estimates the material in the jet to be travelling at 10 m/s at least, and perhaps much faster. “This is the brightest jet we’ve seen so far,” comments Carsten Güttler, OSIRIS team member at the MPS (Max Planck Institute for Solar System Research) in Göttingen, Germany.
- The decrease in magnetic field strength was measured by Rosetta’s RPC-MAG instrument during the outburst event on 29 July 2015. This is the first time a ‘diamagnetic cavity’ has been detected at Comet 67P/Churyumov–Gerasimenko and is thought to be caused by an outburst of gas temporarily increasing the gas flux in the comet’s coma, and pushing the pressure-balance boundary between it and incoming solar wind farther from the nucleus than expected under ‘normal’ levels of activity (Figure 128).
Figure 128: Discovery of diamagnetic cavity (image credit: ESA/Rosetta/RPC/IGEP/IC)
Figure 129: Rosetta’s scientific camera OSIRIS shows the sudden onset of a well-defined jet-like feature emerging from the side of the comet’s neck, in the Anuket region on July 29, 2015 (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
- Soon afterwards, the comet pressure sensor of ROSINA detected clear indications of changes in the structure of the coma, while its mass spectrometer recorded changes in the composition of outpouring gases. For example, compared to measurements made two days earlier, the amount of carbon dioxide increased by a factor of two, methane by four, and hydrogen sulphide by seven, while the amount of water stayed almost constant.
- During an outburst of gas and dust from Comet 67P/Churyumov–Gerasimenko on 29 July 2015, Rosetta’s ROSINA instrument detected a change in the composition of gases compared with previous days. Figure 130 shows the relative abundances of various gases after the outburst, compared with the measurements two days earlier. For example, the amount of carbon dioxide (CO2) increased by a factor of two, methane (CH4) by four, and hydrogen sulphide (H2S) by seven, while the amount of water (indicated by the horizontal black line) stayed almost constant.
Figure 130: Gas changes during 29 July outburst (image credit: ESA/Rosetta/ROSINA/UBern/ BIRA/LATMOS/LMM/IRAP/MPS/SwRI/TUB/UMich)
• August 10, 2015: What a difference a year can make. Rosetta arrived at Comet 67P/Churyumov–Gerasimenko on 6 August 2014, achieving rendezvous at a distance of 100 km before moving even closer to the nucleus in the following weeks. The image shown on the left was taken with the navigation camera, NAVCAM, on rendezvous day, when Rosetta was about 121 km out. 184)
Figure 131: Images of Comet 67P/Churyumov–Gerasimenko on 6 August 2014 (left) and on 6 August 2015 (right) with increased exposure to the Sun’s energy and its resulting activity (image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0)
• On August 6, 2015, ESA’s Rosetta mission celebrates one year at Comet 67P/Churyumov–Gerasimenko, with its closest approach to the Sun now just one week away. 185)
- It’s been a long but exciting journey for Rosetta since its launch in 2004, featuring Earth, Mars and two asteroid flybys before arriving at its ultimate destination on 6 August 2014. Over the following months, the mission became the first ever to orbit a comet and the first to soft land a probe – Philae – on its surface.
• July 30, 2015: Complex molecules that could be key building blocks of life, the daily rise and fall of temperature, and an assessment of the surface properties and internal structure of the comet are just some of the highlights of the first scientific analysis of the data returned by Rosetta's lander Philae last November. 186)
- Early results from Philae's first suite of scientific observations of Comet 67P/Churyumov-Gerasimenko were published today in a special edition of the journal Science (Science Special Issue, July 31, 2015). 187)
- Data were obtained during the lander's seven-hour descent to its first touchdown at the Agilkia landing site, which then triggered the start of a sequence of predefined experiments. But shortly after touchdown, it became apparent that Philae had rebounded and so a number of measurements were carried out as the lander took flight for an additional two hours some 100 m above the comet, before finally landing at Abydos.
- Meanwhile, Ptolemy sampled ambient gas entering tubes at the top of the lander and detected the main components of coma gases – water vapor, carbon monoxide and carbon dioxide, along with smaller amounts of carbon-bearing organic compounds, including formaldehyde.
- A timeline of the science operations that Rosetta's lander Philae performed between 12 and 15 November 2014, following touchdown on the surface of Comet 67P/Churyumov–Gerasimenko. This is an update on the original first science sequence. Following Philae's unexpected flight across the surface of the comet, the planned first science sequence had to be adapted according to the new situation. The graphic shows the approximate times (to the nearest 15 minutes) that each of Philae's 10 instruments was activated; however, it does not indicate the success of data acquired. 188)
Figure 132: Philae's adapted first science sequence (image credit: ESA)
• July 20, 2015: On 9 July 2015 at 19:45 CEST, Philae reported back to the team at DLR/LCC (Lander Control Center) only to then go back to 'silent mode'. Since then, the team has been working hard to get back in contact with the lander and operate it to conduct scientific measurements. "We sent a command to turn on the ROMAP (Rosetta Lander Magnetometer and Plasma Monitor), but have not seen a response," explains DLR's Philae project leader Stephan Ulamec. Using an identical model in the MUSC (Microgravity User Support Center) at DLR, the engineers are currently testing various commands, with which they want to enable and optimize Philae. "In the telemetry received, we have observed signs that Philae could have moved and that its antennas are thus perhaps more concealed or their orientation might have changed." 189)
Figure 133: Testing with the Philae lander ground model (image credit: DLR)
- Philae's move: In the data previously sent by Philae from the surface of Comet 67P/Churyumov-Gerasimenko about its condition, the lander has also transmitted information about the sunlight reaching its solar panels. “This profile – where panels are receiving a great deal of sunlight – has clearly changed between June and July,” says Ulamec. “This cannot be explained only by the course of the seasons on the comet.” The lander could have moved, for example, due to outgassing during the comet's awakening. After a not entirely smooth landing on 12 November 2014, Philae finally halted at a crater rim on uneven terrain – for this reason, even a slight change in its position could mean that its antennas are now obstructed by more objects above it. This would affect communication with Philae.
- Blind commands as backup: It is also possible that one of the lander's two radio receiver units is damaged and that one of the transmitter units is not fully functional. However, Philae is programmed to switch back and forth between the two transmitters periodically. This could also explain why contact with Philae is irregular. "We have therefore tested a command on our ground model that will cause Philae to only interact with the functional transmitter." This command has been transmitted to the lander. This 'blind commanding' – without the lander sending a confirmation – should make it possible for it to receive the command and execute it as soon as it is supplied with solar energy during the comet day and switches on.
- The engineers at the LCC are also testing another command on the ground model of Philae; they want to try to activate a 'work package' on the lander that was successfully executed in November 2014 during the landing and is still stored by Philae. At that time, the team at the LCC had supplied the lander with a kind of 'emergency program', so that it could still operate five instruments without communication. This occurred as the engineers at the consoles had to adjust their plans to adapt to the evolving situation with a new landing site. "With this work package, the thermal probe MUPUS measured temperatures, ROMAP and SESAME conducted measurements, and PTOLEMY and COSAC researched in 'sniff' mode," says Ulamec. "All of these instruments require no detailed commands, but the stored work package must first of all be retrieved." If this idea works, once Philae switches on, it would start to conduct scientific measurements and then send the data to Earth.
- Interaction between lander and orbiter: Until 24 July 2015, the Rosetta orbiter will fly an orbit that satisfies the requirements of the lander and follow a path that is favorable for communication between the two spacecraft. Then, Rosetta will fly with its 11 instruments over the southern hemisphere of the comet, which is now increasingly illuminated by the Sun. Here, the attempts to communicate with Philae will alternate with the priorities for observation with the orbiter instruments. The comet's increasing activity – with its gas and dust ejections –does not allow the orbiter to fly very close to the comet's surface. On 12 July 2015, Rosetta’s star trackers were once again affected by the dusty environment. For this reason, the orbiter is now flying at a safer distance of 170–190 km.
- Of course, the Philae lander team at DLR has not given up. "The lander is obviously still functional, because it sends us data, albeit at irregular intervals and at surprising times," says Ulamec. "There have been several times when we feared that the lander would not switch back on, but it has repeatedly taught us otherwise."
• July 13, 2015: Rosetta’s investigations of its comet are continuing as the mission teams count down the last month to perihelion – the closest point to the Sun along the comet’s orbit – when the comet’s activity is expected to be at its highest.“Perihelion is an important milestone in any comet’s calendar, and even more so for the Rosetta mission because this will be the first time a spacecraft has been following a comet from close quarters as it moves through this phase of its journey around the Solar System,” notes Matt Taylor, ESA’s Rosetta project scientist. “We’re looking forward to reaching perihelion, after which we’ll be continuing to monitor how the comet’s nucleus, activity and plasma environment changes in the year after, as part of our long-term studies.” 190)
Figure 134: The orbit of Comet 67P/Churyumov-Gerasimenko and its approximate location around perihelion, the closest the comet gets to the Sun. The positions of the planets are correct for 13 August 2015 (image credit: ESA)
• July 10, 2015: The Philae lander communicated with the Rosetta orbiter again between 19:45 and 20:07 CEST (Central European Standard Time) on 9 July 2015 and transmitted measurement data from the CONSERT (COmet Nucleus Sounding Experiment by Radiowave Transmission) instrument. Although the connection failed repeatedly after that, it remained completely stable for those 12 minutes. "This sign of life from Philae proves to us that at least one the lander's communication units remains operational and receives out commands," said German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) engineer Koen Geurts, a member of the lander control team at DLR Cologne. The mood had been mixed over the last few days; Philae had not communicated with the team in the DLR/LCC (Lander Control Center) since 24 June 2015. After an initial test command to turn on the power to CONSERT on 5 July 2015, the lander did not respond. Philae’s team began to wonder if the lander had survived on Comet 67P/Churyumov-Gerasimenko. 191)
- Commanded from the ground successfully: "We never gave up on Philae and remained optimistic," said Geurts. There was great excitement when Philae 'reported in' on 13 June 2015 after seven months of hibernation and sent data about its health. The lander was ready to perform its tasks, 300 million km away from Earth. However, Philae has to communicate with the ground stations through Rosetta, which acts as a radio relay. Restrictions on the orbiter's approach, orbiting around the comet, have not permitted regular communication with the lander. The data sent on 24 June did not suggest that the lander had experienced technical difficulties. Now, Philae's internal temperature of 0ºC gives the team hope that the lander can charge its batteries; this would make scientific work possible regardless of the 'time of day' on the comet.
- Currently, DLR's lander team is evaluating the data that were received. "We can already see that the CONSERT instrument was successfully activated by the command we sent on 9 July," explained Geurts. Even now, Philae is causing the team some puzzlement: "We do not yet have an explanation for why the lander has communicated now, but not over the past few days.” The trajectory of the orbiter, for example, has not changed over the last three weeks. However, one thing is certain; Philae has survived the harsh conditions on the comet and is responding to commands from the LCC team. "This is extremely good news for us," said Geurts.
• July 1, 2015: A number of the dust jets emerging from Rosetta’s comet can be traced back to active pits that were likely formed by a sudden collapse of the surface. These ‘sinkholes’ are providing a glimpse at the chaotic and diverse interior of the comet. 192)
- In a study reported in the science journal Nature, 18 quasi-circular pits have been identified in the northern hemisphere of the comet, some of which are the source of continuing activity. The pits are a few tens to a few hundreds of meters in diameter and extend up to 210 m below the surface to a smooth dust-covered floor. Material is seen to be streaming from the most active pits. The study team observes jets arising from the fractured areas of the walls inside the pits. These fractures mean that volatiles trapped under the surface can be warmed more easily and subsequently escape into space, according to Jean-Baptiste Vincent from the Max Planck Institute for Solar System Research, lead author of the study. 193)
Figure 135: Active pits on comet (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; graphic from J-B Vincent et al.)
Left: 18 pits have been identified in high-resolution OSIRIS images of Comet 67P/Churyumov–Gerasimenko’s northern hemisphere. The pits are named after the region they are found in, and some of them are active. The context image was taken on 3 August 2014 by the narrow-angle camera from a distance of 285 km; the image resolution is 5.3 m/pixel.
Middle, top: close-up of the active pit named Seth_01 reveals small jets emanating from the interior walls of the pit. The close-up also shows the complex internal structure of the comet. The image is a section of an OSIRIS wide-angle camera image capture on 20 October 2014 from a distance of 7 km from the comet surface. Seth_01 measures about 220 m across.
Right, top: context image showing fine structure in the comet’s jets as seen from a distance of 28 km from the comet’s surface on 22 November 2014. The image was taken with the OSIRIS wide-angle camera and has a resolution is 2.8 m/pixel. In both images the contrast is deliberately stretched in order to see the details of the activity. The active pits in this study contribute a small fraction of the observed activity.
Left, bottom: how the pits may form through sinkhole collapse. 1. Heat causes subsurface ices to sublimate (blue arrows), forming a cavity (2). When the ceiling becomes too weak to support its own weight, it collapses, creating a deep, circular pit (3, red arrow). Newly exposed material in the pit walls sublimates, accounting for the observed activity (3, blue arrows).
• June 26. 2015: Despite a new trajectory for Rosetta and a reduction of the distance between the orbiter and Comet 67P/Churyumov-Gerasimenko from 200 to 180 km, contact with the Philae lander remains irregular and short. After the initial contact on 13 June 2015, Philae has reported to the DLR/LCC (Lander Control Center) in Cologne a total of six times. However, for the last three possibilities calculated for establishing a connection with Philae, no data could be received. "Right now, we are playing with the geometry between the Rosetta orbiter and the Philae lander," says DLR's Philae Project Manager, Stephan Ulamec. "The most recent contact – on 24 June 2015 – lasted 20 minutes; then, the line went dead again." Now, the DLR and ESA mission teams are analyzing which measures will make better contact with Philae possible. 195)
- On June 27, ESA will begin new maneuvers, which will move the Rosetta orbiter 20 km closer to the comet's surface and Philae by 30 June 2015. The team at the DLR control center hopes that contact with Philae at a distance of 160 km will then be regular and stable. The next few days will show whether changes in the geometry between the lander and orbiter improves communication with Philae.
- One possible reason for the lander's current silence could be a failure of Philae's communications equipment caused by poor conditions during hibernation. Analysis of the data received so far by the team at DLR has shown that while one of the communications units is compromised, the other unit has worked thus far without problems. "To continue conducting scientific work with Philae, we rely on long and predictable contact times," says Ulamec. Once Philae can receive and execute extensive command sequences safely, store the measurement data and send it to the ground team, its 10 instruments will be operated again.
• June 24, 2015: Exposed water ice detected on Comet's surface. Using the high-resolution science OSIRIS camera on board ESA’s Rosetta spacecraft, scientists have identified more than a hundred patches of water ice a few meters in size on the surface of Comet 67P/Churyumov-Gerasimenko. A new study just published in the journal Astronomy & Astrophysics focuses on an analysis of bright patches of exposed ice on the comet’s surface. 196) 197)
- Based on observations of the gas emerging from comets, they are known to be rich in ices. As they move closer to the Sun along their orbits, their surfaces are warmed and the ices sublimate into gas, which streams away from the nucleus, dragging along dust particles embedded in the ice to form the coma and tail.
- But some of the comet’s dust also remains on the surface as the ice below sublimates, or falls back on to the nucleus elsewhere, coating it with a thin layer of dusty material and leaving very little ice directly exposed on the surface. These processes help to explain why Comet 67P/Churyumov-Gerasimenko and other comets seen in previous flyby missions are so dark.
- Despite this, Rosetta’s suite of instruments has already detected a variety of gases, including water vapor, carbon dioxide and carbon monoxide, thought to originate from frozen reservoirs below the surface.
- Now, using images taken with Rosetta’s OSIRIS narrow-angle camera last September, scientists have identified 120 regions on the surface of Comet 67P/Churyumov-Gerasimenko that are up to ten times brighter than the average surface brightness. Some of these bright features are found in clusters, while others appear isolated, and when observed at high resolution, many of them appear to be boulders displaying bright patches on their surfaces.
- The clusters of bright features, comprising a few tens of meter-sized boulders spread over several tens of meters, are typically found in debris fields at the base of cliffs. They are most likely the result of recent erosion or collapse of the cliff wall revealing fresher material from below the dust-covered surface.
- By contrast, some of the isolated bright objects are found in regions without any apparent relation to the surrounding terrain. These are thought to be objects lifted up from elsewhere on the comet during a period of cometary activity, but with insufficient velocity to escape the gravitational pull of the comet completely.
- In all cases, however, the bright patches were found in areas that receive relatively little solar energy, such as in the shadow of a cliff, and no significant changes were observed between images taken over a period of about a month. Furthermore, they were found to be bluer in color at visible wavelengths compared with the redder background, consistent with an icy component.
- “Water ice is the most plausible explanation for the occurrence and properties of these features,” says Antoine Pommerol of the University of Bern and lead author of the study. “At the time of our observations, the comet was far enough from the Sun such that the rate at which water ice would sublimate would have been less than 1 mm per hour of incident solar energy. By contrast, if carbon dioxide or carbon monoxide ice had been exposed, it would have rapidly sublimated when illuminated by the same amount of sunlight. Thus we would not expect to see that type of ice stable on the surface at this time.”
- The team also turned to laboratory experiments that tested the behavior of water ice mixed with different minerals under simulated solar illumination in order to gain more insights into the process. They found that after a few hours of sublimation, a dark dust mantle a few millimeters thick was formed. In some places this acted to completely conceal any visible traces of the ice below, but occasionally larger dust grains or chunks would lift from the surface and move elsewhere, exposing bright patches of water ice. “A 1 mm thick layer of dark dust is sufficient to hide the layers below from optical instruments,” confirms Holger Sierks, OSIRIS principal investigator at the Max Planck Institute for Solar System Research in Göttingen.
- The team also speculates about the timing of the formation of the icy patches. One hypothesis is that they were formed at the time of the last closest approach of the comet to the Sun, 6.5 years ago, with icy blocks ejected into permanently shadowed regions, preserving them for several years below the peak temperature needed for sublimation.
- Another idea is that even at relatively large distances from the Sun, carbon dioxide and carbon monoxide driven-activity could eject the icy blocks. In this scenario, it is assumed that the temperature was not yet high enough for water sublimation, such that the water-ice-rich components outlive any exposed carbon dioxide or carbon monoxide ice.
- “As the comet continues to approach perihelion, the increase in solar illumination onto the bright patches that were once in shadow should cause changes in their appearance, and we may expect to see new and even larger regions of exposed ice,” says Matt Taylor, ESA’s Rosetta project scientist. “Combining OSIRIS observations made pre- and post-perihelion with other instruments will provide valuable insight into what drives the formation and evolution of such regions.”
Figure 136: Ice on Comet 67P/Churyumov-Gerasimenko
• June 23, 2015: The adventure continues: ESA confirmed that its Rosetta mission will be extended until the end of September 2016, at which point the spacecraft will most likely be landed on the surface of Comet 67P/Churyumov-Gerasimenko.Rosetta’s nominal mission was originally funded until the end of December 2015, but at a meeting today, ESA’s Science Program Committee has given formal approval to continue the mission for an additional nine months. At that point, as the comet moves far away from the Sun again, there will no longer be enough solar power to run Rosetta’s set of scientific instrumentation efficiently. 198)
- “This is fantastic news for science,” says Matt Taylor, ESA’s Rosetta Project Scientist. “We’ll be able to monitor the decline in the comet’s activity as we move away from the Sun again, and we’ll have the opportunity to fly closer to the comet to continue collecting more unique data. By comparing detailed ‘before and after’ data, we’ll have a much better understanding of how comets evolve during their lifetimes.”
- Comet 67P/Churyumov-Gerasimenko will make its closest approach to the Sun on 13 August and Rosetta has been watching its activity increase over the last year. Continuing its study of the comet in the year following perihelion will give scientists a fuller picture of how a comet’s activity waxes and wanes along its orbit.
- As the activity diminishes post-perihelion, it should be possible to move the orbiter much closer to the comet’s nucleus again, to make a detailed survey of changes in the comet’s properties during its brief ‘summer’. In addition, there may be an opportunity to make a definitive visual identification of Philae. Although candidates have been seen in images acquired from a distance of 20 km, images taken from 10 km or less after perihelion could provide the most compelling confirmation.
