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laboratory experiments that simulate the photo- and thermo-chemistry of extraterrestrial ices always lead to the formation of semi-refractory organic residues. these residues can be considered as laboratory analogs for the primitive organic matter incorporated into comets and asteroids. many specific organic molecules ... | the amino acid distribution in laboratory analogs of extraterrestrial organic matter: a comparison to cm chondrites |
large quantities of impact-related microspherules have been found in fine-grained sediments retained within seven out of nine, radiocarbon-dated, late pleistocene mammoth (mammuthus primigenius) and bison (bison priscus) skull fragments. the well-preserved fossils were recovered from frozen "muck" deposits (organic-ric... | impact-related microspherules in late pleistocene alaskan and yukon "muck" deposits signify recurrent episodes of catastrophic emplacement |
ices are omnipresent in cold regions in space on, e.g., comets, dust grains, transneptunian objects, surfaces of planets and their satellites. the dominant molecule in such ices is water, but also other small molecules or even complex organic molecules (coms) may be present. ionizing radiation (uv photons, electrons, i... | ion radiation in icy space environments: synthesis and radioresistance of complex organic molecules |
context. remote light scattering and thermal infrared observations provide clues about the physical properties of cometary and interplanetary dust particles. identifying these properties will lead to a better understanding of the formation and evolution of the solar system.aims: we present a numerical solution for the ... | scattering, absorption, and thermal emission by large cometary dust particles: synoptic numerical solution |
context. determining whether asteroids in cometary orbits (acos) are dormant or extinct comets is relevant for understanding the end-states of comets and the sizes of the comet population.aims: we intend to study the value distributions of effective diameter (d), beaming parameter (η), and visible geometric albedo (pv)... | size and albedo distributions of asteroids in cometary orbits using wise data |
we present high-resolution multiwavelength radio continuum images of the region within 150″ of sgr a*, revealing a number of new extended features and stellar sources in this region. first, we detect a continuous 2″ east-west ridge of radio emission, linking sgr a* and a cluster of stars associated with irs 13 n and ir... | sgr a* and its environment: low-mass star formation, the origin of x-ray gas and collimated outflow |
we describe the preparation and characterization (by uv-vis-ir spectroscopy) of a set of organic samples, stable at room temperature and above, that are part of the experiment "photochemistry on the space station (pss)" planned to be enclosed in the expose-r2 mission, which will be conducted on the expose-r facility. t... | organic samples produced by ion bombardment of ices for the expose-r2 mission on the international space station |
we calculate the momentum flux and pressure of ions measured by the ion composition analyzer (ica) on the rosetta mission at comet 67p/churyumov-gerasimenko. the total momentum flux stays roughly constant over the mission, but the contributions of different ion populations change depending on heliocentric distance. the... | momentum and pressure balance of a comet ionosphere |
the near-earth objects with low-jovian tisserand invariant (tj) represent about 9 per cent of the known objects orbiting in the near-earth space, being subject of numerous planetary encounters and large temperature variations. we aim to make a spectral characterization for a large sample of neos with tj ≤ 3.1. conseque... | spectral properties of near-earth objects with low-jovian tisserand invariant |
we evaluate numerically three different models for the parent comet of the kreutz family of sungrazers: (i) a centaur on a highly inclined or retrograde orbit that diffuse to the inner planetary region where it became a sungrazer (model 1). (ii) a parent comet injected from the oort cloud straight into a near-parabolic... | on the origin of the kreutz family of sungrazing comets |
aims: 2i/borisov (hereafter 2i) is the first visibly active interstellar comet observed in the solar system, allowing us for the first time to sample the composition of a building block from another system. we report on the monitoring of 2i with the ultraviolet-visual echelle spectrograph, the high-resolution optical s... | the similarity of the interstellar comet 2i/borisov to solar system comets from high-resolution optical spectroscopy |
far-ultraviolet observations of comets yield information about the energetic processes that dissociate the sublimated gases from their primitive surfaces. understanding which emission processes are dominant, their effects on the observed cometary spectrum, and how to properly invert the spectrum back to the composition... | fuv observations of the inner coma of 46p/wirtanen |
the rosetta mission to comet 67p/churyumov-gerasimenko has provided new data to better understand what comets are made of. the weak tensile strength of the cometary surface materials suggests that the comet is a hierarchical dust aggregate formed through gravitational collapse of a bound clump of small dust aggregates ... | thermal inertias of pebble-pile comet 67p/churyumov-gerasimenko |