- During the extended mission, the team will use the experience gained in operating Rosetta in the challenging cometary environment to carry out some new and potentially slightly riskier investigations, including flights across the night-side of the comet to observe the plasma, dust, and gas interactions in this region, and to collect dust samples ejected close to the nucleus.
- As the comet recedes from the Sun, the solar-powered spacecraft will no longer receive enough sunlight to operate efficiently and safely, equivalent to the situation in June 2011 when the spacecraft was put into hibernation for 31 months for the most distant leg of its journey out towards the orbit of Jupiter.
Figure 137: A Rosetta NAVCAM camera single frame image of Comet 67P/Churyumov-Gerasimenko, acquired on 5 June 2015 from a distance of 208 km from the comet center. The image has a resolution of 17.7 m/pixel and measures 18.1 km across (image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0)
• June 19, 2015: The DLR team received data from the Philae lander for the third time on 19 June 2015. Between 13:20 and 13:39 UTC, Philae sent 185 data packets. "Among other things, we have received updated status information," says Michael Maibaum, a systems engineer at the DLR (Lander Control Center) in Cologne and Deputy Operations Manager. "At present, the lander is operating at a temperature of zero degrees Celsius, which means that the battery is now warm enough to store energy. This suggests that Philae will also be able to work during the comet's night, regardless of solar illumination." In the 19 minutes of transmission, the lander sent data recorded last week; from this, the engineers determined that the amount of sunlight has increased: "More solar panels were illuminated; at the end of contact, four of Philae's panels were receiving energy". There were a number of interruptions in the connection, but it was otherwise stable over a longer period for the first time. “The contact has confirmed that Philae is doing very well.” 199)
Figure 138: Photo of the LLC (Lander Control Center) at DLR (image credit: DLR)
• June 15, 2015: The receipt of signals from Rosetta's Philae lander on 13 June after 211 days of hibernation marked the start of intense activity. In coordination with its mission partners, ESA teams are working to juggle Rosetta's flight plan to help with renewed lander science investigations. 200)
- Since March 2015, when Philae's environmental conditions started to improve with higher surface temperatures and better illumination, the orbiter's receiver had been turned on periodically to listen for signals from the lander when the orbital geometry was thought to be optimum. On the evening of 13 June, a weak but solid radio link between Rosetta and the lander was finally established for 85 seconds. More than 300 'packets' (663 kbit) of lander housekeeping telemetry were received. This information had been stored on board at an as-yet-to-be determined time in the past, as much as several days to a few weeks, so does not necessarily reflect the lander's current status.
- "We are still examining the housekeeping information at the Lander Control Center in the DLR German Aerospace Center's establishment in Cologne, but we can already tell that all lander subsystems are working nominally, with no apparent degradation after more than half a year hiding out on the comet's frozen surface," says DLR's Stephan Ulamec, Philae Lander Project Manager.
- A second, smaller burst of lander data was received on Sunday, 14 June, at about 21:26 UTC, lasting just a few seconds. These data were confirmed to give the current status, showing the lander's internal temperature had already risen to –5ºC.
- Engineers at the Lander Control Center have determined that Philae is already being exposed to sufficient sunlight to heat it to an acceptable operating temperature and to generate electricity.
- "Power levels increase during the local 'comet day' – the part of the about-12 hour comet rotation when Philae is in sunlight – from 13 W at comet sunrise to above 24 W," notes ESA's Patrick Martin, Rosetta Mission Manager. "It needs at least 19 W to switch on the transmitter."
- The telemetry downloaded covered the lander's status for a full night–day cycle of the comet, which is helping ground teams to understand how the Sun is shining on the lander. The solar panels appear to be receiving power for over 135 minutes in each illumination period.
- The main task now for all the mission partners — ESA for Rosetta operations and DLR and France's CNES space agency for lander operations and science, respectively — is to determine how to optimize Rosetta's orbit so as to facilitate contact and enable new science investigations. It is believed that there is sufficient power now being generated to allow some science measurements during the time Philae is illuminated, with initial activities focusing on low-power measurements. This first phase would also likely include measurements that did not previously generate science in November.
- However, the mission teams first must establish a more robust link between Rosetta and Philae before uploading the first batch of science operations commands. The quality of the communication link is also possibly related to the trajectory Rosetta is flying and the orientation it adopts.
- Optimizing an orbit 305 million km away: Currently, Rosetta experiences two possible communication slots per 24 hours – once per 12-hour comet rotation. Until 23:35 UTC on Tuesday, 16 June, Rosetta will be flying an orbit set by already-uploaded commands on the terminator – the plane between comet day and night – moving out from about 200 km to 235 km altitude.
- This orbit is not optimized for lander communication, so longer periods of contact may not be possible until the trajectory has been changed. "With work done by the flight dynamics and operations team at ESOC and based on intense planning being conducted with the mission partners today, a new orbit will be devised that ensures optimum lander communications beginning with the next command upload later tonight," says Paolo Ferri, ESA's Head of Mission Operations.
- This new orbit will include an already-planned reduction of distance from the nucleus, down to 180 km versus 200 km, and 'nadir pointing' – continuously pointing Rosetta's communications unit at the comet. In the coming days, the orbiter may also be moved closer to the comet, without compromising the safety of the spacecraft, to help communications.
- The new orbit will be flown by Rosetta starting after 23:25 UTC on 16 June until 19 June, aiming to enable more and longer contacts with Philae, especially towards the end of this period. Establishing a regular and predictable pattern of contacts is a prerequisite for performing a complete assessment of the lander's status and for planning science operations. "If we manage to achieve and maintain a predictable contact pattern," continues Paolo Ferri, "the lander teams can devise a strategy for a new sequence of scientific operations.
- As a bonus, any operation of Philae's instruments up to or through perihelion on 13 August – the comet's closest point to the Sun along its orbit – will allow in-situ study of a comet during its peak activity.
• The Philae lander has reported back on 13 June 2015 at 20:28 (UTC), coming out of hibernation and sending the first data to Earth. More than 300 data packets have been analyzed by the team at the DLR ( German Aerospace Center) Lander Control Center: "Philae is doing very well – it has an operating temperature of minus 35º Celsius and has 24 W of power available," explains DLR’s Philae Project Manager, Stephan Ulamec. "The lander is ready for operations." Philae 'spoke' for 85 seconds with its team on ground in its first contact since it went into hibernation. The signals were also received at ESA/ESOC in Darmstadt, Germany. 201) 202)
- When analyzing the status data, it became clear that Philae also must have been awake earlier: "We have also received historical data – until now, however, the lander had not been able to contact us. "Now, the scientists are waiting for the next contact. In Philae's mass memory, there are still more than 8000 data packets, which will give the DLR team information on what happened to Philae in the past few days on comet Churyumov-Gerasimenko.
- Philae shut down on 15 November 2014 at 02:15 UTC, after being in operation on the comet for about 60 hours. Since 12 March 2015, the communication unit on the Rosetta orbiter has repeatedly been turned on to communicate with the lander and receive its reply.
• June 2, 2015: Rosetta's continued close study of Comet 67P/Churyumov–Gerasimenko has revealed an unexpected process at work, causing the rapid breakup of water and carbon dioxide molecules spewing from the comet’s surface. - One instrument, the Alice spectrograph provided by NASA, has been examining the chemical composition of the comet's atmosphere, or coma, at far-ultraviolet wavelengths. At these wavelengths, Alice allows scientists to detect some of the most abundant elements in the Universe such as hydrogen, oxygen, carbon and nitrogen. The spectrograph splits the comet's light into its various colors – its spectrum – from which scientists can identify the chemical composition of the coma gases. 203) 204)
- In a study, scientists from several institutions report the detections made by Alice from Rosetta’s first four months at the comet, when the spacecraft was between 10 km and 80 km from the center of the comet nucleus. The research team focused on the nature of 'plumes' of water and carbon dioxide gas erupting from the comet's surface, triggered by the warmth of the Sun. To do so, they looked at the emission from hydrogen and oxygen atoms resulting from broken water molecules, and similarly carbon atoms from carbon dioxide molecules, close to the comet nucleus. They discovered that the molecules seem to be broken up in a two-step process. 205)
- First, an ultraviolet photon from the Sun hits a water molecule in the comet’s coma and ionizes it, knocking out an energetic electron. This electron then hits another water molecule in the coma, breaking it apart into two hydrogen atoms and one oxygen, and energizing them in the process. These atoms then emit ultraviolet light that is detected at characteristic wavelengths by Alice.
- Similarly, it is the impact of an electron with a carbon dioxide molecule that results in its break-up into atoms and the observed carbon emissions. "Analysis of the relative intensities of observed atomic emissions allows us to determine that we are directly observing the ‘parent’ molecules that are being broken up by electrons in the immediate vicinity, about 1 km, of the comet’s nucleus where they are being produced," says Paul Feldman, professor of physics and astronomy at the Johns Hopkins University in Baltimore, and lead author of the paper discussing the results.
- By comparison, from Earth or from Earth-orbiting space observatories such as the Hubble Space Telescope, the atomic constituents of comets can only be seen after their parent molecules, such as water and carbon dioxide, have been broken up by sunlight, hundreds to thousands of kilometers away from the nucleus of the comet. "The discovery we’re reporting is quite unexpected," says Alice Principal Investigator Alan Stern, an associate vice-president in the Space Science and Engineering Division of the Southwest Research Institute (SwRI). "It shows us the value of going to comets to observe them up close, since this discovery simply could not have been made from Earth or Earth orbit with any existing or planned observatory. And, it is fundamentally transforming our knowledge of comets."
- The results from Alice are supported by data obtained by other Rosetta instruments, in particular MIRO, ROSINA and VIRTIS, which are able to study the abundance of different coma constituents and their variation over time, and particle detecting instruments like RPC-IES. "These early results from Alice demonstrate how important it is to study a comet at different wavelengths and with different techniques, in order to probe various aspects of the comet environment," says ESA’s Rosetta project scientist Matt Taylor. "We’re actively watching how the comet evolves as it moves closer to the Sun along its orbit towards perihelion in August, seeing how the plumes become more active due to solar heating, and studying the effects of the comet’s interaction with the solar wind."
- Studying the properties of a comet can provide clues to the role that magnetic fields played in the formation of Solar System bodies almost 4.6 billion years ago. The infant Solar System was once nothing more than a swirling disc of gas and dust but, within a few million years, the Sun burst into life in the center of this turbulent disc, with the leftover material going into forming the asteroids, comets, moons and planets. — The dust contained an appreciable fraction of iron, some of it in the form of magnetite. Indeed, millimeter-sized grains of magnetic materials have been found in meteorites, indicating their presence in the early Solar System.
Figure 139: Rosetta and Philae investigate magnetic properties of Comet 67P/C-G (image credit: ESA)
- This leads scientists to believe that magnetic fields threading through the proto-planetary disc could have played an important role in moving material around as it started to clump together to form larger bodies. But it remains unclear as to how crucial magnetic fields were later on in this accretion process, as the building blocks grew to centimeters, meters and then tens of meters across, before gravity started to dominate when they grew to hundreds of meters and kilometers in scale. Some theories concerning the aggregation of magnetic and non-magnetic dust particles show that the resulting bigger objects could also remain magnetised, allowing them to also be influenced by the magnetic fields of the proto-planetary disc.
- Because comets contain some of the most pristine materials in the Solar System, they offer a natural laboratory for investigating whether or not these larger chunks could have remained magnetized. However, detecting the magnetic field of comets has proven difficult in previous missions, which have typically made rapid flybys, relatively far from comet nuclei. — It has taken the proximity of ESA’s Rosetta orbiter to Comet 67P/Churyumov-Gerasimenko, and the measurements made much closer to and at the surface by its lander Philae, to provide the first detailed investigation of the magnetic properties of a comet nucleus.
• Reconstructing Philae’s trajectory: Magnetic field data from ROMAP on Philae, combined with information from the CONSERT experiment that provided an estimate of the final landing region, timing information, images from Rosetta’s OSIRIS camera, assumptions about the gravity of the comet, and measurements of its shape, have been used to reconstruct the trajectory of the lander during its descent and subsequent landings on and bounces over the surface of Comet 67P/Churyumov-Gerasimenko on 12 November 2014. The times are as recorded by the spacecraft; the confirmation signals arrived on Earth 28 minutes later. 208)
- Initially, Philae was seen to rotate slowly during the descent to Agilkia. It landed and then bounced, rotating significantly faster as the momentum of the internal flywheel was transferred to the lander. It collided with a cliff 45 minutes later, then tumbled, flying above the surface for more than an hour longer, before bouncing once again and coming to a stop a few meters away, a few minutes later.
- The position of the first touchdown point at Agilkia is very well determined from direct images, but the locations of the possible cliff collision depends on the ballistic model used, while the general location marked for the subsequent second and third touchdowns at Abydos come from the CONSERT measurements. Thus, these latter positions represent preliminary and approximate locations only. - The heights above the surface assume a reference sphere centered on the center of mass of the comet and with a radius of 2393 m reaching first touchdown point.
Figure 140: Reconstructing Philae's trajectory across Comet 67P/Churyumov-Gerasimenko (ESA/Data: Auster et al. (2015)/Comet image: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
- Philae’s magnetic field measuring instrument is the ROMAP (Rosetta Lander Magnetometer and Plasma Monitor), while Rosetta carries a magnetometer as part of the RPC-MAP (Rosetta Plasma Consortium suite of sensors). Changes in the magnetic field surrounding Rosetta allowed RPC-MAG to detect the moment when Philae was deployed in the morning of 12 November 2014.
- Then, by sensing periodic variations in the measured external magnetic field and motions in its boom arm, ROMAP was able to detect the touchdown events and determine the orientation of Philae over the following hours. Combined with information from the CONSERT experiment that provided an estimate of the final landing site location, timing information, images from Rosetta’s OSIRIS camera, assumptions about the gravity of the comet, and measurements of its shape, it was possible to determine Philae’s trajectory.
- The mission teams soon discovered that Philae not only touched down once at Agilkia, but also came into contact with the comet’s surface four times in fact – including a grazing collision with a surface feature that sent it tumbling towards the final touchdown point at Abydos. This complex trajectory turned out to be scientifically beneficial to the ROMAP team.
- “The unplanned flight across the surface actually meant we could collect precise magnetic field measurements with Philae at the four points we made contact with, and at a range of heights above the surface,” says Hans-Ulrich Auster, co-principal investigator of ROMAP and lead author of the results published in the journal Science and presented at the European Geosciences Union General Assembly in Vienna, Austria (April 12-17, 2015). 209)
- The multiple descents and ascents meant that the team could compare measurements made on the inward and outward journeys to and from each contact point, and as it flew across the surface. ROMAP measured a magnetic field during these sequences, but found that its strength did not depend on the height or location of Philae above the surface. This is not consistent with the nucleus itself being responsible for that field.
- “If the surface was magnetized, we would have expected to see a clear increase in the magnetic field readings as we got closer and closer to the surface,” explains Hans-Ulrich. “But this was not the case at any of the locations we visited, so we conclude that Comet 67P/Churyumov-Gerasimenko is a remarkably non-magnetic object.”
- Instead, the magnetic field that was measured was consistent with an external one, namely the influence of the solar wind interplanetary magnetic field near the comet nucleus. This conclusion is confirmed by the fact that variations in the field that were measured by Philae closely agree with those seen at the same time by Rosetta.
- “During Philae’s landing, Rosetta was about 17 km above the surface, and we could provide complementary magnetic field readings that rule out any local magnetic anomalies in the comet’s surface materials,” says Karl-Heinz Glassmeier, principal investigator of RPC-MAG on board the orbiter and a co-author of the Science paper.
- If large chunks of material on the surface of 67P/Churyumov-Gerasimenko were magnetized, ROMAP would have recorded additional variations in its signal as Philae flew over them. “If any material is magnetized, it must be on a scale of less than one meter, below the spatial resolution of our measurements. And if Comet 67P/Churyumov-Gerasimenko is representative of all cometary nuclei, then we suggest that magnetic forces are unlikely to have played a role in the accumulation of planetary building blocks greater than one meter in size,” concludes Hans-Ulrich.
- “It’s great to see the complementary nature of Rosetta and Philae’s measurements, working together to answer this simple, but important ‘yes-no’ question as to whether the comet is magnetized,” says Matt Taylor, ESA’s Rosetta project scientist.
Figure 141: Philae's magnetic field measurements before and after surface collision (Comet: ESA/Rosetta/NAVCAM-CC BY-SA IGO 3.0; Data from Auster et al. (2015)
Legend to Figure 141: Magnetic field data collected by Philae’s ROMAP instrument immediately before (top) and after (bottom) the cliff collision at 16:20 GMT on 12 November 2014 (onboard spacecraft time), between the first and second touchdowns. Height above the surface is plotted on the x-axis and magnetic field strength on the y-axis. Therefore time runs left-to-right for the ascent (lower) plot, but right-to-left for the descent (upper) plot.
The measurements (crosses) are compared with a hypothetical model (solid line) assuming a slightly magnetized surface. Also included is the strength of and variation in the external field, namely the influence of the solar wind interplanetary magnetic field near the comet nucleus.
At distances of 10 m or greater from the surface, the surface component would be very weak, leaving just the external field, as measured. But closer to the surface, the comet’s own field should increase and dominate. That is not seen, therefore the data suggest that at scales of greater than one meter (the resolution of the instrument), the comet is not magnetized.
• April 13, 2015: Four months from today, on 13 August, Comet 67P/Churyumov-Gerasimenko will reach perihelion – a moment that defines its closest point to the Sun along its orbit. For 67P/Churyumov-Gerasimenko, this takes place at a distance of about 185 million km from the Sun, between the orbits of Earth and Mars. The Rosetta spacecraft is along for the ride, and has been watching the gradual evolution of the comet since arriving in August 2014. 210)
- As the comet’s surface layers are gently warmed, frozen ices sublimate. The escaping gas carries streams of dust out into space, and together these slowly expand to create the comet’s fuzzy atmosphere, or coma. — As the comet continues to move closer to the Sun, the warming continues and activity rises, and pressure from the solar wind causes some of the materials to stream out into long tails, one made of gas, the other of dust. The comet’s coma will eventually span tens of thousands of kilometers, while the tails may extend hundreds of thousands of kilometers, and both will be visible through large telescopes on Earth.
- But it is Rosetta’s close study of the comet, from just a few tens of kilometers above its surface, which enables the source of the comet’s activity to be studied in great detail, providing context to the more distant ground-based observations.
- This spectacular montage of 18 images (Figure 142) shows off the comet’s activity from many different angles as seen between 31 January (top left) and 25 March (bottom right), when the spacecraft was at distances of about 30 to 100 km from the comet. At the same time, Comet 67P/Churyumov-Gerasimenko was at distances between 363 million and 300 million km from the Sun. — After perihelion, Rosetta will continue to follow the comet, watching how the activity subsides as it moves away from the Sun and back to the outer Solar System again.
- This leads scientists to believe that magnetic fields threading through the proto-planetary disc could have played an important role in moving material around as it started to clump together to form larger bodies.
Figure 142: Comet activity 31 January – 25 March 2015 (ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0)
• March 20, 2015: Perhaps it is still too cold for the Philae lander to wake up on Comet 67P/Churyumov-Gerasimenko. Maybe its power resources are not yet sufficient to send a signal to the team at DLR (German Aerospace Center) Lander Control Center. On 12 March 2015, the Rosetta orbiter began to send signals to the lander and listen for a response, but Philae has not yet reported back. "It was a very early attempt; we will repeat this process until we receive a response from Philae," says DLR Project Manager Stephan Ulamec. "We have to be patient." On 20 March 2015 at 05:00 CET (Central European Time), the communication unit on the Rosetta orbiter was switched off. Now, the DLR team is calculating when the next favorable alignment between the orbiter and the lander will occur, and will then listen again for a signal from Philae. The next chance to receive a signal from the lander is expected to occur during the first half of April. 211)
• March 19, 2015: ESA’s Rosetta spacecraft has made the first measurement of molecular nitrogen at a comet, providing clues about the temperature environment in which Comet 67P/Churyumov–Gerasimenko formed. The in situ detection of molecular nitrogen has long been sought at a comet. Nitrogen had only previously been detected bound up in other compounds, including hydrogen cyanide and ammonia, for example. 212)
- Its detection is particularly important since molecular nitrogen is thought to have been the most common type of nitrogen available when the Solar System was forming. In the colder outer regions, it likely provided the main source of nitrogen that was incorporated into the gas planets. It also dominates the dense atmosphere of Saturn’s moon, Titan, and is present in the atmospheres and surface ices on Pluto and Neptune’s moon Triton.
Figure 143: First detection of molecular nitrogen at a comet (image credit: ESA/ATG medialab; comet: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0; Data: Rubin et al.)
Legend to Figure 143: The graph shows the variation in the signals measured for molecular nitrogen (N2) and carbon monoxide (CO) by Rosetta’s ROSINA instrument. The signals vary as a function of time, comet rotation and position of the spacecraft above the comet. An average ratio of N2/CO = (5.70 ± 0.66) x 10–3 was determined for the period 17–23 October 2014. The minimum and maximum values measured were 1.7 x 10–3 and 1.6 x 10–2, respectively (note that the ratio cannot be derived directly from this graph – a correction factor accounting for the instrument sensitivity is applied).
By comparing the ratio of N2 to CO at the comet with that of the protosolar nebula, it was determined that the comet must have formed at low temperatures, consistent with a Kuiper Belt origin. The study also finds that Jupiter-family comets like Comet 67P/ Churyumov–Gerasimenko were unlikely the source of Earth’s nitrogen.
• On March 4, 2015, ESA posted the four NAVCAM images of Figure 144 from distances of 80-100 km, to show the current activity of the comet. While most of Rosetta’s NAVCAM images are taken for navigation purposes, these images were obtained to provide context in support of observations performed at the same time with the Alice ultraviolet (UV) imaging spectrograph on Rosetta. The four images show the nucleus at different orientations, providing a good overview of the comet’s activity over the time interval between 25 and 27 February 2015. 213)
Figure 144: Montage of four single-frame images of Comet 67P/C-G taken by Rosetta’s Navigation Camera (NAVCAM) on Feb.25 (top left), Feb. 26, (top right) and the two bottom pictures on Feb. 27, 2015. The images have been processed to bring out the details of the comet’s activity. The exposure time for each image is 2 s (image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0)
• March 3, 2015: Images from the OSIRIS scientific imaging camera taken during the close flyby on February 14, 2015 have now been downlinked to Earth, revealing the surface of Comet 67P/C-G in unprecedented detail, and including the shadow of the spacecraft encircled in a wreath of light. During the flyby, Rosetta not only passed closer by the comet than ever before, but also passed through a unique observational geometry: for a short time the Sun, spacecraft, and comet were exactly aligned. In this geometry, surface structures cast almost no shadows, and therefore the reflection properties of the surface material can be discerned. 214)
Figure 145: Comet flyby: OSIRIS catches glimpse of Rosetta’s shadow (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Legend to Figure 145: Close-up view of a 228 x 228 m region on Comet 67P/Churyumov-Gerasimenko, as seen by the OSIRIS narrow-angle camera during Rosetta’s flyby at 12:39 UTC on 14 February 2015. The image was taken 6 km above the comet’s surface, and the image resolution is just 11 cm/pixel. Rosetta’s fuzzy shadow, measuring approximately 20 x 50 m, is seen at the bottom of the image.
• Feb. 17, 2015: The spacecraft is no longer orbiting the comet, it is now performing a series of flybys to continue its science. 215)
- The video of Ref. 215) explains the next stage of the Rosetta mission, the science that will be done during 2015 by the orbiter’s flybys, and assesses the possibility of the Philae lander’s reactivation from hibernation. So far Rosetta has only mapped about seventy percent of the surface because the comet’s orbit and rotation kept certain areas in darkness. — This year new regions will come into view alongside new activity on the surface. When the comet is at the peak of its activity in the summer, Rosetta’s instruments will be there to observe, measure and record a spectacular event.
• On 14 February 2015, Rosetta swooped over the surface of Comet 67P/Churyumov–Gerasimenko at a distance of just 6 km. The closest approach took place at 12:41 GMT over a region known as Imhotep, which is on the larger of the comet’s two lobes. 216)
- The image of Figure 146 reveals the contrasting terrains seen on this comet. Layered and fractured exposed surfaces contrast against expanses of smooth, dust-covered terrain. In some places, such as to the lower right of this image, the faint outline of raised near-circular objects with smooth surfaces can be seen. Elsewhere, boulders ranging in size from a few meters to a few tens of meters are scattered across the surface. The largest boulder, seen to the upper right, is named Cheops.
Figure 146: The surface of Comet 67P/C acquired on 14 February with NavCam from 8.7 km (image credit: ESA/Rosetta/NavCam, CC BY-SA IGO 3.0)
• January 26, 2015: ESA's Rosetta mission is providing unique insight into the life cycle of a comet's dusty surface, watching 67P/Churyumov-Gerasimenko as it sheds the dusty coat it has accumulated over the past four years. 217)
- The COSIMA (COmetary Secondary Ion Mass Analyzer) instrument is one of Rosetta's three dust analysis experiments. It started collecting, imaging and measuring the composition of dust particles shortly after the spacecraft arrived at the comet in August 2014.
- Results from the first analysis of its data are reported in the journal Nature on January 26, 2015. The study covers August to October, when the comet moved along its orbit between about 535 million km to 450 million km from the Sun. Rosetta spent most of this time orbiting the comet at distances of 30 km or less. 218)
Figure 147: Dust grains from comet 67P/Churyumov-Gerasimenko (image credit: ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S)
Legend to Figure 147: Two examples of dust grains were collected by the COSIMA instrument in the period 25-31 October 2014. Both grains were collected at a distance of 10-20 km from the comet nucleus. Image (a) shows a dust particle,named by the COSIMA team as Eloi, that crumbled into a rubble pile when collected; (b) shows a dust particle that shattered, named Arvid.
For both grains, the image is shown twice under two different grazing illumination conditions: the top image is illuminated from the right, the bottom image from the left. The brightness is adjusted to emphasize the shadows, in order to determine the height of the dust grain. Eloi therefore reaches about 0.1 mm above the target plate; Arvid about 0.06 mm. The two small grains at the far right of image (b) are not part of the shattered cluster.
The fact that the grains broke apart so easily means their individual parts are not well glued together. If they contained ice they would not shatter; instead, the icy component would evaporate off the grain shortly after touching the collecting plate, leaving voids in what remained. By comparison, if a pure water-ice grain had struck the detector, then only a dark patch would have been seen.
These 'fluffy' grains are thought to originate from the dusty layer built up on the comet's surface since its last close approach to the Sun, and will soon be lost into the coma.
- The scientists looked at the way that many large dust grains broke apart when they were collected on the instrument's target plate, typically at low speeds of 1-10 m/s. The grains, which were originally at least 0.05 mm across, fragmented or shattered upon collection. — The fact that they broke apart so easily means that the individual parts were not well bound together. Moreover, if they had contained ice, they would not have shattered. Instead, the icy component would have evaporated off the grain shortly after touching the collecting plate, leaving voids in what remained.
• January 22, 2015: Rosetta is revealing its host comet as having a remarkable array of surface features and with many processes contributing to its activity, painting a complex picture of its evolution. In a special edition of the journal Science, initial results are presented from seven of Rosetta's 11 science instruments based on measurements made during the approach to and soon after arriving at Comet 67P/Churyumov–Gerasimenko in August 2014. 219)
- The familiar shape of the dual-lobed comet has now had many of its vital statistics measured: the small lobe measures 2.6 x 2.3 x 1.8 km and the large lobe 4.1 x 3.3 x 1.8 km. The total volume of the comet is 21.4 km3 and the Radio Science Instrument has measured its mass to be 10 billion tons, yielding a density of 470 kg/m3.
- By assuming an overall composition dominated by water ice and dust with a density of 1500-2000 kg/m3, the Rosetta scientists show that the comet has a very high porosity of 70-80%, with the interior structure likely comprising weakly bonded ice-dust clumps with small void spaces between them.
Figure 148: Comet regional maps (image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)
Legend to Figure 148: The 19 regions identified on Comet 67P/Churyumov–Gerasimenko are separated by distinct geomorphological boundaries. Following the ancient Egyptian theme of the Rosetta mission, they are named for Egyptian deities. They are grouped according to the type of terrain dominant within each region. Five basic categories of terrain type have been determined: dust-covered (Ma’at, Ash and Babi); brittle materials with pits and circular structures (Seth); large-scale depressions (Hatmehit, Nut and Aten); smooth terrains (Hapi, Imhotep and Anubis), and exposed, more consolidated (‘rock-like’) surfaces (Maftet, Bastet, Serqet, Hathor, Anuket, Khepry, Aker, Atum and Apis).
- The OSIRIS scientific camera, has imaged some 70% of the surface to date: the remaining unseen area lies in the southern hemisphere that has not yet been fully illuminated since Rosetta’s arrival.
- Much of the northern hemisphere is covered in dust. As the comet is heated, ice turns directly into gas that escapes to form the atmosphere or coma. Dust is dragged along with the gas at slower speeds, and particles that are not travelling fast enough to overcome the weak gravity fall back to the surface instead.
Figure 149: Summary of the comet's vital statistics as determined by Rosetta’s instruments during the first few months of its comet encounter (image credit: ESA)
The full range of values are presented and discussed in a series of papers published in the 23 January 2015 issue of the journal Science, Vol, 347, Issue 6220 (http://www.sciencemag.org/content/347/6220.toc#SpecialIssue). The following papers are listed:
1) H. Sierks, C. Barbieri, P. L. Lamy, et al., “On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko.”
2) A. Rotundi, H. Sierks, V. Della Corte, et al., “Dust measurements in the coma of comet 67P/Churyumov-Gerasimenko inbound to the Sun.”
3) F. Capaccioni, A. Coradini, G. Filacchione, et al., “The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta.”
4) H. Nilsson, G. Stenberg-Wieser, E. Behar, “Birth of a comet magnetosphere: A spring of water ions.”
5) N. Thomas, H. Sierks, C. Barbieri, et al., “The morphological diversity of comet 67P/ Churyumov-Gerasimenko.”
6) K. Altwegg, H. Balsiger, A. Bar-Nun, et al., “67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio.”
7) M. Hässig, K. Altwegg, H. Balsiger, et al., “Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko.”
8) S. Gulkis, M. Allen, P. von
Allmen, et al., “Subsurface properties and early activity of
• Dec. 10, 2014: ESA’s Rosetta spacecraft has found the water vapor from its target comet to be significantly different to that found on Earth. The discovery fuels the debate on the origin of our planet’s oceans. The measurements were made in the month following the spacecraft’s arrival at Comet 67P/Churyumov–Gerasimenko on 6 August. It is one of the most anticipated early results of the mission, because the origin of Earth’s water is still an open question. 220) 221) 222) 223)
- One of the leading hypotheses on Earth’s formation is that it was so hot when it formed 4.6 billion years ago that any original water content should have boiled off. But, today, two thirds of the surface is covered in water, so where did it come from? In this scenario, it should have been delivered after our planet had cooled down, most likely from collisions with comets and asteroids. The relative contribution of each class of object to our planet’s water supply is, however, still debated.
- The key to determining where the water originated is in its ‘flavor’, in this case the proportion of deuterium – a form of hydrogen with an additional neutron – to normal hydrogen. This proportion is an important indicator of the formation and early evolution of the Solar System, with theoretical simulations showing that it should change with distance from the Sun and with time in the first few million years.
- One key goal is to compare the value for different kinds of object with that measured for Earth’s oceans, in order to determine how much each type of object may have contributed to Earth’s water.
- Comets in particular are unique tools for probing the early Solar System: they harbor material left over from the protoplanetary disc out of which the planets formed, and therefore should reflect the primordial composition of their places of origin. - But thanks to the dynamics of the early Solar System, this is not a straightforward process. Long-period comets that hail from the distant Oort cloud originally formed in Uranus–Neptune region, far enough from the Sun that water ice could survive. They were later scattered to the Solar System’s far outer reaches as a result of gravitational interactions with the gas giant planets as they settled in their orbits.
- Conversely, Jupiter-family comets like Rosetta’s comet were thought to have formed further out, in the Kuiper Belt beyond Neptune. Occasionally these bodies are disrupted from this location and sent towards the inner Solar System, where their orbits become controlled by the gravitational influence of Jupiter.
- Indeed, Rosetta’s comet now travels around the Sun between the orbits of Earth and Mars at its closest and just beyond Jupiter at its furthest, with a period of about 6.5 years.
Legend to Figure 150: Rosetta’s measurement of the deuterium-to-hydrogen ratio (D/H) measured in the water vapor around Comet 67P/Churyumov–Gerasimenko. The measurements were made using ROSINA’s DFMS double focusing mass spectrometer between 8 August and 5 September 2014.
Deuterium is an isotope of hydrogen with an added neutron. The ratio of deuterium to hydrogen in water is a key diagnostic to determining where in the Solar System an object originated and in what proportion asteroids and/or comets contributed to Earth’s oceans.
Figure 150 displays the different values of D/H in water observed in various bodies in the Solar System. The data points are grouped by color as planets and moons (blue), chondritic meteorites from the Asteroid Belt (grey), comets originating from the Oort cloud (purple) and Jupiter family comets (pink). Rosetta’s Jupiter-family comet is highlighted in yellow. Diamonds represent data obtained in situ; circles represent data obtained by astronomical methods. The lower part of the graph shows the value of D/H measured in molecular hydrogen in the atmosphere of the giant planets of the Solar System (Jupiter, Saturn, Uranus, Neptune) and an estimate of the typical value in molecular hydrogen for the protosolar nebula, from which all objects in our Solar System formed.
The ratio for Earth’s oceans is 1.56 x10–4 (shown as the blue horizontal line in the upper part of the graph). The value for Comet 67P/Churyumov–Gerasimenko is found to be 5.3 x 10–4, more than three times greater than for Earth’s oceans. The discovery fuels the debate on the origin of Earth’s oceans and whether asteroids or comets played the bigger role in delivering water.
Table 17: Some background on previous measurements of the D/H ratio (Ref. 221)
Legend to Figure 151: Deuterium is an isotope of hydrogen with an added neutron. The ratio of deuterium to hydrogen in water is a key diagnostic to determining where in the Solar System an object originated and in what proportion asteroids and/or comets contributed to Earth’s oceans.
The data points are grouped by color as planets and moons (blue), chondritic meteorites from the Asteroid Belt (grey), comets originating from the Oort cloud (purple) and Jupiter family comets (pink). Rosetta’s Jupiter-family comet is highlighted in yellow. Diamonds represent data obtained in situ; circles represent data obtained by astronomical methods. The lower part of the graph shows the value D/H measured in molecular hydrogen in the atmosphere of the giant planets of the Solar System (Jupiter, Saturn, Uranus, Neptune) and an estimate of the typical value in molecular hydrogen for the protosolar nebula, from which all objects in our Solar System formed.
The horizontal blue line shows the value of the ratio in Earth's oceans, which has been determined to be 1.56 x 10–4. Rosetta’s ROSINA instrument measured the water vapor emanating from Comet 67P/Churyumov–Gerasimenko and found it to be 5.3 x 10–4, more than three times greater than for Earth’s oceans.
The discovery fuels the debate on the origin of Earth’s oceans and whether asteroids or comets played the bigger role in delivering water.
Legend to Figure 152: The illustration shows the two main reservoirs of comets in the Solar System: the Kuiper Belt, at a distance of 30–50 astronomical units (AU: the Earth–Sun distance) from the Sun, and the Oort Cloud, which may extend up to 50 000–100 000 AU from the Sun.
Halley’s comet is thought to originate from the Oort Cloud, while 67P/Churyumov–Gerasimenko, the focus of ESA’s Rosetta mission, hails from the Kuiper Belt. It is now in a 6.5-year orbit around the Sun between the orbits of Earth and Mars at its closest and just beyond Jupiter at its furthest.
• Nov. 28, 2014: Data collected by ROMAP (Rosetta Lander Magnetometer and Plasma Monitor) onboard Philae, is being used to help reconstruct the trajectory of the lander to its final landing site on Comet 67P/Churyumov-Gerasimenko. The scientists have now been able to use ROMAP data to reconstruct the chain of events that took place on 12 November as follows: 227)
- Separation was confirmed as a decay in the magnetic field perturbation as the distance between Philae and the orbiter increased; at this point the lander was spinning at a rate of about 1 rotation per 5 minutes.
- The ROMAP boom was deployed successfully and a magnetic field decay was measured corresponding to the increased distance of the ROMAP sensor with respect to its original position on the lander.
- During the seven-hour descent, all measurements were nominal, and ROMAP recorded the first touchdown at 15:34:04 GMT spacecraft time (the signal arrived on Earth just over 28 minutes later, and was confirmed at 16:03 GMT).
- After the first touchdown, the spin rate started increasing. As the lander bounced off the surface, the control electronics of the flywheel were turned off and during the following 40 minutes of flight, the flywheel transferred its angular momentum to Philae. After this time, the lander was spinning at a rate of about 1 rotation per 13 seconds.
- At 16:20 GMT spacecraft time the lander is thought to have collided with a surface feature, a crater rim, for example.
“It was not a touchdown like the first one, because there was no signature of a vertical deceleration due to a slight dipping of the magnetometer boom as measured during the first and also the final touchdown,” according to Hans-Ulrich Auster, the PI of ROMAP at the TU Braunschweig. It is assumed that Philae probably touched a surface with one leg only – perhaps grazing a crater rim – and after that the lander was tumbling. No simple rotation about the lander’s z-axis could be seen.
- Following this event, the main rotation period had decreased slightly to 1 rotation per 24 seconds.
- At 17:25:26 GMT, Philae touched the surface again, initially with just one foot but then all three, giving the characteristic touchdown signal.
- At 17:31:17 GMT, after travelling probably a few more meters, Philae found its final parking position on three feet.
Despite this bumpy start to its life on the comet, all of Philae’s instruments were operated in the following two days. — The search for Philae’s final landing spot is still on, and the ROMAP data are being used with other instrument data from both Philae and Rosetta to try to reconstruct the lander’s full trajectory and to identify its current location. Also, a comprehensive scientific analysis of the data from all instruments is underway.
• Nov. 19, 2014: With the Philae lander’s mission complete, Rosetta will now continue its own extraordinary exploration, orbiting Comet 67P/Churymov–Gerasimenko during the coming year as the enigmatic body arcs ever closer to our Sun. The Rosetta spacecraft is in excellent condition, with all of its systems and instruments performing as expected. 228)
- Rosetta will become the first spacecraft to witness at close quarters the development of a comet’s coma and the subsequent tail streaming for millions of kilometers into space. Rosetta will then have to stay further from the comet to avoid the coma affecting its orbit. - In addition, as the comet nears the Sun, illumination on its surface is expected to increase. This may provide sufficient sunlight for the DLR-operated Philae lander, now in hibernation, to reactivate, although this is far from certain.
- Early next year, Rosetta will be switched into a mode that allows it to listen periodically for beacon signals from the surface.
• Nov. 17, 2014: The mosaic series in Figure 153 show the breathtaking journey of Rosetta’s Philae lander as it approached and then rebounded from its first touchdown on Comet 67P/Churyumov–Gerasimenko on November 12, 2014. The images were taken with Rosetta’s OSIRIS narrow-angle camera when the spacecraft was 17.5 km from the comet center, or roughly 15.5 km from the surface. They have a resolution of 28 cm/pixel and the enlarged insets are 17 m x 17 m. 229) 230) 231)
Figure 153: Mosaic of Rosetta’s OSIRIS narrow-angle camera on Nov. 12 spotting Philae drifting across the comet (image credit: ESA, Rosetta,MPS for OSIRIS Team MPS, UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA)
Legend to Figure 153: The mosaic comprises a series of images captured by Rosetta’s OSIRIS camera over a 30 minute period spanning the first touchdown. The time of each of image is marked on the corresponding insets and is in GMT. A comparison of the touchdown area shortly before and after first contact with the surface is also provided.
From left to right, the images show Philae descending towards and across the comet before touchdown. The image taken after touchdown, at 15:43 GMT, confirms that the lander was moving east, as first suggested by the data returned by the CONSERT experiment, and at a speed of about 0.5 m/s.
The final location of Philae is still not known, but after touching down and bouncing again at 17:25 GMT, it reached there at 17:32 GMT. The imaging team is confident that combining the CONSERT ranging data with OSIRIS and NAVCAM images from the orbiter and images from near the surface and on it from Philae’s ROLIS and CIVA cameras will soon reveal the lander’s whereabouts (Ref. 229).