ceres, the largest reservoir of water in the main belt, was recently visited by the dawn spacecraft, which revealed several areas bearing h2o-ice features. independent telescopic observations showed a water exosphere of currently unknown origin. we explore the effects of meteoroid impacts on ceres by considering the to... | erosion of volatiles by micrometeoroid bombardment on ceres and comparison to the moon and mercury |
one of the most striking and curious features of the small kuiper belt object (kbo), arrokoth, explored by new horizons is the bright, annular neck it exhibits at the junction between its two lobes. here we summarize past reported findings regarding the properties of this feature and then report new results regarding i... | some new results and perspectives regarding the kuiper belt object arrokoth's remarkable, bright neck |
we observed near-sun comet 323p/soho for the first time using ground and space telescopes. in late 2020 december, the object was recovered at subaru showing no cometary features on its way to perihelion. however, in our postperihelion observations, it developed a long narrow tail mimicking a disintegrated comet. the ej... | the lingering death of periodic near-sun comet 323p/soho |
large portions of comet 67p/churyumov-gerasimenko's northern hemisphere are blanketed by fallback material consisting of centimeter-sized particles termed the smooth terrains. observations from the rosetta mission show that the most drastic transient changes during 67p's 2015 perihelion passage occurred within a subset... | topographically influenced evolution of large-scale changes in comet 67p/churyumov-gerasimenko's imhotep region |
40 000 collected cometary particles have been identified on the 21 targets exposed by the cosima experiment on-board rosetta to the environment of comet 67p/churyumov-gerasimenko from 2014 august to 2016 september. the images of the targets where obtained by the cosima microscope (cosiscope, 13.95 μm pixel-1) with near... | optical properties of cometary particles collected by the cosima mass spectrometer on-board rosetta during the rendezvous phase around comet 67p/churyumov-gerasimenko |
the exospheres of small solar system bodies are now observed with high spatial resolution from space missions. interpreting infrared spectra of cometary gases obtained with the virtis experiment onboard the rosetta cometary mission requires detailed modeling of infrared fluorescence emission in optically thick conditio... | a radiative transfer model to treat infrared molecular excitation in cometary atmospheres |
our interpretation of the data returned by rosetta and other cometary missions is based on the predictions of theoretical models and the results of laboratory experiments. for example, kossacki et al. (2015) showed that 67p's surface hardness reported by spohn et al. (2015) can be explained by sintering. the present wo... | constraining the parameter space of comet simulation experiments |
aims: on july 3, 2015, an unprecedented increase in the magnetic field magnitude was measured by the rosetta spacecraft orbiting comet 67p/churyumov-gerasimenko (67p). this increase was accompanied by large variations in magnetic field and ion and electron density and energy. to our knowledge, this unusual event marks ... | unusually high magnetic fields in the coma of 67p/churyumov-gerasimenko during its high-activity phase |
in this study, the toxicity of vanadium (vci3) in allium cepa l. was studied. germination-related parameters, mitotic index (mi), catalase (cat) activity, chromosomal abnormalities (cas), malondialdehyde (mda) level, micronucleus (mn) frequency and superoxide dismutase (sod) activity were investigated. the effects of v... | dna fragmentation and multifaceted toxicity induced by high-dose vanadium exposure determined by the bioindicator allium test |
one of the most used rotary files in endodontics is niti files due to their superelastic properties. this property means that this instrument has extraordinary flexion that can adapt to large angles inside the tooth canals. however, these files lose their superelasticity and fracture during use. the aim of this work is... | effect of stabilized martensite on the long-term performance of superelastic niti endodontic files |
h2o:co, at concentrations of (3:2) and (10:1), was condensed on csi substrate at 15 k and irradiated with 46-mev 58ni11 + ion beam. radiolysis induced by fast heavy ions was analyzed by infrared spectroscopy (ftir). the formation of nine molecular species: co2, h2o2, hcooh, hco, h2co, 13co2, ch3oh, o3, and c3o2 was obs... | chemical reactions in h2o:co interstellar ice analogues promoted by energetic heavy-ion irradiation |
neonicotinoids are a relatively new type of insecticide to control a variety of pests. although they are generally considered to be safe, they can lead to harmful effects on human and environmental health. we aimed to investigate possible effects of common neonicotinoid insecticides (acetamiprid, clothianidin, imidaclo... | investigation of the genotoxic and cytotoxic effects of widely used neonicotinoid insecticides in hepg2 and sh-sy5y cells |