Before going into hibernation at 00:36 GMT ( 01:36 CET) on 15 November 2014, the Philae lander was able to conduct some work using power supplied by its primary battery. With its 10 instruments, the mini laboratory sniffed the atmosphere, drilled, hammered and studied Comet 67P/ Churyumov-Gerasimenko while over 500 million km from Earth (Ref. 230).
• Nov. 15, 2014: Rosetta’s lander Philae has completed its primary science mission after nearly 57 hours on Comet 67P/Churyumov–Gerasimenko. 232)
- After being out of communication visibility with the lander since 09:58 GMT / 10:58 CET on Nov. 14 (Friday), Rosetta regained contact with Philae at 22:19 GMT /23:19 CET last night (Nov. 14). The signal was initially intermittent, but quickly stabilized and remained very good until 00:36 GMT / 01:36 CET this morning (Nov. 15). — In this period, the lander returned all of its housekeeping data, as well as science data from the targeted instruments, including ROLIS, COSAC, Ptolemy, SD2 and CONSERT. This completed the measurements planned for the final block of experiments on the surface.
- In addition, the lander’s body was lifted by about 4 cm and rotated about 35° in an attempt to receive more solar energy. But as the last science data fed back to Earth, Philae’s power rapidly depleted. — “It has been a huge success, the whole team is delighted,” said Stephan Ulamec, lander manager at the DLR German Aerospace Agency, who monitored Philae’s progress from ESOC in Darmstadt, Germany, this week. - “We still hope that at a later stage of the mission, perhaps when we are nearer to the Sun, that we might have enough solar illumination to wake up the lander and re-establish communication, ” added Stephan.
- From now on, no contact will be possible unless sufficient sunlight falls on the solar panels to generate enough power to wake it up. The possibility that this may happen later in the mission was boosted when mission controllers sent commands to rotate the lander’s main body with its fixed solar panels. This should have exposed more panel area to sunlight.
- Meanwhile, the Rosetta orbiter has been moving back into a 30 km orbit around the comet. t will return to a 20 km orbit on Dec. 6, 2014 and continue its mission to study the body in great detail as the comet becomes more active, en route to its closest encounter with the Sun on August 13, 2015. Over the coming months, Rosetta will start to fly in more distant ‘unbound’ orbits, while performing a series of daring flybys past the comet, some within just 8 km of its center.
Data collected by the orbiter will allow scientists to watch the short- and long-term changes that take place on the comet, helping to answer some of the biggest and most important questions regarding the history of our Solar System. How did it form and evolve? How do comets work? What role did comets play in the evolution of the planets, of water on the Earth, and perhaps even of life on our home world.
“The data collected by Philae and Rosetta is set to make this mission a game-changer in cometary science,” says Matt Taylor, ESA’s Rosetta project scientist. Fred Jansen, ESA’s Rosetta mission manager, says, “At the end of this amazing rollercoaster week, we look back on a successful first-ever soft-landing on a comet. This was a truly historic moment for ESA and its partners. We now look forward to many more months of exciting Rosetta science and possibly a return of Philae from hibernation at some point in time.”
Figure 154: Labelled trajectory of Rosetta’s orbit, focusing on the maneuvers after 12 November 2014 (image credit: ESA, Ref. 232)
• Nov.14, 2014 (update information): Although the Philae touchdown was confirmed at ESOC to have occurred at 16:03 GMT/17:03 CET on 12 November, scientists, flight dynamics specialists and engineers from all mission participants have been studying the first data returned from the lander. These revealed the astonishing conclusion that the lander did not just touch down on Comet 67P/Churyumov–Gerasimenko once, but three times. 233)
- The harpoons did not fire and Philae appeared to be rotating after the first touchdown, which indicated that it had lifted from the surface again. Stephan Ulamec, Philae manager at the DLR German Aerospace Center, reported that it touched the surface at 15:34, 17:25 and 17:32 GMT (comet time – it takes over 28 minutes for the signal to reach Earth, via Rosetta). The information was provided by several of the scientific instruments, including the ROMAP magnetic field analyzer, the MUPUS thermal mapper, and the sensors in the landing gear that were pushed in on the first impact.
- The first touchdown was inside the predicted landing ellipse, confirmed using the lander’s downwards-looking ROLIS descent camera in combination with the orbiter’s OSIRIS images to match features.
- But then the lander lifted from the surface again – for 1 hour 50 minutes. During that time, it travelled about 1 km upward at a speed of 38 cm/s. It then made a smaller second hop, travelling at about 3 cm/s, and landing in its final resting place seven minutes later.
- The touchdown signal generated on first touchdown induced the instruments to ‘think’ that Philae had landed, triggering the next sequence of experiments. Now those data are being used to interpret the bounces.
- The lander remains unanchored to the surface at an as yet undetermined orientation. The science instruments are running and are delivering images and data, helping the team to learn more about the final landing site.
- The descent camera revealed that the surface is covered by dust and debris ranging in size from mm to m. Meanwhile, Philae’s CIVA camera returned a panoramic image that on first impressions suggests the lander is close to a rocky wall, and perhaps has one of its three feet in open space.
- After discussions as to whether to activate those science instruments that may cause the position of Philae to shift, MUPUS and APXS have both been deployed.
- The primary battery enabling the core science goals of the lander may run out some time in the next 24 hours. As for the secondary battery, charged by solar panels on Philae, with only 1.5 hours of sunlight available to the lander each day, there is an impact on the energy budget to conduct science for a longer period of time. The original landing site offered nearly seven hours of illumination per 12.4 hour comet day.
• Nov. 13, 2014: Rosetta’s lander Philae is safely on the surface of Comet 67P/Churyumov-Gerasimenko (Figure 156). One of the lander’s three feet can be seen in the foreground. The image is a two-image mosaic of CIVA (Comet Nucleus Infrared and Visible Analyzer), a group of six identical micro-cameras. 234) 235)
- Philae landed nearly vertically on its side with one leg up in outer space. Philae settled into its final landing spot after a harrowing first bounce that sent it flying as high as a kilometer above the comet’s surface. After hovering for two hours, it landed a second time only to bounce back up again a short distance – this time 3 cm. Seven minutes later it made its third and final landing. Incredibly, the little craft still functions after trampolining for hours!
- Despite its awkward stance, Philae continues to do a surprising amount of good science. Scientists are still hoping to come up with a solution to better orientate the lander. Their time is probably limited. The craft landed in the shadow of a cliff, blocking sunlight to the solar panels used to charge its battery. Philae receives only 1.5 hours instead of the planned 6-7 hours of sunlight each day.
Figure 155: Stephan Ulamec, Philae Lander manager, describes how Philae first landed less than 100 m from the planned Agilkia site (red square). Without functioning harpoons and thrusters to fix it to the ground there, it rebounded and shot a kilometer above the comet. Right now, it’s somewhere in the blue diamond (image credit: ESA)
• Nov. 12, 2014: The following statement is from John Grunsfeld, astronaut and associate administrator for NASA’s Science Mission Directorate in Washington, about the successful comet landing by the European Space Agency’s Rosetta spacecraft: 236)
- “We congratulate ESA on their successful landing on a comet today. This achievement represents a breakthrough moment in the exploration of our solar system and a milestone for international cooperation. We are proud to be a part of this historic day and look forward to receiving valuable data from the three NASA instruments on board Rosetta that will map the comet’s nucleus and examine it for signs of water.
- “The data collected by Rosetta will provide the scientific community, and the world, with a treasure-trove of data. Small bodies in our solar system like comets and asteroids help us understand how the solar system formed and provide opportunities to advance exploration. We look forward to building on Rosetta's success exploring our solar system through our studies of near earth asteroids and NASA's upcoming asteroid sample return mission OSIRIS-REx. It’s a great day for space exploration."
Figure 156: First CIVA camera image of the Philae lander on the surface of Comet 67P/Churyumov-Gerasimenko (image credit: ESA, Rosetta, Philae, CIVA)
• Nov. 12, 2014: Philae has landed! ESA’s Rosetta mission has soft-landed its Philae probe on a comet, the first time in history that such an extraordinary feat has been achieved. After a tense wait during the seven-hour descent to the surface of Comet 67P/Churyumov–Gerasimenko, the signal confirming the successful touchdown arrived on Earth at 16:03 GMT (17:03 CET). 237)
- The confirmation was relayed via the Rosetta orbiter to Earth and picked up simultaneously by ESA’s ground station in Malargüe, Argentina and NASA’s station in Madrid, Spain. The signal was immediately confirmed at ESA/ESOC, in Darmstadt, and DLR’s Lander Control Center in Cologne, both in Germany. The first data from the lander’s instruments were transmitted to the Philae Science, Operations and Navigation Center at France’s CNES space agency in Toulouse.
- Touchdown was planned to take place at a speed of around 1 m/s, with the three-legged landing gear absorbing the impact to prevent rebound, and an ice screw in each foot driving into the surface.
- Over the next 2.5 days, the lander will conduct its primary science mission, assuming that its main battery remains in good health. An extended science phase using the rechargeable secondary battery may be possible, assuming the Sun illumination conditions allow and dust settling on the solar panels does not prevent it. This extended phase could last until March 2015, after which conditions inside the lander are expected to be too hot for it to continue operating.
- Science highlights from the primary phase will include a full panoramic view of the landing site, including a section in 3D, high-resolution images of the surface immediately underneath the lander, on-the-spot analysis of the composition of the comet’s surface materials, and a drill that will take samples from a depth of 23 cm and feed them to an onboard laboratory for analysis.
- The lander will also measure the electrical and mechanical characteristics of the surface. In addition, low-frequency radio signals will be beamed between Philae and the orbiter through the nucleus to probe the internal structure. The detailed surface measurements that Philae makes at its landing site will complement and calibrate the extensive remote observations made by the orbiter covering the whole comet.
- While Philae begins its close-up study of the comet, Rosetta must maneuver from its post-separation path back into an orbit around the comet, eventually returning to a 20 km orbit on December 6, 2014. The plans of the ground-breaking Rosetta mission are to follow the comet around the Sun for 13 months, watching as its activity changes and its surface evolves.
- Next year, as the comet grows more active, Rosetta will need to step further back and fly unbound ‘orbits’, but dipping in briefly with daring flybys, some of which will bring it within just 8 km of the comet center.
- The comet will reach its closest distance to the Sun on 13 August 2015 at about 185 million km, roughly between the orbits of Earth and Mars. Rosetta will follow it throughout the remainder of 2015, as they head away from the Sun and activity begins to subside.
• Nov. 12, 2014 [at 10:02 CET (Central European Time)]: The Philae lander has separated from the Rosetta orbiter, and is now on its way to becoming the first spacecraft to touch down on a comet. Separation was confirmed at ESA/ESOC at 09:03 GMT. It takes the radio signals from the transmitter on Rosetta 28 minutes and 20 seconds to reach Earth, so separation actually occurred in space at 08:35 GMT. 238)
- The first signal from Philae is expected in around two hours, when the lander establishes a communication link with Rosetta. Philae cannot send its data to Earth directly – it must do it via Rosetta. Once the link has been established, the lander will relay via Rosetta a status report of its health, along with the first science data. This will include images taken of the orbiter shortly after separation.
- The descent to the surface of Comet 67P/Churyumov–Gerasimenko will take around seven hours, during which the lander will take measurements of the environment around the comet. It will also take images of the final moments of descent.
- Confirmation of a successful touchdown is expected in a one-hour window centered on 17:02 GMT. The first image from the surface is expected some two hours later.
Figure 157: Infographic to summarize the measurements carried out by Rosetta’s lander, Philae, during its seven-hour descent to Comet 67P/Churyumov–Gerasimenko and immediately after touchdown (image credit: ESA/ATG medialab)
Figure 158: Rosetta’s lander Philae took this parting shot of its mothership shortly after separation. The image was taken with the lander’s CIVA-P imaging system and captures one of Rosetta's 14 m long solar arrays. It was stored onboard the lander until the radio link was established with Rosetta around two hours after separation, and then relayed to Earth (image credit: ESA, Rosetta, Philae, CIVA). 239)
Figure 159: Rosetta’s OSIRIS narrow-angle camera captured this parting shot of the Philae lander after separation (image credit: ESA, Rosetta,MPS for OSIRIS Team MPS, UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA) 240)
Figure 160: First photo released of Comet 67P/C-G taken by the ROLIS camera of Philae during its descent on Nov. 12 at 14:38:41 UTC from a distance of ~3 km from the surface. The landing site is imaged with a resolution of about 3 m per pixel (image credit: DLR) 241)
Legend to Figure 160: The ROLIS camera is a down-looking imager that acquires images during the descent and doubles as a multispectral close-up camera after the landing. The aim of the ROLIS experiment is to study the texture and microstructure of the comet's surface. In the upper right corner a segment of the Philae landing gear is visible.
• November 11, 2014: ESA’s comet-chasing Rosetta mission spent much of the second half of October orbiting Comet 67P/Churyumov–Gerasimenko at less than 10 km from its surface. This selection of previously unpublished ‘beauty shots’, taken by Rosetta’s navigation camera, presents the varied and dramatic terrain of this mysterious world from this close orbit phase of the mission. 242)
- Some light contrast enhancements have been made to emphasize certain features and to bring out features in the shadowed areas. In reality, the comet is extremely dark — blacker than coal. The images, taken in black-and-white, are grey-scaled according to the relative brightness of the features observed, which depends on local illumination conditions, surface characteristics and composition of the given area. Some slight vignetting can also be seen in the corners of some images.
Figure 161: This NAVCAM image showcases one of the many pits seen on the surface of 67P/Churyumov–Gerasimenko (image credit: ESA,Rosetta, NAVCAM)
Legend to Figure 161: Pits like these are thought to be where gas vents into space from the porous subsurface, carrying with it dusty grains of comet material. Scientists are keen to learn the role of this pit – and others – in the development of the comet’s activity, as it gets ever closer to the Sun.
This single-frame NAVCAM image measures 1024 x 1024 pixels. It was captured from a distance of 9.9 km from the center of the comet (about 7.7 km from the surface) at 02:22 GMT on 15 October 2014. At this distance, the image resolution is 84.6 cm/pixel and the size of the image is 866 x 866 m.
Figure 162: Image of the dark side of Comet 67P/Churyumov-Gerasimenko (image credit: ESA, Rosetta,MPS for OSIRIS Team MPS, UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA)
Legend to Figure 162: This image of comet 67P/Churyumov-Gerasimenko was obtained on October 30, 2014 by the OSIRIS scientific imaging system on the Rosetta spacecraft. The right half is obscured by darkness. The image was taken from a distance of approximately 30 km.
- The landing site, previously known as ‘Site J’, is named for Agilkia Island, an island on the Nile River in the south of Egypt. A complex of Ancient Egyptian buildings, including the famous Temple of Isis, was moved to Agilkia from the island of Philae when the latter was flooded during the building of the Aswan dams last century.
- The name was selected by a jury comprising members of the Philae Lander Steering Committee as part of a public competition run 16–22 October by ESA and the German, French and Italian space agencies.
- Agilkia was one of the most popular entries – it was proposed by over 150 participants. The committee selected Alexandre Brouste from France as the overall winner. As a prize, Mr. Brouste will be invited to ESA’s Space Operations Control Centre in Darmstadt, Germany, to follow the landing live.
- Although perhaps not quite as complicated as navigating Rosetta and Philae towards the comet, the task of choosing a name was by no means simple. More than 8000 entries from 135 countries were received in one week, showing great creativity and cultural diversity.
- The entries covered a tremendous range of themes, from abstract concepts to the names of places on Earth. As with the winning entry, many suggestions echoed the Egyptian origins of Rosetta and Philae, named in recognition of milestones in decoding hieroglyphics, the sacred writing system of ancient Egypt.
Figure 163: The Philae landing site Agilkia is located on the 'head' of Comet 67P/Churyumov-Gerasimenko (image credit: ESA, DLR)
• October 20-24, 2014: In the “Our week through the lens” series, ESA released an image of Comet 67P/Churyumov-Gerasimenko (Figure 164), showing jets of cometary activity along almost the entire body of the comet. 247) 248)
Figure 164: The OSIRIS wide-angle camera shows comet activity acquired on September 10, 2014 (image credit: ESA, Rosetta,MPS for OSIRIS Team MPS, UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA)
• October 15, 2014: ESA has given the green light for its Rosetta mission to deliver its lander, Philae, to the primary site on 67P/Churyumov–Gerasimenko on 12 November, in the first-ever attempt at a soft touchdown on a comet. 249)
- Philae’s landing site, currently known as Site J and located on the smaller of the comet’s two ‘lobes’, was confirmed on 14 October following a comprehensive readiness review. — Since the arrival, the mission has been conducting an unprecedented survey and scientific analysis of the comet, a remnant of the early phases of the Solar System’s 4.6 billion-year history.
- At the same time, Rosetta has been moving closer to the comet: starting at 100 km on 6 August, it is now just 10 km from the center of the 4 km-wide body. This allowed a more detailed look at the primary and backup landing sites in order to complete a hazard assessment, including a detailed boulder census.
- The decision that the mission is ‘Go’ for Site J also confirms the timeline of events leading up to the landing. Rosetta will release Philae at 08:35 GMT/09:35 CET on 12 November at a distance of approximately 22.5 km from the center of the comet. Landing will be about seven hours later at around 15:30 GMT/16:30 CET (Central European Time).
- With a one-way signal travel time between Rosetta and Earth on 12 November of 28 minutes 20 seconds, that means that confirmation of separation will arrive on Earth ground stations at 09:03 GMT/10:03 CET and of touchdown at around 16:00 GMT/17:00 CET.
Figure 165: Philae’s primary landing site – mosaic (image credit: ESA, Rosetta,MPS for OSIRIS Team MPS, UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA)
• October 10, 2014: The OSIRIS camera on board Europe’s Rosetta spacecraft has caught a spectacular glimpse of one of the many boulders that cover the surface of comet 67P/Churyumov-Gerasimenko. With a maximum extension of 45 m, it is one of the larger structures of this kind on the comet and stands out among a group of boulders located on the lower side of 67P’s larger lobe. Since this cluster of boulders reminded the scientists of the pyramids of Giza, the boulder has been named Cheops after the largest pyramid within the Giza Necropolis of Egypt. The boulder-like structures that Rosetta has revealed on the surface of 67P in the past months are one of the comet’s most striking and mysterious features. 250)
The large boulder now dubbed Cheops was seen for the first time in images obtained in early August upon Rosetta’s arrival at the comet (Figure 177). In the past weeks as Rosetta has navigated closer and closer to the comet’s surface, OSIRIS imaged the unique structure again – but this time with a much higher resolution of 50 cm/pixel. The image of Figure 166 was acquired on Sept. 19, 2014 from a distance of 28.5 km. 251)
Figure 166: Close-up of the boulder Cheops as it casts a long shadow on the surface of comet 67P/Churyumov-Gerasimenko, (image credit: ESA, Rosetta,MPS for OSIRIS Team MPS, UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA)
• On October 8, 2014, ESA reports of grooves found on asteroid Lutetia when Rosetta flew past Lutetia at a distance of 3168 km in July 2010. The spacecraft took images of the 100 km-wide asteroid for about two hours during the flyby, revealing numerous impact craters and hundreds of grooves all over the surface. 252)
Impact craters are commonly seen on all Solar System worlds with solid surfaces, recording an intense history of collisions between bodies. However, grooves are much less prevalent. To date, they have been discovered by visiting spacecraft only on the martian moon Phobos and the asteroids Eros and Vesta.
Figure 167: Tracing Lutetia's grooves,”(image credit: ESA)
• Oct. 3, 2014: Comet 67P/Churyumov-Gerasimenko's dimensions, as measured from images taken by Rosetta's OSIRIS imaging system. The images shown in the graphic were taken by Rosetta's navigation camera on August 19, 2014. - The larger lobe of the comet measures 4.1 x 3.2 x 1.3 km, while the smaller lobe is 2.5 x 2.5 x 2.0 km. 253)
- One of the key things is the so-called “shape model”, meaning a 3D model of the comet based on images from the OSIRIS and NAVCAM cameras. Because roughly 30% of the ‘dark side’ of 67P/C-G has not been resolved and analyzed fully yet, the shape model is very incomplete over those regions. As a result, some of the derived parameters for the comet are only best estimates at present. These include the volume and the global density, the latter depending on the mass and the volume. 254)
Figure 168: Measuring Comet 67P/C-G (image credit: ESA, Rosetta/OSIRIS; Dimensions: ESA, Rosetta, MPS for OSIRIS Team MPS, UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA)
• September 26, 2014: The Rosetta mission will deploy its lander, Philae, to the surface of Comet 67P/Churyumov-Gerasimenko on November 12, 2014. Philae's landing site, currently known as Site J, is located on the smaller of the comet's two 'lobes', with a backup site on the larger lobe. The sites were selected just six weeks after Rosetta arrived at the comet on 6 August, following its 10-year journey through the Solar System. 255)
- The primary landing site was chosen from five candidates during the Landing Site Selection Group meeting held on 13–14 September 2014.
Figure 169: Rosetta's NAVCAM camera took this image of Comet 67P/Churyumov-Gerasimenko on 21 September, from a distance of 27.8 km from the comet center. The image covers an area of about 2 km x 1.9 km and focuses on the smaller of the two comet lobes. The primary landing site J is 'above' the distinctive depression in this view (image credit: ESA, Rosetta). 256)
Figure 170: Site J is located on the head of Comet 67P/Churyumov–Gerasimenko. An inset showing a close up of the landing site is also shown (image credit: ESA, Rosetta, MPS for OSIRIS Team MPS, UPD, LAM, IAA SSO, INTA, UPM, DASP, IDA)
Legend to Figure 170: The inset image was taken by Rosetta's OSIRIS narrow-angle camera on 20 August 2014 from a distance of about 67 km. The image scale is 1.2 m/pixel. The background image was taken on 16 August from a distance of about 100 km. The comet nucleus is about 4 km across.
• Sept. 5, 2014: After examining the images of the comet obtained on August 6, members of the Rosetta team at ESA couldn’t help but notice that Comet 67P/C-G appeared to be a very oddly shaped object. Its peculiar shape led them to nickname the comet the “rubber duck”. As the team continues to study Comet 67P/C-G, the scientists are looking to get a better understanding of its surface properties. 257)
- Orbit: Rosetta is in an orbit about the comet at an avearge distance of ~30 km. The team is planning to occasionally lower the spacecraft’s orbit to about 10 km above the comet’s surface or possibly even lower when the Rosetta’s attached Philae lander is deployed in November.
- An ideal landing site for Philae is that would be about 1 km2 in size and able to provide enough sunlight to charge the probe’s battery. - Since the comet’s gravity is so low, the probe will most likely bounce when it first touches down, so ESA engineers have equipped it with two harpoons and some ice screws to keep the probe steady and attached to 67P/C-G’s surface.
• August 25, 2014: Using detailed information collected by ESA’s Rosetta spacecraft during its first two weeks at Comet 67P/Churyumov-Gerasimenko, five locations have been identified as candidate sites to set down the Philae lander in November – the first time a landing on a comet has ever been attempted. 258)
The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images of Figure 171 taken on 16 August from a distance of about 100 km. The comet nucleus is about 4 km across.
The sites were assigned a letter from an original pre-selection of 10 possible sites identified A through J. The lettering scheme does not signify any ranking. Three sites (B, I and J) are located on the smaller of the two lobes of the comet and two sites (A and C) are located on the larger lobe.
Figure 171: Philae candidate landing sites (image credit: ESA, Rosetta, MPS for OSIRIS Team MPS, UPD, LAM, IAA SSO, INTA, UPM, DASP, IDA)
The landing of Philae is expected to take place in mid-November when the comet is about 450 million km from the Sun, before activity on the comet reaches levels that might jeopardise the safe and accurate deployment of Philae to the comet’s surface, and before surface material is modified by this activity.
The comet is on a 6.5 year orbit around the Sun and today is 522 million km from it. At their closest approach on 13 August 2015, just under a year from now, the comet and Rosetta will be 185 million km from the Sun, meaning an eightfold increase in the light received from the Sun.
While Rosetta and its scientific instruments will watch how the comet evolves as heating by the Sun increases, observing how its coma develops and how the surface changes over time, the lander Philae and its instruments will be tasked with making complementary in situ measurements at the comet’s surface. The lander and orbiter will also work together using the CONSERT experiment to send and detect radio waves through the comet’s interior, in order to characterise its internal structure.
• Comet characterization (Ref. 263): This phase was mainly driven by the technically challenging and time critical need for the operations team to develop engineering models of the comet such that the proper orbit phase and the landing site selection process could start.
For the team to design and plan the next phase it was necessary to have a pretty accurate model of the gravity field and of the comet attitude with an associated reference frame. In total absence of further information about the comet, the first step of the process was to catalog the so-called landmarks i.e. evident features of the comet’s surface that could easily be recognized in the images and used as navigation references. The position of these landmarks in subsequent images and the traditional radiometric data (ranging and Doppler) were then fed into the orbit determination system which essentially consisted of an estimator of:
- Spacecraft position and velocity
- Comet position and velocity
- Comet spin axis
- Comet attitude evolution (thus rotation period)
- Comet gravity potential (thus mass) and position of the center of mass
- Comet shape.
Due to the extremely large inaccuracy in the a priori knowledge of the comet’s gravity potential it was not possible to inject the spacecraft onto a proper captured orbit. Therefore all these measurements were collected from a so-called “pyramid orbit” consisting of a sequence of three portions of hyperbolic arcs flown in front of the comet, on the illuminated side (Figure 172), at a distance varying between 115 and 90 km. In this way the spacecraft was not captured by the gravity but would still be in a position to have its orbit affected by it and have the possibility to observe the comet from different angles.
Figure 172: Pyramid orbits (image credit: ESA/ESOC)
This triangular trajectory was flown for 10 days and, after a transfer of 7 days, another triangle was flown at distances ranging from 70 to 50 km (Figure 173).
The timeline of events reported in Table 18 shows the time pressure the operations team was encountering during this phase (major events in bold italics). This was mainly due to the need of starting the landing site selection process as soon as possible to meet the delivery deadline of mid November 2014. During this phase the conceived mission planning concept revealed to be extremely robust and was key to the success. At the same time the full complement of scientific instruments was performing uninterrupted scientific measurements.
The estimation phase of cometary parameters and the development of the relevant models was conducted according to plan with the first full operational set released on 14 August at the end of the 2nd segment of the first triangle. At this stage also the shape model of the comet was available with an accuracy level beyond the expectations. The only estimation process that took longer to converge was the one determining the position of the center of mass of the comet. The comet was found – unexpectedly - not to be nutating at all and this had the consequence that the position of the center of mass could only be estimated from the spacecraft orbital reconstruction without any aid from the optical images.
This phase also marked the transition from far approach optical navigation, where images were used to compute the position of the comet with respect to fixed stars, to proximity navigation, where the spacecraft position with respect to the comet is determined by the position of the landmarks in the images. Due to the active environment around the comet, where rather unpredictable aerodynamic forces act on the spacecraft, the proximity optical navigation method will constitute the basis for navigation throughout the mission. This imposes specific constraints for operations planning (e.g. regular image taking sessions capable of coping with pointing uncertainties) and execution (e.g. availability of recent optical navigation data for orbit determination and commands generation sessions) that have to be considered by the operations team.
The models developed at this stage were accurate enough to kick-off the next two steps of the mission:
- the design of the orbital phase
- the landing site selection process.
Figure 173: Comet distance during pyramid orbits (image credit: ESA/ESOC)
Table 18: Events during comet characterization
Orbit operations and preparation for landing:
The whole orbiting plan for the phase immediately following the comet characterization (i.e. the 2 pyramid orbits) was fully dependant on the actual comet parameters, mainly spin axis and mass. With these parameters resolved, it was possible for the operations team to plan and release the operational orbits. These include an initial orbital phase at ca. 29 km radius with orbital plane tilted 60º away from the Sun direction then followed by a phase where the orbit radius is reduced to ca. 19 km and the orbital plane is moved to the terminator plane (Figure 174).
Figure 174: Global mapping and close observation orbits (image credit: ESA/ESOC)
A further reduction of the orbit radius will be conducted only if allowed by the dynamical stability of the comet environment. This strategy was necessary to combine the wish of the scientists to have good observation conditions with the need to minimize the spacecraft surface exposed to the – mostly radial - gas flow coming from the comet. The terminator plane, being perpendicular to the Sun direction, ensures that only the edge of the solar arrays is exposed to the gas flow, thus minimizing the aerodynamic forces acting on the spacecraft.
This orbital phase is considered as most valuable by the vast majority of the scientists in charge of Rosetta’s on-board instruments because it might be the only opportunity to fly orbits so close to the surface, at least in this initial comet operations phase. In any case, with the decrease of the heliocentric distance the comet is expected to increase its activity and will force the operations team to fly at larger distances from the comet nucleus.
• On 6 August 2014, the Rosetta mission achieved a significant milestone by becoming the first mission to rendezvous with a comet. During the coming months, Rosetta will orbit the comet, deploy the Philae lander (in November, 2014), and accompany the comet through perihelion (August 2015) until the nominal end of the mission. 259)
- After a decade-long journey chasing its target, ESA’s Rosetta has today become the first spacecraft to rendezvous with a comet, opening a new chapter in Solar System exploration. 260)
Comet 67P/Churyumov–Gerasimenko and Rosetta now lie 405 million km from Earth, about half way between the orbits of Jupiter and Mars, rushing towards the inner Solar System at nearly 55 000 km/hr.
The comet is in an elliptical 6.5 year orbit that takes it from beyond Jupiter at its furthest point, to between the orbits of Mars and Earth at its closest to the Sun. Rosetta will accompany it for over a year as they swing around the Sun and back out towards Jupiter again.
Figure 175: Rosetta's OSIRIS narrow-angle camera image of Comet 67P/Churyumov–Gerasimenko on August 3, 2014 from a distance of 285 km, image resolution = 5.3 m (image credit: ESA, Rosetta, MPS for OSIRIS Team MPS, UPD, LAM, IAA SSO, INTA, UPM, DASP, IDA)
- The comet began to reveal its personality while Rosetta was on its approach. Images taken by the OSIRIS camera between late April and early June showed that its activity was variable. The comet’s ‘coma’ – an extended envelope of gas and dust – became rapidly brighter and then died down again over the course of those six weeks.
In the same period, first measurements from the MIRO (Microwave Instrument) on the Rosetta Orbiter suggested that the comet was emitting water vapor into space at about 300 ml/s (milliliter).
Meanwhile, VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) measured the comet’s average temperature to be about –70ºC, indicating that the surface is predominantly dark and dusty rather than clean and icy.
Then, stunning images taken from a distance of about 12 000 km began to reveal that the nucleus comprises two distinct segments joined by a ‘neck’, giving it a duck-like appearance. Subsequent images showed more and more detail (Figures 175 and 176) — the most recent, highest-resolution image was downloaded from the spacecraft on August 8 (Figure 177).
Figure 176: Comet on 3 August 2014 the by the OSIRIS narraow-angle camera from a distance of 285 km, image resolution = 5.3 m (image credit: ESA, Rosetta, MPS for OSIRIS Team MPS, UPD, LAM, IAA SSO, INTA, UPM, DASP, IDA)
Legend to Figure 177: Stunning close up detail focusing on a smooth region on the ‘base’ of the ‘body’ section of comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle camera and downloaded today, 6 August. The image clearly shows a range of features, including boulders, craters and steep cliffs. - The image was taken from a distance of 130 km and the image resolution is 2.4 m.
• August 2, 2014: An image of the comet's activity was acquired (Figure 178) with the OSIRIS camera from a distance of 550 km. The exposure time of the image was 330 seconds and the comet nucleus is saturated to bring out the detail of the comet activity.
Figure 178: The image was taken by Rosetta’s OSIRIS wide-angle camera from a distance of 550 km (image credit: ESA, Rosetta, MPS for OSIRIS Team MPS, UPD, LAM, IAA SSO, INTA, UPM, DASP, IDA)
• During May - August 2014, Rosetta was executing a series of 10 OCMs (Orbit Correction Maneuvers) to line itself up for arrival at comet 67P on August 6 – approximately one burn every two weeks in May and June, and one per week in July (see also Table 19). 262)
- The first, on 7 May, was quite small, achieving a ΔV of just 20 m/s (with respect to the comet).
- The second was carried out on 21 May, referred to as Big Burn, it lasted for 7 hrs and 16minutes, used 218 kg of propellant and delivered a total ΔV of 289.59 m/s. During the OCM, teams at ESOC monitored parameters such as temperature and pressure of the four thrusters.
- Big Burn2 was on June 4 resulting in a ΔV of 269.5 m/s. At this event, Rosetta was 425, 250 km from the comet, approaching at a relative speed of 463 m/s. The one-way radio signal time to Earth was 25 min:56 seconds.
• Following the January 2014 wake-up of the Rosetta spacecraft after the hibernation period, Rosetta conducted the delicate approach phase during which it slowly discovered its unexpected irregular shape. In order to complete the rendezvous as planned Rosetta had to reduce the miss- distance to a few tens of km and the relative velocity down to ca. 1 m/s. This could have been possible by imparting to the spacecraft a n acceleration of ca. 775 m/s at the right time on June 3, resulting in the two objects flying on the same heliocentric orbit. - However, the uncertainties in the knowledge of the orbit of the comet (ca. 10000 km on the position) were such that it was not possible to conduct this operation without further information. For this reason an optical navigation campaign was designed and conducted such that by means of images taken by the spacecraft the flight controllers at the Mission Control Center at ESOC were in a position to reconstruct the relative trajectories of the two bodies with incremental accuracy. Figure 179 shows how Rosetta was flying on the illuminated side of the comet, a mandatory configuration for the conduct of the optical navigation campaign. 263)
The rendezvous maneuver was split into a sequence of 10 single maneuvers spread over a period of ca. 3 months, during which the parameters of the relative trajectory were resolved to the accuracy required for a successful orbit insertion. Table 19 reports the details of the maneuvers as conducted. The last four columns report respectively:
- the date of the comet flyby in case the manoeuvre would not have been executed before the relevant flyby date
- the distance of the flyby as determined with the orbit reconstruction process
- the 3σ uncertainty associated to this distance
- the time margin the operations team had to complete the manoeuvre before the spacecraft would fly-past the comet and find itself to have to come back on the night side of the comet with limited optical navigation capabilities.
Table 19: Sequence of rendezvous maneuvers
The optical navigation campaign was conducted with images initially taken by the OSIRIS/NAC and later by the spacecraft Navigation Camera (NAVCAM). The very first set of images acquired with the NAC ( Figure 180) at the end of March 2014, when the comet was at ca. 4.8 million km from the spacecraft, allowed the operations team to determine that the comet was ca. 2000 km away from its expected position i.e. well within the expected uncertainty.
Figure 179: Rosetta and comet orbits (image credit: ESA/ESOC)
Figure 180: OSIRIS/NAC view of comet 67P/CG taken on 21 March, 2014 (image credit: ESA, MPS for OSIRIS-Team MPS,UPD, LAM, IAA, SSO, INTA, UPM, DASP, IDA)
• After the successful wakeup, Rosetta and Philae underwent a post hibernation commissioning. The orbiter instruments (like e.g. the OSIRIS cameras, VIRTIS, MIRO, Alice and ROSINA) characterize the target comet and its environment to allow landing site selection and the definition of a separation, descent and landing (SDL) strategy for the Lander (Ref. 63).
- The first switch-on of the Philae lander took place on March 28, 2014, when an updated software for the CDMS (Central Data Management System) was uploaded. This activity was followed by three commissioning blocks, where all lander subsystems and instruments were activated, EEPROMs have been refreshed and in some cases new software was uploaded. No major degradation has been observed, the lander was found to be in a state very similar as during the checkouts before entering hibernation.
- The lander was switched on for several further occasions, before the actual SDL (Separation, Descent and Landing) sequence will be initiated in November. The so-colled PDCS (Pre-Delivery Calibration and Science) phase includes background measurements and “sniffing” of the mass spectrometers (PTOLEMY and COSAC), calibration of the CIVA cameras as well as imaging of the comet nucleus, parallel operations of ROMAP with RPC (magnetic field, ion environment) and activation of CONSERT. The solar generator performance has been verified and the secondary batteries are cycled for capacity degradation measurement.
• January 20, 2014 : ESA's Rosetta orbiter woke up from a 31 month hibernation period at 18:18 GMT to begin an ambitious year of operations to become the first craft to rendezvous with a comet, follow it as it makes its close approach to the Sun and deploy the Philae lander onto its surface. 264)
- Operating on solar energy alone, Rosetta was placed into a deep space slumber in June 2011 as it cruised out to a distance of nearly 800 million km from the warmth of the Sun, beyond the orbit of Jupiter. Now, as Rosetta’s orbit has brought it back to within ‘only’ 673 million km from the Sun, there is enough solar energy to power the spacecraft fully again. - Thus today, still about 9 million km from the comet, Rosetta’s pre-programmed internal ‘alarm clock’ woke up the spacecraft. After warming up its key navigation instruments, coming out of a stabilising spin, and aiming its main radio antenna at Earth, Rosetta sent a signal to let mission operators know it had survived the most distant part of its journey.
- The signal was received by both of NASA’s Goldstone and Canberra ground stations during the first window of opportunity the spacecraft had to communicate with Earth. It was immediately confirmed at ESOC in Darmstadt and the successful wake-up announced.
• June 8, 2011: The final command placing ESA's Rosetta comet-chaser into deep-space hibernation was sent earlier today. With virtually all systems shut down, the probe will now coast for 31 months until waking up in 2014 for arrival at its comet destination. 265)
The event marks the end of the hugely successful first phase of Rosetta's ten-year cruise and the start of a long, dark hibernation during which all instruments and almost all control systems will be silent. The deep sleep is made necessary by the craft's enormous distance from the Sun and the weakness of the sunlight falling on its solar panels, which cannot produce enough electricity to power the probe fully.
Only the computer and several heaters will remain active. These will be automatically controlled to ensure that the entire satellite doesn't freeze as its orbit takes it from 660 million km from the Sun out to 790 million km and back between now and 2014.
• July 10, 2010: Asteroid Lutetia has been revealed as a battered world of many craters. ESA’s Rosetta mission has returned the first close-up images of the asteroid showing it is most probably a primitive survivor from the violent birth of the Solar System. The flyby was a spectacular success with Rosetta performing faultlessly. Closest approach took place at 18:10 CEST (Central European Standard Time), at a distance of 3162 km. 266)
- Lutetia is one of the largest objects orbiting within the main asteroid belt between Mars and Jupiter. Rosetta's encounter revealed an intriguing object which has survived since the birth of the planets, some 4.5 billion years ago. 267)
Discovered in 1852, Lutetia was among the first objects to be classified as an M-type (metallic) asteroid, but radar observations revealed an unusually low albedo, or reflectivity, that was inconsistent with a metallic surface. Meanwhile, spectra obtained at visible and infrared wavelengths found similarities with meteorites known as enstatite chondrites and with carbonaceous chondrite meteorites, typically associated with C-type asteroids.
Figure 181: OSIRIS camera image of Lutetia at closest approach (image credit: ESA)
• Sept. 5, 2008: The Rosetta control room at ESA/ESOC received the first radio signal after closest approach to asteroid (2867) Steins at 22:14 CEST, confirming a smooth fly-by. The closest approach was at a distance of 800 km. Rosetta’s relative speed with respect to asteroid Steins was 8.6 km/s, or about 31 000 km/h. 268)
- The first images from Rosetta’s OSIRIS imaging system and VIRTIS infrared spectrometer were derived from raw data this morning and have delivered spectacular results. 269)
Figure 182: Anaglyph image of Steins in 3D acquired at about the closest approach (image credit: ESA, MPS for OSIRIS Team MPS,UPD, LAM, IAA, RSSD,INTA,UPM, DASP, IDA)
- The observations by OSIRIS and VIRTIS on Rosetta brought new information that could not have been gained from the ground. The dimensions of Steins were found to be 6.67 x 5.81 x 4.47 km3. Rosetta scientists believe that Steins was part of a larger differentiated object that had broken up. It was later struck by other objects, creating impact craters. However, the interior is thought to be a rubble pile and the asteroid will eventually break up. 270)
Figure 183: Artist's view of the Rosetta spacecraft on its way to Comet 67P/Churyumov–Gerasimenko (image credit: DLR) 271)
• On Feb. 25, 2007, the Rosetta spacecraft encountered planet Mars for a gravity assit. The image of Figure 184 was taken just four minutes before the spacecraft reached closest approach, about 1,000 km from the planet’s surface. An area close to the Syrtis region is visible on the planet’s disk (Ref. 58).