we present a photometric analysis of individual dust grains in the coma of comet 67p/churyumov-gerasimenko using osiris images taken from 2015 july to 2016 january. we analysed a sample of 555 taken during 18 d at heliocentric distances ranging between 1.25 and 2.04 au and at nucleocentric distances between 80 and 437 ... | post-perihelion photometry of dust grains in the coma of 67p churyumov-gerasimenko |
geoconservation is an increasingly widely adopted theoretical, practical and administrative approach to the protection of geological and geomorphological features of special scientific, functional, historic, cultural, aesthetic, or ecological value. protected sites on earth include natural rocky outcrops, shorelines, r... | exogeoconservation: protecting geological heritage on celestial bodies |
coal mining accounts for ∼12 % of the total anthropogenic methane (ch4) emissions worldwide. the upper silesian coal basin (uscb), poland, where large quantities of ch4 are emitted to the atmosphere via ventilation shafts of underground hard coal (anthracite) mines, is one of the hot spots of methane emissions in europ... | local-to-regional methane emissions from the upper silesian coal basin (uscb) quantified using uav-based atmospheric measurements |
prebiotic sugars are thought to be formed on primitive earth by the formose reaction. however, their formation is not fully understood and it is plausible that key intermediates could have formed in extraterrestrial environments and subsequently delivered on early earth by cometary bodies. 1,2-ethenediol, the enol form... | gas-phase identification of ( z )-1,2-ethenediol, a key prebiotic intermediate in the formose reaction |
when cosmic bodies of asteroidal and cometary origin, with a size from 20 to approximately 100 m, enter dense atmospheric layers, they are destroyed with a large probability under the action of aerodynamic forces and decelerated with the transfer of their energy to the air at heights from 20-30 to several kilometers. t... | determination of the height of the "meteoric explosion" |
the formation and main features of the fully nonlinear structure in a six-component dusty plasma system have been investigated using sagdeev potential approach. by means of pseudo-potential technique, the fluid equations describing the plasma system were diminished into a single nonlinear differential equation, called ... | formation of double-layers and super-solitons in a six-component cometary dusty plasma |
paraquat (pq) is a herbicide belonging to the group of bipyridylium salts. the objective of this study was to evaluate oxidative stress, dna damage, and cytotoxicity induced by paraquat in peripheral lymphocyte cells in vivo as well as pathological changes in various tissues. for this purpose, 28 male wistar rats in 6 ... | paraquat induced oxidative stress, dna damage, and cytotoxicity in lymphocytes |
es wird davon ausgegangen, dass das älteste weitgehend unveränderte material aus der frühphase des sonnensystems in form von eis und staub in kometen vorliegt. die esa‑mission rosetta trug daher mit philae eine landeeinheit, die die zusammensetzung des nukleus von komet 67p/churyumov‑gerassimenko in situ untersuchen so... | esas kometen‑mission rosetta – neu‑analyse der daten des cosac massenspektrometers |
an apparently asteroidal object found on images taken by h. b. zhao, b. li, g. zhaori, r. q. hong, and l. f. hu (and measured by zhao, li, h. lu, and g. zhaori) with the purple mountain observatory's 1.04-m f/1.8 schmidt telescope at its xuyi station (discovery observations tabulated below) has been found to show comet... | comet c/2017 e2 (xuyi) |
on 19 october 2014, comet c/2013 a1 (siding spring) had a close encounter with mars and deposited cometary dust particles into the martian atmosphere. we report a comprehensive analysis of the resulting meteor shower and its perturbation on mars' atmosphere and ionosphere. using mars atmosphere and volatile evolution/i... | the impact of comet siding spring's meteors on the martian atmosphere and ionosphere |
we present a historical account of advances in the study of the trans-neptunian (tn) population since pluto's discovery until present. early cosmogonic ideas about a tn belt or ring assumed that it was the leftover at the edge of a protoplanetary disk where densities were too low for the planetesimals to accumulate int... | introduction: the trans-neptunian zone: past, present and future |
the rosetta probe around comet 67p/churyumov-gerasimenko (67p) reveals an anisotropic dust distribution of the inner coma with jet-like structures. the physical processes leading to jet formation are under debate, with most models for cometary activity focusing on localized emission sources, such as cliffs or terraced ... | on the origin of inner coma structures observed by rosetta during a diurnal rotation of comet 67p/churyumov--gerasimenko. |
on 2019 august 30, a second interstellar object 2i/borisov was discovered 2 years after the discovery of the first known interstellar object, 1i/'oumuamua. can we send a spacecraft to this object, using existing and near-term technologies? in this paper we assess the technical feasibility of a near-term mission to 2i/b... | sending a spacecraft to interstellar comet 2i/borisov |