Figure 184: CIVA image of Mars acquired on Feb. 25, 2007 showing portions of the Rosetta spacecraft with Mars in the background (image credit: J. P. Bibring, CIVA, Philae, ESA)
• After launch on March 2, 2004, the Rosetta spacecraft was first inserted into a parking orbit, before being sent on its way towards the outer Solar System. 272)
Unfortunately, no existing rocket, not even the powerful European-built Ariane-5, has the capability to send such a large spacecraft directly to Comet 67P/Churyumov-Gerasimenko. Instead, Rosetta will bounce around the inner Solar System like a ‘cosmic billiard ball’, circling the Sun almost four times during its ten-year trek to Comet 67P/Churyumov-Gerasimenko.
Along this roundabout route, Rosetta will enter the asteroid belt twice and gain velocity from gravitational ‘kicks’ provided by close flybys of Mars (2007) and Earth (2005, 2007 and 2009).
Figure 185: Image of Comet 67P/Churyumov–Gerasimenko acquired with the Hubble Space Telescope on March 12, 2003 (image credit: NASA, ESA, P. Lamy)
Results from NASA's Hubble Space Telescope played a major role in preparing ESA's ambitious Rosetta mission for its new target, comet 67P/Churyumov-Gerasimenko (67P/C-G). For the first time in history, Rosetta will land a probe on a comet and study its origin. Hubble precisely measured the size, shape, and rotational period of comet 67P/C-G.
Hubble's observations revealed that comet 67P/C-G is approximately a three-by-two mile, football-shaped object on which it is possible to land. Mission scientists were concerned that the solid nucleus could be nearly 3.6 miles (6 km) across. The higher gravity on a comet that size might make a soft landing more difficult.
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110) ”Unexpected surprise: a final image from Rosetta,” ESA, 28 Sept. 2017, URL: http://m.esa.int/Our_Activities/Space_Science/Rosetta/Unexpected_surprise_a_final_image_from_Rosetta
111) ”Rosetta finds comet connection to Earth's atmosphere,” ESA, 8 June 2017, URL: http://sci.esa.int/rosetta/59177-Rosetta-finds-comet-connection-to-earth-s-atmosphere/
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113) ”Xenon across the Solar System,” ESA Science & Technology, Rosetta, 8 June 2017, URL: http://sci.esa.int/rosetta/59182-xenon-across-the-solar-system/
114) ”Collapsing cliff reveals comet’s interior,” ESA, March 21, 2017, URL: http://m.esa.int/Our_Activities/Space_Science/Rosetta/Collapsing_cliff_reveals_comet_s_interior
115) ”Before and after: unique changes spotted on Rosetta’s comet,” ESA, March 21, 2017, URL: http://m.esa.int/Our_Activities/Space_Science/Rosetta/Before_and_after_unique_changes_spotted_on_Rosetta_s_comet
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120) ”Comet landing sites in context,” ESA, Sept. 23, 2016, URL: http://m.esa.int/spaceinimages/Images/2016/09/Comet_landing_sites_in_context
121) ”Icy surprises at Rosetta's comet,” ESA, Nov. 17, 2016, URL: http://sci.esa.int/rosetta/58575-icy-surprises-at-rosetta-s-comet/
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124) ”Mission complete: Rosetta’s journey ends in daring descent to comet,” ESA, Sept. 30, 2016, URL: http://sci.esa.int/rosetta/58382-mission-complete-rosettas-journey-ends-in-daring-descent-to-comet/
125) ”Rosetta's Descent -image highlights captured during Rosetta’s descent to the comet’s surface,” ESA, Sept. 30, 2016, URL: http://m.esa.int/Our_Activities/Space_Science/Rosetta/Highlights/Rosetta_s_descent
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127) ”Rosetta measures production of water at comet over two years,” ESA, Sept. 27, 2016, URL: http://sci.esa.int/rosetta/58349-rosetta-measures-production-of-water-at-comet-over-two-years/
128) Kenneth C. Hansen, K. Altwegg, J.-J. Berthelier, A. Bieler, N. Biver, D. Bockelée-Morvan, U. Calmonte, F. Capaccioni, M. R. Combi, J. De Keyser, B. Fiethe, N. Fougere, S. A. Fuselier, S. Gasc, T. I. Gombosi, Z. Huang, L. Le Roy, S. Lee, H. Nilsson, M. Rubin, Y. Shou, C. Snodgrass, V. Tenishev, G. Toth, C.-Y. Tzou, C. Simon Wedlund, the ROSINA team, ”Evolution of water production of 67P/Churyumov-Gerasimenko: An empirical model and a multi-instrument study,” Monthly Notices of the Royal Astronomical Society, MNRAS (2016) doi: 10.1093/mnras/stw2413, First published online September 26, 2016, URL: http://mnras.oxfordjournals.org/content/early/2016/09/23/mnras.stw2413.full.pdf#page=1&view=FitH
129) Nicolas Fougere, K. Altwegg, J.-J. Berthelier, A. Bieler, D. Bockelée-Morvan, U. Calmonte, F. Capaccioni, M. R. Combi, J. De Keyser, V. Debout, S. Erard, B. Fiethe, G. Filacchione, U. Fink, S. A. Fuselier, T. I. Gombosi, K. C. Hansen, M. Hässig, Z. Huang, L. Le Roy, C. Leyrat, A. Migliorini, G. Piccioni, G. Rinaldi, M. Rubin, Y. Shou, V. Tenishev, G. Toth, C.-Y. Tzou, the VIRTIS and the ROSINA teams, ”Direct Simulation Monte-Carlo Modeling of the Major Species in the Coma of Comet 67P/Churyumov-Gerasimenko,” MNRAS (2016) doi: 10.1093/mnras/stw2388, First published online September 20, 2016
130) ”Summer fireworks on Rosetta’s comet,” ESA, Sept. 23, 2016, URL: http://m.esa.int/Our_Activities/Space_Science/Rosetta/Summer_fireworks_on_Rosetta_s_comet
131) J.-B. Vincent, M. F. A'Hearn, Z.-Y. Lin, M. R. El-Maarry, M. Pajola, H. Sierks, C. Barbieri, P. L. Lamy, R. Rodrigo, D. Koschny, H. Rickman, H. U. Keller, J. Agarwa, M. A. Barucci, J.-L. Bertaux, I. Bertini, S. Besse, D. Bodewits, G. Cremonese, V. Da Deppo, B. Davidsson, S. Debei, M. De Cecco, J. Deller, S. Fornasier, M. Fulle, A. Gicque, O. Groussin, P. J. Gutierrez, P. Gutierrez-Marquez, C. Güttler, S. Höfner; M. Hofmann, S. F. Hviid, W.-H. Ip, L. Jorda, J. Knollenberg, G. Kovacs, J.-R. Kramm, E. Kührt, M. Küuppers, L. M. Lara, M. Lazzarin, J. J. Lopez Moreno, F. Marzar, M. Massironi, S. Mottola, G. Naletto, N. Oklay, F. Preusker, F. Scholten, X. Shi, N. Thomas, I. Toth, C. Tubiana, ”Summer fireworks on comet 67P,”, MNRAS (Monthly Notices of the Royal Astronomical Society), Advance Access published on September 22, 2016, doi: 10.1093/mnras/stw2409, URL: http://mnras.oxfordjournals.org/content/early/2016/09/21/mnras.stw2409.full.pdf#page=1&view=FitH
132) ”Rosetta’s descent towards region of active pits,” ESA, Sept. 9, 2016, URL: http://m.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_descent_towards_region_of_active_pits
133) ”Rosetta's descent towards region of active pits,” ESA, Sept. 9, 2016, URL: http://sci.esa.int/rosetta/58248-rosetta-s-descent-towards-region-of-active-pits/
134) ”Rosetta catches dusty organics,” ESA, Sept. 7, 2016, URL: http://sci.esa.int/rosetta/58233-rosetta-catches-dusty-organics/
135) Nicolas Fray, Anaïs Bardyn, Hervé Cottin, Kathrin Altwegg, Donia Baklouti, Christelle Briois, Luigi Colangeli, Cécile Engrand, Henning Fischer, Albrecht Glasmachers, Eberhard Grün, Gerhard Haerendel, Hartmut Henkel, Herwig Höfner, Klaus Hornung, Elmar K. Jessberger, Andreas Koch, Harald Krüger, Yves Langevin, Harry Lehto, Kirsi Lehto, Léna Le Roy, Sihane Merouane, Paola Modica, François-Régis Orthous-Daunay , et al., Nature Letter” published online 07 September, 2016, doi:10.1038/nature19320, ”High-molecular-weight organic matter in the particles of comet 67P/Churyumov-Gerasimenko,”
136) ”Philae found!”, ESA, Sept. 5, 2016, URL: http://m.esa.int/Our_Activities/Space_Science/Rosetta/Philae_found
137) ”Comet lander Philae found,” DLR, Sept. 5, 2016, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-19204/year-all/#/gallery/24223
138) ”Rosetta captures comet outburst,” ESA, Aug. 25, 2016, URL: http://sci.esa.int/rosetta/58176-rosetta-captures-comet-outburst/
139) Eberhard Grün, ”The 19 Feb. 2016 Outburst of Comet 67P/CG: A Rosetta Multi-Instrument Study,” Monthly Notices of the Royal Astronomical Society. doi: 10.1093/mnras/stw2088
140) ”How comets are born,” ESA, July 28, 2016, URL: http://sci.esa.int/rosetta/58119-how-comets-are-born/
141) B. J. R. Davidsson, H. Sierks, C. Güttler, F. Marzari, M. Pajola, H. Rickman, M. F. A’Hearn, A.-T. Auger, M. R. El-Maarry, S. Fornasier, P. J. Gutiérrez, H. U. Keller, M. Massironi, C. Snodgrass, J.-B. Vincent, C. Barbieri, P. L. Lamy, R. Rodrigo, D. Koschny, M. A. Barucci, J.-L. Bertaux, I. Bertini, G. Cremonese, V. Da Deppo, S. Debei, M. De Cecco, C. Feller, M. Fulle, O. Groussin, S. F. Hviid, S. Höfner, W.-H. Ip, L. Jorda, J. Knollenberg, G. Kovacs, J.-R. Kramm, E. Kührt, M. Küppers, F. La Forgia, L. M. Lara, M. Lazzarin, J. J. Lopez Moreno, R. Moissl-Fraund, S. Mottola, G. Naletto, N. Oklay, N. Thomas, C. Tubiana, ”The primordial nucleus of comet 67P/Churyumov-Gerasimenko,” Astronomy & Astrophysics, Volume 592, August 2016, doi: http://dx.doi.org/10.1051/0004-6361/201526968 , published online: July 26, 2016, URL: http://www.aanda.org/articles/aa/pdf/2016/08/aa26968-15.pdf
142) ”Say goodbye to Philae,” DLR, July 26, 2016, URL: http://www.dlr.de/blogs/en/home/philae/Say-goodbye-to-Philae.aspx
143) ”CometWatch 9 July,” ESA, July 15, 2016, URL: http://blogs.esa.int/rosetta/2016/07/15/cometwatch-9-july/
144) ”Rosetta finale set for 30 September,” ESA, June 30, 2016, URL: http://sci.esa.int/rosetta/58020-rosetta-finale-set-for-30-september/
145) ”Rosetta's comet contains ingredients for life,” ESA, May 27, 2016, URL: http://sci.esa.int/rosetta/57858-rosettas-comet-contains-ingredients-for-life/
146) Kathrin Altwegg, Hans Balsiger, Akiva Bar-Nun, Jean-Jacques Berthelier, Andre Bieler, Peter Bochsler, Christelle Briois, Ursina Calmonte, Michael R. Combi, Hervé Cottin, Johan De Keyser, Frederik Dhooghe, Bjorn Fiethe, Stephen A. Fuselier, Sébastien Gasc, Tamas I. Gombosi, Kenneth C. Hansen, Myrtha Haessig, Annette Jäckel, Ernest Kopp, Axel Korth, Lena Le Roy, Urs Mall, Bernard Marty, Olivier Mousis, Tobias Owen, Henri Rème, Martin Rubin, Thierry Sémon, Chia-Yu Tzou, James Hunter Waite, Peter Wurz, ”Prebiotic chemicals—amino acid and phosphorus—in the coma of comet 67P/Churyumov-Gerasimenko,” Science Advances, 27 May 2016, Vol. 2, No 5, e1600285, doi: 10.1126/sciadv.1600285, URL:http://advances.sciencemag.org/content/advances/2/5/e1600285.full.pdf
147) ”Around Anuket,” ESA, Space Science image of the week, April 18, 2016, URL: http://www.esa.int/spaceinimages/Images/2016/04/Around_Anuket
148) ”The color-changing comet,” ESA, April 7, 2016, URL: http://www.esa.int/spaceinimages/Images/2016/04/The_colour-changing_comet
149) Gianrico Filacchione, Fabrizio Capaccioni, Mauro Ciarniello, Andrea Raponi, Federico Tosi, Maria Cristina De Sanctis, Stéphane Erard, Dominique Bockelée Morvan, Cedric Leyrat, Gabriele Arnold, Bernard Schmitt, Eric Quirico, Giuseppe Piccioni, Alessandra Migliorini, Maria Teresa Capria, Ernesto Palomba, Priscilla Cerroni, Andrea Longobardo, Antonella Barucci, Sonia Fornasier, Robert W. Carlson, Ralf Jaumann, Katrin Stephan, Lyuba V. Moroz, David Kappel, Batiste Rousseau, Sergio Fonti, Francesca Mancarella, Daniela Despan, Mathilde Faure, ”The global surface composition of 67P/CG nucleus by Rosetta/VIRTIS. (I) Prelanding mission phase,” Ikarus, Available online 16 March 2016, doi:10.1016/j.icarus.2016.02.055, URL: http://tinyurl.com/hsvnjv8
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151) ”Rosetta finds magnetic field-free bubble at comet,” ESA, March 11, 2016, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_finds_magnetic_field-free_bubble_at_comet
152) ”Rosetta’s lander faces eternal hibernation,” ESA, Feb. 12, 2016, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_lander_faces_eternal_hibernation
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154) ”Inside Rosetta's Comet,” ESA, Feb. 4, 2016, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Inside_Rosetta_s_comet
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176) Matteo Massironi, Emanuele Simioni, Francesco Marzari, Gabriele Cremonese, Lorenza Giacomini, Maurizio Pajola, Laurent Jorda, Giampiero Naletto, Stephen Lowry, Mohamed Ramy El-Maarry, Frank Preusker, Frank Scholten, Holger Sierks, Cesare Barbieri, Philippe Lamy, Rafael Rodrigo, Detlef Koschny, Hans Rickman, Horst Uwe Keller, Michael F. A’Hearn, Jessica Agarwal, Anne-Thérèse Auger, M. Antonella Barucci, Jean-Loup Bertaux, Ivano Bertini, et al., ”Two independent and primitive envelopes of the bilobate nucleus of comet 67P,” Nature, Letter, published online Sept. 28, 2015, doi:10.1038/nature15511, URL: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature15511.html
177) ”ESA's Rosetta spacecraft has provided evidence for a daily water-ice cycle on and near the surface of comets,” ESA, Sept. 23, 2016, URL: http://sci.esa.int/rosetta/56513-rosetta-reveals-comet-s-water-ice-cycle/
178) M. C. De Sanctis, F. Capaccioni, M. Ciarniello, G. Filacchione, M. Formisano, S. Mottola, A. Raponi, F. Tosi, D. Bockelée-Morvan, S. Erard, C. Leyrat, B. Schmitt, E. Ammannito, G. Arnold, M. A. Barucci, M. Combi, M. T. Capria, P. Cerroni, W.-H. Ip, E. Kuehrt, T. B. McCord, E. Palomba, P. Beck, E. Quirico & The VIRTIS Team, ”The diurnal cycle of water ice on comet 67P/Churyumov–Gerasimenko,” Nature, Vol. 525, pp: 500–503, 24 September 2015, doi:10.1038/nature14869
179) ”The water-ice cycle of Rosetta's comet,” ESA, Sept. 23, 2015, URL: http://sci.esa.int/rosetta/56514-the-water-ice-cycle-of-rosettas-comet/
180) “Rosetta Mission: Ptolemy sniffs next piece of the comet puzzle,” OU (Open University), Sept. 15, 2015, URL: http://www3.open.ac.uk/media/fullstory.aspx?id=29376
181) Andrew Morse, Olivier Mousis, Simon Sheridan, Geraint Morgan, Dan Andrews, Simeon Barber, Ian Wright, “Low CO/CO2 ratios of comet 67P measured at the Abydos landing site by the Ptolemy mass spectrometer,” Astronomy & Astrophysics, 2015, DOI: 10.1051/0004-6361/201526624
182) “Rosetta's big day in the Sun,” ESA, August 12, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_big_day_in_the_Sun
183) “Comet's firework display ahead of perihelion,” ESA, Aug. 11, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Comet_s_firework_display_ahead_of_perihelion
184) “Comet on 6 August 2014 and 6 August 2015,” ESA Space Science Image of the week, August 10, 2015, URL: http://www.esa.int/spaceinimages/Images/2015/08/Comet_on_6_August_2014_and_6_August_2015
185) “Celebrating a year at the comet,” ESA, August 6, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Celebrating_a_year_at_the_comet
186) “Science on the surface of a comet,” ESA, July 30, 2015, URL: http://sci.esa.int/rosetta/56250-science-on-the-surface-of-a-comet/
187) J.-P. Bibring, M. G. G. T. Taylor, C. Alexander, U. Auster, J. Biele, A. Ercoli Finzi, F. Goesmann, G. Klingelhoefer, W. Kofman, S. Mottola, K. J. Seidensticker, T. Spohn, I. Wright , “Philae’s First Days On The Comet,” Science, Vol. 349, No 6247, p. 493, July 31, 2015, URL: http://www.sciencemag.org/content/349/6247/493.full
188) ”Philae's adapted first science sequence,” ESA, July 30,2015, URL: http://sci.esa.int/rosetta/56273-philae-adapted-first-science-sequence/
189) “Headache for Philae,” DLR News, July 20, 2015, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-14272/year-all/#/gallery/20036
190) “Rosetta: Preparing for Perihelion,” ESA, July 13, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_preparing_for_perihelion
191) “New communication with Philae – commands executed successfully,” DLR, July 10, 2015, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-14156/year-all/#/gallery/17198
192) “Comet sinkholes generate jets,” ESA, July 1, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Comet_sinkholes_generate_jets
193) Jean-Baptiste Vincent, Dennis Bodewits, Sébastien Besse, Holger Sierks, Cesare Barbieri, Philippe Lamy, Rafael Rodrigo, Detlef Koschny, Hans Rickman, Horst Uwe Keller, Jessica Agarwal, Michael F. A'Hearn, Anne-Thérèse Auger, M. Antonella Barucci, Jean-Loup Bertaux, Ivano Bertini, Claire Capanna, Gabriele Cremonese, Vania Da Deppo, Björn Davidsson, Stefano Debei, Mariolino De Cecco, Mohamed Ramy El-Maarry, Francesca Ferri, Sonia Fornasier, et al.,“Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse,” Nature Letter, Vol. 523, pp: 63–66, published online 01 July 2015, doi:10.1038/nature14564
194) “Active pits on comet,” ESA, URL: http://www.esa.int/spaceinimages/Images/2015/07/Active_pits_on_comet
195) “Contact with Philae still irregular and unstable,” DLR, June 26, 2015, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-14019/year-all/#/gallery/311
196) “Exposed water ice detected on Comet's surface,” ESA, June 24, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Exposed_water_ice_detected_on_comet_s_surface
197) A. Pommerol, N. Thomas, M. R. El-Maarry, M. Pajola, O. Groussin, A.-T. Auger, N. Oklay, S. Fornasier, C. Feller, B. Davidsson, A. Gracia-Berná, B. Jost, R. Marschall, O. Poch, M. A. Barucci, J. -L. Bertaux, F. La Forgia, H. U. Keller; 10, E. Kührt, S. C. Lowry, S. Mottola, G. Naletto, H. Sierks, C. Barbieri, P. L. Lamy, R. Rodrigo, D. Koschny, H. Rickman, J. Agarwal, M. F. A’Hearn, I. Bertini, S. Boudreault, G. Cremonese, V. Da Deppo, M. De Cecco, S. Debei, C. Güttler, M. Fulle, P. J. Gutierrez, S. F. Hviid, W. -H. Ip, L. Jorda, J. Knollenberg, G. Kovacs, J. -R. Kramm, E. Küppers, L. Lara, M. Lazzarin, J. L. Lopez Moreno, F. Marzari, H. Michalik, F. Preusker, F. Scholten, C. Tubiana, J. -B. Vincent, “OSIRIS observations of meter-sized exposures of H2O ice at the surface of 67P/Churyumov-Gerasimenko and interpretation using laboratory experiments,” Astronomy & Astrophysics, Accepted 15 May 2015, URL: http://www.aanda.org/articles/aa/pdf/forth/aa25977-15.pdf
198) “Rosetta mission extended,” ESA, June 23, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_mission_extended
199) “Lander Control Center in contact with Philae once again,” DLR, June 19, 2015, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-13980/year-all/#/gallery/17198
200) “Philae wake-up kicks off intense planning,” ESA, June 15, 2016, URL: http://sci.esa.int/rosetta/56029-philae-wake-up-kicks-off-intense-planning/
201) Manuela Braun, Sephan Ulamec, “Lander Philae is awake – 'Hello' from space,” DLR, June 14, 2015, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-13900/year-all/#/gallery/2563
202) “Rosetta's Lander Philae wakes up from hibernation,” ESA, June 14, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_lander_Philae_wakes_up_from_hibernation
203) “Ultraviolet study reveals surprises in comet coma,” ESA, June 2, 2015, URL: http://sci.esa.int/rosetta/55963-ultraviolet-study-reveals-surprises-in-comet-coma/
204) DC Agle, Dwayne Brown, Joe Fohn, Markus Bauer, “NASA Instrument on Rosetta Makes Comet Atmosphere Discovery,” NASA, June 2, 2015, URL: http://www.nasa.gov/jpl/nasa-instrument-on-rosetta-makes-comet-atmosphere-discovery
205) Paul D. Feldman, Michael F. A'Hearn, Jean-Loup Bertaux, Lori M. Feaga, Joel Wm. Parker, Eric Schindhelm, Andrew J. Steffl , S. Alan Stern, Harold A. Weaver, Holger Sierks, Jean-Baptiste Vincent, “Measurements of the Near-Nucleus Coma of Comet 67P/Churyumov-Gerasimenko with the Alice Far-Ultraviolet Spectrograph on Rosetta,” accepted for publication in Astronomy and Astrophysics, arXiv:1506.01203 [astro-ph.EP], DOI: 10.1051/0004-6361/201525925
206) “Rosetta and Philae find comet not magnetized,” ESA, April 14, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_and_Philae_find_comet_not_magnetised
207) “Rosetta and Philae find comet not magnetized,” ESA, April 14, 2015, URL: http://sci.esa.int/rosetta/55788-rosetta-and-philae-find-comet-not-magnetised/
209) Hans-Ulrich Auster, Istvan Apathy, Gerhard Berghofer, Karl-Heinz Fornacon, Anatoli Remizov, Chris Carr, Carsten Güttler, Gerhard Haerendel, Philip Heinisch, David Hercik, Martin Hilchenbach, Ekkehard Kührt, Werner Magnes, Uwe Motschmann, Ingo Richter, Christopher T. Russell, Anita Przyklenk, Konrad Schwingenschuh, Holger Sierks, Karl-Heinz Glassmeier, “The non-magnetic nucleus of Comet 67P/Churyumov-Gerasimenko," Science Express, April 14, 2015, DOI: 10.1126/science.aaa5102
210) “Comet activity 31 January – 25 March 2015,” ESA, April 13, 2015, URL: http://www.esa.int/spaceinimages/Images/2015/04/Comet_activity_31_January_25_March_2015
211) “Waiting patiently for Philae,” DLR, March 20, 2015, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-13123/year-all/#/gallery/2564
212) “Rosetta makes first detection of molecular nitrogen at a comet,” ESA, March 19, 2015, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_makes_first_detection_of_molecular_nitrogen_at_a_comet
213) “All-round activity – CometWatch 25-26-27 February, “ ESA, March 4, 2015, URL: http://blogs.esa.int/rosetta/2015/03/04/all-round-activity-cometwatch-25-26-27-february/
214) “Comet flyby: OSIRIS catches glimpse of Rosetta’s shadow,” ESA, March 3, 2015, URL: http://blogs.esa.int/rosetta/2015/03/03/comet-flyby-osiris-catches-glimpse-of-rosettas-shadow/
215) “Rosetta's closest encounter,” ESA, Feb. 17, 2015, URL: http://www.esa.int/spaceinvideos/Videos/2015/02/Rosetta_s_closest_encounter
216) “Comet on 14 February from 8.7 km,” ESA, Feb. 16, 2015, URL: http://www.esa.int/spaceinimages/Images/2015/Comet_on_14_February_from_8.7_km
217) “Rosetta watches comet shed its dusty coat,” ESA, January 26, 2015, URL: http://sci.esa.int/rosetta/55341-rosetta-watches-comet-shed-its-dusty-coat/
218) Rita Schulz, Martin Hilchenbach, Yves Langevin, Jochen Kissel, Johan Silen, Christelle Briois, Cecile Engrand, Klaus Hornung, Donia Baklouti, Anaïs Bardyn, Hervé Cottin, Henning Fischer, Nicolas Fray, Marie Godard, Harry Lehto, Léna Le Roy, Sihane Merouane, François-Régis Orthous-Daunay, John Paquette, Jouni Rynö, Sandra Siljeström, Oliver Stenzel, Laurent Thirkell, Kurt Varmuza, Boris Zaprudin, “Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years,” Nature, Published online 26 January 2015 , doi:10.1038/nature14159
219) “Getting to know Rosetta's comet,” ESA, January 22, 2015, URL: http://sci.esa.int/rosetta/55295-getting-to-know-rosetta-s-comet/
220) “Rosetta fuels debate on origin of Earth’s oceans,” ESA, Dec. 10, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_fuels_debate_on_origin_of_Earth_s_oceans
221) K. Altwegg, H. Balsiger, A. Bar-Nun, J. J. Berthelier, A. Bieler, P. Bochsler, C. Briois, U. Calmonte, M. Combi, J. De Keyser, P. Eberhardt, B. Fiethe, S. Fuselier, S. Gasc, T. I. Gombosi, K. C. Hansen, M. Hässig, A. Jäckel, E. Kopp, A. Korth, L. LeRoy, U. Mall, B. Marty, O. Mousis, E. Neefs, T. Owen, H. Rème, M. Rubin, T. Sémon, C.-Y. Tzou, H. Waite, P. Wurz, “67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio,” Science, December 10, 2014, Science DOI: 10.1126/science.1261952
222) “Rosetta fuels debate on origin of Earth’s oceans,” UKSA, Dec. 11, 2014, URL: https://www.gov.uk/government/news/rosetta-fuels-debate-on-origin-of-earths-oceans
223) Emily Baldwin, Carl Walker, “Living with a Comet, Rosetta in ictures, August-November 2014,” ESA Bulletin, No 160, November 2014, pp:2-13, URL: http://esamultimedia.esa.int/multimedia/publications/ESA-Bulletin-160/
224) “First measurements of comet’s water ratio,” ESA, Dec. 10, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/12/First_measurements_of_comet_s_water_ratio
225) “Deuterium-to-hydrogen in the Solar System,” ESA, Dec. 10, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/12/Deuterium-to-hydrogen_in_the_Solar_System
226) “Kuiper Belt and Oort Cloud in context,” ESA, Dec. 10, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/12/Kuiper_Belt_and_Oort_Cloud_in_context
227) “Did Philae graze a crater rim during its first bounce?,” ESA, Nov. 28, 2014, URL: http://blogs.esa.int/rosetta/2014/11/28/did-philae-graze-a-crater-rim-during-its-first-bounce/
228) “Rosetta continuous into its full science phase,” ESA, Nov. 19, 2014, URL: http://www.esa.int/Our_Activities/Operations/Rosetta_continues_into_its_full_science_phase
229) “OSIRIS spots Philae drifting across the comet,” ESA, Nov. 17, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/11/OSIRIS_spots_Philae_drifting_across_the_comet
230) “Churyumov-Gerasimenko – hard ice and organic molecules,” DLR News, Nov. 17, 2014, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-12176/year-all/#/gallery/17219
231) “Philae finds hard ice and organic molecules,” UKSA, Nov. 18, 2014, URL: https://www.gov.uk/government/news/philae-finds-hard-ice-and-organic-molecules
232) “Pioneering Philae completes main mission before hibernation,” ESA, Nov. 15, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Pioneering_Philae_completes_main_mission_before_hibernation
233) “Three touchdowns for Rosetta's lander,” ESA, Nov. 14, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Three_touchdowns_for_Rosetta_s_lander
234) “Welcome to a comet,” ESA, Nov. 13, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/11/Welcome_to_a_comet
235) “Comet media briefing replay,” ESA, Nov. 13, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_media_briefing_replay
236) Dwayne Brown, ”NASA Statement on Successful Rosetta Comet Landing,” NASA Release 14-315, Nov. 12, 2014, URL: https://www.nasa.gov/press/2014/november/nasa-statement-on-successful-rosetta-comet-landing/
237) “Touchdown! Rosetta's Philae Probe lands on Comet,” ESA, Nov. 12, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Touchdown!_Rosetta_s_Philae_probe_lands_on_comet
238) Rosetta and Philae separation confirmed,” ESA, Nov. 12, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_and_Philae_separation_confirmed
239) “Farewell Rosetta,” ESA, image released on Nov. 12, 2014 at 14:50 CET, URL: http://www.esa.int/spaceinimages/Images/2014/11/Farewell_Rosetta
240) “Farewell Philae - narrow-angle view,” ESA, image released on Nov. 12, 2014 at 15:59 CET, URL: http://www.esa.int/spaceinimages/Images/2014/11/Farewell_Philae_-_narrow-angle_view
241) “ROLIS-camera takes closest picture of Churyumov-Gerasimenko,” DLR, Nov. 12, 2014, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-12091/#/gallery/17139
242) “Top 10 at 10 km,” ESA, Nov. 11, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Highlights/Top_10_at_10_km
243) “Farewell 'J', Hello Agilkia,” ESA, Nov. 4, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Farewell_J_hello_Agilkia
244) “Philae landing site J is now named 'Agilkia',” DLR, Nov. 4, 2014, URL: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-11960/year-all/#/gallery/16768
245) “Once upon a time... preparing for comet landing,” ESA, Nov. 3, 2014, URL: http://www.esa.int/spaceinvideos/Videos/2014/11/Once_upon_a_time_preparing_for_comet_landing
246) DC Agle, Guy Webster, Dwayne Brown, Markus Bauer, “Rosetta Races Toward Comet Touchdown,” NASA/JPL, Nov. 6, 2014, Release 2014-383, URL: http://www.jpl.nasa.gov/news/news.php?feature=4364
247) “Comet activity - 10 September 2014,” ESA, released on Oct. 23, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/10/Comet_activity_10_September_2014
248) Tony Phillips, “How to land on a Comet,” NASA Science News, Nov. 3, 2014, URL: http://science.nasa.gov/science-news/science-at-nasa/2014/03nov_rosettalanding/
249) “ESA confirms the primary landing site for Rosetta,” ESA, Oct. 15, 2014: http://www.esa.int/Our_Activities/Space_Science/Rosetta/ESA_confirms_the_primary_landing_site_for_Rosetta
250) “Close-up of boulder Cheops,” UKSA, Oct. 10, 2014, URL: https://www.gov.uk/government/news/close-up-of-boulder-cheops
251) “Bolder Cheops,” ESA, Our Week in images, Oct. 6-10, 2014, URL: http://www.esa.int/Highlights/Week_In_Images_06_10_October_2014
252) “LutetiaÄs dark side hosts hidden crater,” ESA, Oct. 8, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Lutetia_s_dark_side_hosts_hidden_crater
253) “Measuring Comet 67P/C-G,” ESA, Oct. 3, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/10/Measuring_Comet_67P_C-G
255) “Rosetta to deploy Lander on 12 November,” ESA, Sept. 26, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_to_deploy_lander_on_12_November
257) “ESA’s Rosetta Probe Gets Close to Duck-Shaped Comet 67P/C-K,” ESA, Sept. 5, 2014, URL: http://blogs.voanews.com/science-world/2014/09/05/esas-rosetta-probe-gets-close-to-duck-shaped-comet-67pc-k/
258) “Rosetta: Landing site search narrows,” ESA, August 25, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_Landing_site_search_narrows
260) “Rosetta arrives at comet destination,” ESA, August 6, 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_arrives_at_comet_destination
261) “Comet details,” ESA, Aug. 6, 2014, URL: http://www.esa.int/spaceinimages/Images/2014/08/Comet_details
262) “The Big Burns – Part 2,” ESA, June 3, 2014, URL: http://blogs.esa.int/rosetta/2014/06/03/the-big-burns-part-2/
263) Andrea Accomazzo, Paolo Ferri , Sylvain Lodiot, Jose-Luis Pellon-Bailon, Armelle Hubault, Roberto Porta, Jakub Urbanek, Ritchie Kay , Matthias Eiblmaier, Tiago Francisco, “Rosetta operations at the comet,” Proceedings of the 65th International Astronautical Congress (IAC 2014), Toronto, Canada, Sept. 29-Oct. 3, 2014, paper: IAC-14-A3,4.1
264) “ESA's sleeping beauty wakes up from deep space hibernation,” ESA, Jan. 20. 2014, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/ESA_s_sleeping_beauty_wakes_up_from_deep_space_hibernation
265) “Rosetta comet probe enters hibernation in deep space,” ESA, June 8, 2011, URL: http://www.esa.int/Our_Activities/Operations/Rosetta_comet_probe_enters_hibernation_in_deep_space
266) “Rosetta triumphs at asteroid Lutetia,” ESA, July 10, 2010, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_triumphs_at_asteroid_Lutetia
267) “Rosetta reveals mysterious Lutetia,” ESA, Oct. 21, 2011, ESA, URL: http://sci.esa.int/rosetta/49543-rosetta-reveals-mysterious-lutetia/
268) “Rosetta Steins Flyby confirmed,” ESA Sept. 5, 2008, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_Steins_fly-by_confirmed
269) “Steins: A diamond in the sky,” ESA, Sept. 6, 2008, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Steins_A_diamond_in_the_sky
272) “The long trek,” ESA, URL: http://www.esa.int/Our_Activities/Space_Science/Rosetta/The_long_trek
273) “Hubble Assists Rosetta Comet Mission,” NewsRelease No: STScI-2003-26, Sept. 5, 2003, URL: http://hubblesite.org/newscenter/archive/releases/2003/26/image/a/
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).
Spacecraft Launch Sensor Complement Philae Mission Status References Back to Top | <urn:uuid:25f8d9b7-969c-4c6a-8256-39ba49e56c82> | CC-MAIN-2022-33 | https://www.eoportal.org/web/eoportal/satellite-missions/r/rosetta | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882570913.16/warc/CC-MAIN-20220809064307-20220809094307-00065.warc.gz | en | 0.922438 | 127,804 | 3.5 | 4 |
During the last major escape in 2015, almost a million people came to Germany. Whats become of you? Balance sheet of an integration. Verena Friederike Hasel
On one of the first days that smells of spring, Rasem Soufi parks the car in a forest clearing near the Saxon town of Mittweida. “Now she’s sleeping,” he says to his wife Rigerta, pointing to daughter Ruba, two years old. “You go out, I’ll stay with her.”
“No, you,” she says.
“No, you,” he says.
She laughs. “Which one of us loves her more?”
At the end both get out, but stay close to the car. The soufis often drive here, take folding chairs, coffee, biscuits, sometimes guests too, and sit with them on a tree stump, just as others ask their friends to sit at the garden table. | <urn:uuid:3dda393b-888b-48c5-97bd-c89b13ffee6b> | CC-MAIN-2022-33 | https://www.blogbookworld.com/integration-in-2015-around-one-million-refugees-came-to-germany-how-are-you-today-star-plus | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571502.25/warc/CC-MAIN-20220811194507-20220811224507-00065.warc.gz | en | 0.977619 | 211 | 1.8125 | 2 |
Americans were treated to an example of classic bullying recently when Elon Musk responded to a demand by U.S. Sen. Bernie Sanders “that the extremely wealthy pay their fair share.”
It’s hard to understand why Musk, the world’s richest man, took offense to Sanders’ comment. But that’s not the issue. It’s how he took offense.
Musk tweeted about Sanders: “I keep forgetting that you’re still alive. ”
Musk engaged in a personal attack on Sanders based upon a trait over which Sanders has no control. Sanders is 80 years of age.
It’s as if Musk, 50, was kicking sand in Sanders’ face.
Some may remember a body builder called Charles Atlas who developed an exercise program in the 1930s that spawned a memorable advertising campaign in which a muscular bully at a beach humiliates a skinny man who is walking with a beautiful date.Continue reading “Elon Musk Kicks Sand In Sanders’ Face” | <urn:uuid:90807526-513a-47bd-8544-ca0e117c3bc9> | CC-MAIN-2022-33 | https://www.abusergoestowork.com/tag/role-model/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.955315 | 220 | 1.632813 | 2 |
New Delhi: As the world still grapples with COVID-19, another infectious disease, Monkeypox, has raised its head. Over 15,000 cases of Monkeypox, endemic to parts of Africa, have been reported in several countries. There have been three cases so far in India.
With the recent detection of Monkeypox in children, there are concerns about the number of diseases that put children at risk of being affected. Two children in the United States have been diagnosed with monkeypox in the United States, health officials announced Friday. The younger age groups in the country are also at risk of diseases such as encephalitis, dengue and swine flu.
In Africa, monkeypox infections in children are more common, and doctors have noted higher proportions of severe cases and deaths in young children.
A matter of concern are:
An increasing number of children are also facing Dengue-induced hemophagocytic lymphohistiocytosis (HLH) syndrome in Pune. Doctors said three to four patients (children and adults) with dengue-induced HLH were being treated in major hospitals in Pune earlier this month.
Similarly, cases of dengue in children have also been reported in Karnataka and Telangana.
There has been an increasing number of Japanese encephalitis in Assam. It has risen to 38 this month, an official statement said on Friday. The disease mainly affects children and most adults in endemic countries have natural immunity after childhood infection, but individuals of any age can be affected, according to a report in News18.
According to the WHO, most infections are mild with fever and headache or no apparent symptoms. However, approximately 1 in 250 infections results in severe clinical disease and the incubation period is between 4 and 14 days.
In children, gastrointestinal pain and vomiting may be the dominant early symptoms. Severe illness is characterized by the rapid onset of high fever, headache, stiff neck, disorientation, coma, seizures, spastic paralysis, and eventually the death. The case fatality rate can reach 30% in people with symptoms of the disease.
There was an upward trend in H1N1 (swine flu) cases in Maharashtra in June. As of June 22, there were over 142 cases of swine flu, with three deaths in Kolhapur and two deaths each in Pune and Thane. Children under 5 years old are at higher risk of contracting the disease, especially those under 2 years old.
According to a report by The Indian Express, doctors have also noted swine flu in the pediatric population. “There is a mixed bag, with children detected with influenza, dengue and hand-foot-mouth disease – which is a mild contagious infection characterized by sores in the mouth and rashes on the hands and feet. This season we are seeing a share of H1N1 cases,” said Dr Lalwani, medical director of Bharati Hospital.
Kerala has witnessed the spread of tomato fever, a flu that mainly affects children under 5 years old.
As of last week, a small part of Kollam district had the virus but further spread is possible, officials have warned. While some reports claim that 80 cases of infection have been recorded in the state so far, others go as high as 100. Earlier, in May, the Minister of Health warned the population of the State not to panic as tomato fever is endemic in Kerala. .
What should parents do?