we report the detection of a dense ionized layer in the upper atmosphere of mars caused by the impact of dust from comet siding spring. the observations were made by the ionospheric radar sounder on the mars express spacecraft during two low-altitude passes approximately 7 h and 14 h after closest approach of the comet... | an ionized layer in the upper atmosphere of mars caused by dust impacts from comet siding spring |
aims: we study the meteoroid stream of the long-period comet c/1975 t2 (suzuki-saigusa-mori). this comet was suggested as the parent body of the established λ-ursae majorid meteor shower, no. 524.methods: we modeled 32 parts of a theoretical meteoroid stream of the parent comet considered. each of our models is charact... | modeling of the meteoroid stream of comet c/1975 t2 and λ-ursae majorids |
ginkgo biloba leaf extract has been shown to increase the incidence in liver tumors in mice in a 2-year bioassay conducted by the national toxicology program. in this study, the dna damaging effects of ginkgo biloba leaf extract and many of its constituents were evaluated in human hepatic hepg2 cells and the underlying... | ginkgo biloba leaf extract induces dna damage by inhibiting topoisomerase ii activity in human hepatic cells |
in this paper, we present the results of a morphological study performed on a sample of 28 ultracompact h ii (uc h ii) regions located near extended free-free emission, using radio continuum (rc) observations at 3.6 cm with the c and d very large array (vla) configurations, with the aim of determining a direct connecti... | ultracompact h ii regions with extended emission: the complete view |
we have studied the combined effect of the pressure anisotropies of lighter and heavier ions of opposite polarities on solitary waves in a plasma composed of these ions as well as kappa described electrons of solar and cometary origin. using the theory of chew, goldberger, and low (the cgl theory), the anisotropies of ... | effect of anisotropy of lighter and heavier ions on solitary waves in a multi-ion plasma |
in this work we provide measurements of the bidirectional reflectance in the vis-nir spectral range for a selection of laboratory samples to deduce parameters such as their visible spectrum, phase curve, hemispheric albedo and phase reddening. the aim is to simulate the reflectance of the comet nucleus in order to aid ... | bidirectional reflectance of laboratory cometary analogues to interpret the spectrophotometric properties of the nucleus of comet 67p/churyumov-gerasimenko |
nongravitational forces induced by sublimation of volatiles affect the rotational and orbital dynamics of comets. in addition to contributing to the improvement of ephemerides and of rotational models, nongravitational effects can help constrain the regional distribution and temporal evolution of cometary activity, whi... | nongravitational effects of cometary activity |
we report an apparent outburst of comet c/2014 un271 (bernardinelli-bernstein), as seen in las cumbres observatory 1-m telescope data. following our initial observations (kokotanekova et al. 2021, atel #14733), the comet had faded in brightness to r=19.57+/-0.04 mag, measured within a 4" radius aperture on 2021 sep 09.... | apparent outburst of comet c/2014 un271 (bernardinelli-bernstein) |
high-energy observations of the sun provide an opportunity to test the limits of our ability to accurately measure the properties of transiting exoplanets in the presence of stellar activity. here we insert the transit of a hot jupiter into continuous disk integrated data of the sun in lyα from nasa’s solar dynamics ob... | transiting the sun. ii. the impact of stellar activity on lyα transits |
radial transport of particles, elements and fluid driven by internal stresses in three-dimensional (3d) astrophysical accretion disks is an important phenomenon, potentially relevant for the outward dust transport in protoplanetary disks, origin of the refractory particles in comets, isotopic equilibration in the earth... | radial transport and meridional circulation in accretion disks |
comets are generally considered to contain the best-preserved material from the beginning of our planetary system, although the mechanism of their formation and subsequent evolution are still poorly understood. here we report the direct in situ measurement of h2o, co, and co2 by the ptolemy mass spectrometer onboard th... | low co/co2 ratios of comet 67p measured at the abydos landing site by the ptolemy mass spectrometer |
context. the esa rosetta mission investigated the environment of comet 67p/churyumov-gerasimenko (hereafter 67p) from august 2014 to september 2016. one of the experiments on board the spacecraft, the rosetta orbiter spectrometer for ion and neutral analysis (rosina) included a comet pressure sensor (cops) and two mass... | two years with comet 67p/churyumov-gerasimenko: h2o, co2, and co as seen by the rosina/rtof instrument of rosetta |
biosynthesis of gold nanoparticles of distinct geometric shapes with highly functional protein coats without additional capping steps is rarely reported. this study describes green synthesis of protein-coated gold nanoparticles for the first time from the edible, mycorrhizal fungus tricholoma crassum (berk.) sacc . the... | evaluating the antimicrobial, apoptotic, and cancer cell gene delivery properties of protein-capped gold nanoparticles synthesized from the edible mycorrhizal fungus tricholoma crassum |