As children remain at risk of waterborne diseases, experts say they need to be kept hydrated. It is advisable to avoid oily and spicy foods during the monsoon and to eat meals rich in vitamin C and other nutrients. | <urn:uuid:44c0c54e-c88d-4d53-87f0-b9db1e0a3a3f> | CC-MAIN-2022-33 | https://joypeppers.com/threat-of-encephalitis-tomato-fever-that-threatens-children/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.970395 | 780 | 3.109375 | 3 |
Mark Zandi, Moody’s Chief Economist warns that the possibility of a recession transpiring in the next 12 to 18 months is uncomfortably high. He opines that the reality of a recession will happen if things do not turn out as planned.
According to the Moody analyst, a recession can be avoided if president Donald Trump does not escalate the tariff war with China, and if the UK arrives at a favorable solution to Brexit. Mr. Zandi also factors in the ability of central banks to maintain monetary stimulus. Still, he foresees that even if a recession does not occur, he predicts that the global economy will be much weaker, since he doubts if policymakers will be able to alter the current trend.
Although other economists do not agree with Mr. Zandi’s prediction about a forthcoming recession, they acknowledge the likely possibility of having a devitalized economy.
According to Professor Eswar Prasad of Cornell University, relying on consumer spending alone is not a sustainable condition. It has helped support growth in various economies but also faltered in other sectors. The professor stated that the key to economic growth is a set of policies aimed at reviving business and consumer confidence in order to boost investments.
Current Trend of Economic Activities in the U.S.
A recent poll conducted by Bankrate.com revealed that in the United States, most Americans have not actually recovered from the blows dealt by the 2008-2009 Great Recession. The latter event left many American households with fewer reasons to celebrate. Bankrate.com’s Sr. Economic Analyst, Mark Hamrick, said they found out that tens of millions of Americans are still struggling to even go back to their previous condition before the economy went south and took a turn for the worse.
Their latest survey showed that more than half of the American adults who went through the Great Recession said they experienced some kind of adverse financial impact. To which half of them said that they are even doing worse now, compared to how they were before the financial crisis of the previous decade took place
Such findings can be supported by the American Association of Retired Persons (AARP) data that shows more than half of American households today are without emergency savings.
Correspondingly, the U.S. Commerce Department came out with a report indicating that consumer retail spending fell for the first time since February of this year. Although August retail-spends went up by 0.6%, September saw a 0.3% drop; providing a clear sign that at present, the U.S. is experiencing slow economic growth.
Affected by the 0.3% slash in household spending are the online retailers, sellers of building materials and automobile dealers. According to the report, the decline in retail spending became apparent in February. | <urn:uuid:c8f85939-edcc-4032-8f13-730c96f0a7ca> | CC-MAIN-2022-33 | https://www.catastroika.com/moody-analytics-foresees-a-global-recession-in-the-next-12-to-18-months.php | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.963424 | 568 | 2.234375 | 2 |
The path to the attainment of the common good and to peace is above all that of respect for human life in all its many aspects, beginning with its conception, through its development and up to its natural end.
Peacemakers are those who love, defend and promote life in its fullness. True peacemakers, then, are those who love, defend and promote human life in all its dimensions, personal, communitarian and transcendent. Life in its fullness is the height of peace. Anyone who loves peace cannot tolerate attacks and crimes against life.
Those who insufficiently value human life and, in consequence, support among other things the liberalization of abortion, perhaps do not realize that in this way they are proposing the pursuit of a false peace. The flight from responsibility, which degrades human persons, and even more so the killing of a defenceless and innocent being, will never be able to produce happiness or peace. Indeed how could one claim to bring about peace, the integral development of peoples or even the protection of the environment without defending the life of those who are weakest, beginning with the unborn?
Every offence against life, especially at its beginning, inevitably causes irreparable damage to development, peace and the environment. Neither is it just to introduce surreptitiously into legislation false rights or freedoms which, on the basis of a reductive and relativistic view of human beings and the clever use of ambiguous expressions aimed at promoting a supposed right to abortion and euthanasia, pose a threat to the fundamental right to life.
There is also a need to acknowledge and promote the natural structure of marriage as the union of a man and a woman in the face of attempts to make it juridically equivalent to radically different types of union; such attempts actually harm and help to destabilize marriage, obscuring its specific nature and its indispensable role in society.
These principles are not truths of faith, nor are they simply a corollary of the right to religious freedom. They are inscribed in human nature itself, accessible to reason and thus common to all humanity. The Church’s efforts to promote them are not therefore confessional in character, but addressed to all people, whatever their religious affiliation. Efforts of this kind are all the more necessary the more these principles are denied or misunderstood, since this constitutes an offence against the truth of the human person, with serious harm to justice and peace.
Consequently, another important way of helping to build peace is for legal systems and the administration of justice to recognize the right to invoke the principle of conscientious objection in the face of laws or government measures that offend against human dignity, such as abortion and euthanasia.
WORLD PEACE DAY 2013 message, entitled “Blessed are the Peacemakers,” Pope Benedict XVI | <urn:uuid:f67dac90-b932-4fa5-bf27-f53ab4ca512d> | CC-MAIN-2022-33 | https://lifenetwork.eu/the-peacemakers/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.95405 | 571 | 2.515625 | 3 |
Mechanical engineering assistant professor eyes enhanced diagnosticsPosted on September 29, 2020
By improving measurements in extreme environments like aero-engine combustors and hypersonic aircraft flowpaths, Samuel Grauer hopes to fuel innovations
UNIVERSITY PARK, Pa. — With the goal of tackling complex measurement problems to improve technology, Samuel Grauer will join the Penn State College of Engineering’s Department of Mechanical Engineering (ME) as an assistant professor in January 2021.
Grauer is currently a postdoctoral fellow at the Georgia Institute of Technology.
Building on his previous work, he plans to employ statistical techniques, such as Bayesian data analysis and machine learning, at Penn State to glean crucial information from systems where the ability does not currently exist.
In particular, Grauer plans to target projects that require precise, multi-parameter imaging in extreme conditions, such as reconstructing interacting 3D flames in a practical, high-pressure combustor or characterizing the shock train in the internal flowpath of a hypersonic aircraft.
Grauer explained that many engineering systems feature complex measurement problems where any given sensor can only provide partial information about key variables such as pressure, temperature and velocity fields. In order to accelerate the design of these systems and improve their operation, it is necessary to combine information from multiple sensors and fundamental physical models to understand the system and monitor controls-relevant parameters.
“As a general matter, whenever you aim to push scientific and engineering frontiers — whether in heat transfer, fluid flow, combustion or other fields — progress is enabled by the ability to make measurements faster, more accurately, with greater precision, in more restrictive environments,” Grauer said. “Statistical analysis can provide the means to do so.”
Grauer also noted the growing emphasis placed on uncertainty quantification and data assimilation in ME, which are required to validate the numerical models used to tackle everyday design problems. The Bayesian framework used by Grauer in his research is a natural fit for these challenges.
As he prepares to begin his career at Penn State, Grauer said the breadth of the University’s expertise and platforms that support interdisciplinary work, especially the Institute for Computational and Data Sciences, will be critical in furthering his research goals.
“There are so many synergies I can tap into,” he said. “In ME, there are so many fantastic faculty members who are interested in the fundamental science and application of combustion and turbulence research, which is closely related to the diagnostic problems I’m interested in.”
Grauer hopes his natural passion for the material is translated to his students.
“I really enjoy the physics and coding aspects of ME,” he said. “By describing how these codes work, getting students excited about how you can use computational tools to solve complicated problems, I think my enthusiasm will come across pretty clearly.”
Whether the classes are virtual or in-person, he explained the ultimate goal is the same.
“It’s always important to engage with people and make connections; that is just the truth of the matter,” he said.
- Algorithm aims to alert consumers before they use illicit online pharmacies
- Scientists tap AI betting agents to help solve research reproducibility concerns
- Deep learning may help doctors choose better lung cancer treatments
- Using cues and actions to help people get along with artificial intelligence | <urn:uuid:cab6887a-ac54-427b-8cd6-30ef68ed6ef9> | CC-MAIN-2022-33 | https://www.icds.psu.edu/mechanical-engineering-assistant-professor-eyes-enhanced-diagnostics/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.933996 | 708 | 1.664063 | 2 |
Data from: Efficiency of lift production in flapping and gliding flight of swifts
Henningsson, Per; Hedenström, Anders; Bomphrey, Richard J. (2015), Data from: Efficiency of lift production in flapping and gliding flight of swifts, Dryad, Dataset, https://doi.org/10.5061/dryad.cn252
Many flying animals use both flapping and gliding flight as part of their routine behaviour. These two kinematic patterns impose conflicting requirements on wing design for aerodynamic efficiency and, in the absence of extreme morphing, wings cannot be optimised for both flight modes. In gliding flight, the wing experiences uniform incident flow and the optimal shape is a high aspect ratio wing with an elliptical planform. In flapping flight, on the other hand, the wing tip travels faster than the root, creating a spanwise velocity gradient. To compensate, the optimal wing shape should taper towards the tip (reducing the local chord) and/or twist from root to tip (reducing local angle of attack). We hypothesised that, if a bird is limited in its ability to morph its wings and adapt its wing shape to suit both flight modes, then a preference towards flapping flight optimization will be expected since this is the most energetically demanding flight mode. We tested this by studying a well-known flap-gliding species, the common swift, by measuring the wakes generated by two birds, one in gliding and one in flapping flight in a wind tunnel. We calculated span efficiency, the efficiency of lift production, and found that the flapping swift had consistently higher span efficiency than the gliding swift. This supports our hypothesis and suggests that even though swifts have been shown previously to increase their lift-to-drag ratio substantially when gliding, the wing morphology is tuned to be more aerodynamically efficient in generating lift during flapping. Since body drag can be assumed to be similar for both flapping and gliding, it follows that the higher total drag in flapping flight compared with gliding flight is primarily a consequence of an increase in wing profile drag due to the flapping motion, exceeding the reduction in induced drag. | <urn:uuid:a74ab68d-2ee0-46e4-a84f-3f482bee8383> | CC-MAIN-2022-33 | https://datadryad.org:443/stash/dataset/doi:10.5061/dryad.cn252 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.939947 | 464 | 3.015625 | 3 |
GAMETOCIDAL EFFECTS OF GIBBERELLIC ACID (GA3, GA4+7) ON COMMON ONION (ALLIUM CEPA L.)
The treatments were 10 and 15 respectively in 1978 and 1979; the 1 plant-unit was repeated 4 times in experiment 1 and 10 times in experiment 2.
Per each plant 3 umbels were maintained: 1 bagged to control the selfing rate in presence of blowflies, the second one bagged without blowflies, the third umbel free to open pollination. The data recorded for each umbel were: total number of flowers, number of seeded flowers, number of perfect seeds, weight and germination of perfect seeds. In the 1979 experiment, the pollen germination of the 'open' umbels was also tested.
The most efficient concentrations resulted to be 2 000 ppm for GA3 and 5 000 ppm for GA4+7 sprayed 10 times at 2–3 day intervals starting from the bolting stage. | <urn:uuid:74273e44-7714-417d-9c4a-d1447ba320f0> | CC-MAIN-2022-33 | https://www.ishs.org/ishs-article/111_10 | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.890195 | 249 | 2.5 | 2 |
The Split Second Effect
The Mechanism of How Equinus Can Damage the Human Foot and Ankle
James Amis, M.D.
J. Amis. The split second effect: The mechanism of how equines can damage the human foot and ankle. Frontiers in Surgery, 3(38), 2016.
The gastrocnemius contracture or equinus is well known to cause the majority of non-traumatic acquired foot and ankle problems. Till now the rapidly mounting evidence has only been an “association”. We know both equinus and let’s say, plantar fasciitis, most often coexist, but how are they related? In other words, how can a calf that is too tight cause all these problems? The split second effect describes in detail exactly how equinus, a calf that has become too tight, can silently and progressively damage an otherwise “normal” human foot.
The split second effect describes in detail exactly how equinus, a calf that has become too tight, can silently and progressively damage an otherwise “normal” human foot. The missing mechanism described by this effect is exactly why my colleagues and people in general have considered equinus as nothing more than a random association. This association can no longer be ignored.
- Where did we come from: the perfect human foot explains
- What about our unique bipedal (two leg walking) gait leaves us so vulnerable to these damages unlike quadrupeds (four leg walking)
- There are two critical parts to the split second effect mechanism:
- the ankle dorsiflexion component
- the knee extension component
- And all this damage occurs with every step in just 120 milliseconds or a 10th of a second: a split second | <urn:uuid:b396225b-4b0c-49c4-b0ed-30308445f3f2> | CC-MAIN-2022-33 | https://onestretch.com/the-split-second-effect/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.92345 | 364 | 2.828125 | 3 |
The Atlantic front East of Spitsbergen is also advancing Northwards. It is probably the slowest overall refreeze since 2012. There is likely some freezing but also a great daily variance in extent due to floating snow and possibly some melting, needing to be identified in specific areas. But here , the Eat Siberian bite seems unstopped in its ever slow advance, JAXA 15 to 29 September 2018 , the 15th being the messiest at the top left corner.
September 26 to October 1, amazing NASA captured melting at edge of Equinox North Pole darkness on what is the continuing advance of water towards the North from the East Siberian Sea quadrant, with strong evidence of melting:
These Goodbye Waves, the last phase of sea ice to water, changed in structure day by day September 29-30 and October 1, it was also certainly a mix of fusion physics requiring presence of a ship confirming and observing this directly. | <urn:uuid:d8473b18-703b-41ed-953d-84da497da375> | CC-MAIN-2022-33 | http://eh2r.blogspot.com/2018/09/towards-85-north-at-octobers-gate.html | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572581.94/warc/CC-MAIN-20220816211628-20220817001628-00065.warc.gz | en | 0.962306 | 189 | 2.125 | 2 |
What Is A Line Chart?
A lot of traders prefer the line chart to Japanese candlesticks or bar charts. For example, many traders who trade the stock market prefer to use line charts to see price movements. This is because they consider the closing price to be the most important price of all. The line chart basically consists of the closing price for each period.
Of all three charting methods, the line chart is the simplest and most easily understood by beginners. No specialised knowledge is required and they provide the 'big picture' of the current market. On the other hand, they lack a lot of information that is shown in bar charts, and especially candlestick charts. This includes the open, the high and the low price. For this reason, they can be misleading and traders should take care if they decide to use this type of charting method.
Whichever chart type you use, they demonstrate a simple and effective visual representation of th eprice of an asset over a specific period of time. Charts also illustrate supply and demand, and include all known news, plus current expectations of future news. In the case of any updates, the price will quickly adjust to this if it differs from these expectations.
Charts are popular because they are user-friendly and therefore simple to use for technical analysis. This means it is quite straightforward to analyse and identify movements and patterns that may repeat over time. For eample, a currency pair may have a certain tendancy to reach after a news even or some other economic data release.
A line chart connects the closing prices of a currency pair over a certain time period. As this is the only information shown, line charts are good at showing a picture of the overall trend because they reduce market noise.
Prices are plotted from left to right across the horizontal axis, which represents time. The vertical axis shows the price with the most recent price shown furthest to the right.
You can draw trendlines on a line chart which connect support and resistance points. A line chart shows trends the best, as this is simply the slope of the line. A steeper slope means prices are moving faster. Remember that a line chart only shows the closing price, so this ignores price fluctuations during the session.
Stay tuned for more Technical Analysis videos!
Disclaimer: This written/visual material is comprised of personal opinions and ideas. The content should not be construed as containing any type of investment advice and/or a solicitation for any transactions. It does not imply an obligation to purchase investment services, nor does it guarantee or predict future performance. FXTM, its affiliates, agents, directors, officers or employees do not guarantee the accuracy, validity, timeliness or completeness of any information or data made available and assume no liability for any loss arising from any investment based on the same.
Risk Warning: There is a high level of risk involved with trading leveraged products such as forex and CFDs. You should not risk more than you can afford to lose, it is possible that you may lose more than your initial investment. You should not trade unless you fully understand the true extent of your exposure to the risk of loss. When trading, you must always take into consideration your level of experience. If the risks involved seem unclear to you, please seek independent financial advice. | <urn:uuid:5be2c024-a9e5-4ed7-b2dc-67b90a64fd45> | CC-MAIN-2022-33 | https://www.forextime.com/education/videos/what-is-a-line-chart | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.931874 | 675 | 2.421875 | 2 |
pdf (2.1 MiB)
Save the Children Finland,Save the Children International,Save the Children Nepal
The Child Grant is a government of Nepal cash transfer programme for children under 5 years aiming to reduce underweight. Save the Children has developed a parenting programme for the families receiving this grant focusing on improving nutritional outcomes as well as social, emotional and cognitive development of children.
A Parenting Programme for the Child Grant is a guide for facilitators who have been trained to implement the 13 sessions that are included in this intervention. The annex to the guide contains key materials used in the sessions. | <urn:uuid:deb68ec5-b7e3-4e8d-b92c-ca01d59e2bca> | CC-MAIN-2022-33 | https://resourcecentre.savethechildren.net/document/parenting-programme-child-grant-facilitator-guide | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.896052 | 153 | 2.09375 | 2 |
„Access, as Tanya Titchkosky (2011) has observed, should not be understood simply as a bureaucratic procedure, but is about how spaces are experienced and lived as oriented toward bodies, with their differing capacities and incapacities. That we notice some modifications of spaces to make them more accessible reveals how spaces are already shaped around certain bodies. As Nirmal Puwar (2004) describes some bodies are perceived as “space invaders.” The modifications required for spaces to be opened to other bodies are often registered as willful impositions on those spaces.“
– Sara Ahmed on racism, ableism, misgendering and heterosexist assumptions. She argues that, if your body and your very being don’t fit into spaces (because they are already built and fit for others), you not only feel like an imposition, but you become an imposition to those spaces (and to others, who already fit in). Accomodations have to be made, so you can fit in. Therefore „you must be willing to minimize differences in order to fit in“.
Her sharp and sometimes metaphorical analyses of how individuals keep discriminatory structures and spaces alive by reproducing them in their mindsets and actions, are always an inspiration to me for taking responsibility and getting into action. | <urn:uuid:bdaeaddb-189d-46c7-9907-f88255e66907> | CC-MAIN-2022-33 | https://medienelite.de/2014/04/15/of-not-fitting-in-and-being-an-imposition/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573163.7/warc/CC-MAIN-20220818033705-20220818063705-00065.warc.gz | en | 0.954514 | 269 | 1.921875 | 2 |
Twitter targets writers. Since its inception, it has been known that the red social co-created by Jack Dorsey was not a place for everyone, and one of the main features that stops many people from using it more often is the character limit (today 280, before just 140). However, it seems that the platform is looking to open its horizons to attract those who like to express their ideas more extensively. The trial version just released Notesa new function that, if you are not one to tweet due to the many limitations that it implies, will surely interest you.
This new mechanic has been presented as a way to make longer texts than the traditional ones. tweets (or tweets, if you prefer to call them that). The benefit is not only the extension, but the versatility to share this type of content.
YOU CAN SEE: Twitter tests feeds that will reflect the most relevant conversations in its Community function
Twitter goes after bloggers with Notes
As announced on their official blog, Notes will allow you to create long texts of up to 2,500 wordsalso allowing these to be shared through tweets, and even through personalized links that anyone can see, even if they do not have an account on the platform.
At the moment, Notes is a test feature and nothing guarantees that it will materialize in the near or distant future in the native version of Twitter. At the moment it is only available to a limited selection of users on USA, Canada, United Kingdom y Ghana.
Twitter: Write for some, Notes for all
Of course, although only selected users from those countries will be the only ones who will be able to create Notes these days, the company has indicated that these can be viewed from the “majority of countries”.
YOU CAN SEE: How to know if an intruder entered your Twitter account?
Other users—those who won’t be able to make Notes, but will be able to see them—will have the ability to interact with them just like with a regular tweet: I like it, retweets, answers, etc. Will this functionality attract more writers and bloggers to the platform?
A small group of writers are helping us test Notes. They can be read on and off Twitter, by people in most countries. pic.twitter.com/IUVVkr2vnl
— Twitter Write (@TwitterWrite) June 22, 2022 | <urn:uuid:24910559-e2f1-4485-bf90-18b349aa9f2f> | CC-MAIN-2022-33 | https://www.world-today-news.com/does-twitter-become-a-blog-notes-feature-revealed-allowing-up-to-2500-words-social-networks-blog-social-networks/ | s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00065.warc.gz | en | 0.95857 | 485 | 1.546875 | 2 |
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