ice in main belt asteroids and near-earth objects is of scientific and resource exploration interest, but small airless bodies gradually lose their ice to space by outward diffusion. here we quantitatively estimate the time it takes a porous airless body to lose all of its interior ice, based on an analytic solution fo... | ice loss from the interior of small airless bodies according to an idealized model |
near-earth objects (neos) owe their origins to both the main-belt asteroids and comets. they include (by definition) precursors for all meteorite samples. thus understanding neo connections is central to the modern study of small bodies in our solar system and serves as the principal focus of this chapter. herein we al... | the near-earth object population: connections to comets, main-belt asteroids, and meteorites |
we present the results of a long-term telescopic observation campaign of comet 21p/giacobini-zinner, parent body of the draconid meteor shower, spanning ∼240 days during its 2018 apparition. determinations of comet 21p’s dust production rate through the afρ parameter derived from these images show that the comet had a ... | dust production of comet 21p/giacobini-zinner throughout its 2018 apparition |
aims: we study the formation of the [oi] lines - that is, 5577.339 å (the green line), 6300.304 å and 6363.776 å (the two red lines) - in the coma of comets and determine the parent species of the oxygen atoms using the ratio of the green-to-red-doublet emission intensity, i5577/(i6300 + i6364), (hereafter the g/r rati... | forbidden oxygen lines at various nucleocentric distances in comets |
the paris carbonaceous chondrite represents the most pristine carbonaceous chondrite, providing a unique opportunity to investigate the composition of early solar system materials prior to the onset of significant aqueous alteration. a dual origin (namely from the inner and outer solar system) has been demonstrated for... | primordial heavy noble gases in the pristine paris carbonaceous chondrite |
modern techniques for planetary defense from comets and asteroids involve the deflection of the bolide via kinetic, gravitational, ablative, or radiative means. while potentially effective, none of these methods are capable of operating in a terminal interdiction mode wherethe threat is discovered with little time prio... | asteroid interception and disruption for terminal planetary defense |
carbon dioxide is one of the most abundant ices present in comets and is therefore important for understanding cometary composition and activity. we present analysis of observations of co2 and [o i] emission in three comets to measure the co2 abundance and evaluate the possibility of employing observations of [o i] emi... | the co2 abundance in comets c/2012 k1 (panstarrs), c/2012 k5 (linear), and 290p/jäger as measured with spitzer |
context. the binary asteroid 288p/(300163) is unusual both for its combination of wide-separation and high mass ratio and for its comet-like activity. it is not currently known whether there is a causal connection between the activity and the unusual orbit or if instead the activity helped to overcome a strong detectio... | component properties and mutual orbit of binary main-belt comet 288p/(300163) 2006 vw139 |
the detection of interstellar bodies passing near the sun offers the opportunity to observe not just objects similar to those in the solar system, but also unfamiliar objects without solar system analogues. here i show that asymptotic giant branch (agb) stellar evolution may lead to the creation, out of stardust, of su... | is interstellar object 2i/borisov a stardust comet? predictions for the post perihelion period |
we present the results of photometry, linear spectropolarimetry, and imaging circular polarimetry of comet c/2009 p1 (garradd) performed at the 6-m telescope bta of the special astrophysical observatory (russia) equipped by the multi-mode focal reducer scorpio-2. the comet was observed at two epochs post-perihelion: on... | polarimetry, photometry, and spectroscopy of comet c/2009 p1 (garradd) |
this paper presents a new method of determining the brightness and size of cometary nuclei that has been applied to the following 32 observed comets: 2p/encke, 29p/schwassmann-wachmann 1, 102p/shoemaker 1, 103p/hartley 2, 168p/hergenrother, 189p/neat, 260p/mcnaught, 315p/loneos, p/2012 nj (la sagra), p/2013 j2 (mcnaugh... | a new method of determining brightness and size of cometary nuclei |
comet c/2015 er61 (panstarrs) is a long-period oort cloud comet whose favorable approach to the inner parts of the solar system in 2017 april-may enabled us to characterize its primary volatile composition using the ishell spectrograph mounted on the 3 m nasa infrared telescope facility (irtf) on maunakea, hawaii. we u... | chemical composition of outbursting comet c/2015 er61 (panstarrs) |
gas-phase molecules in cometary atmospheres (comae) originate primarily from (1) outgassing by the nucleus, (2) sublimation of icy grains in the near-nucleus coma, and (3) coma (photo)chemical processes. however, the majority of cometary gases observed at radio wavelengths have yet to be mapped, so their production/rel... | gas sources from the coma and nucleus of comet 46p/wirtanen observed using alma |
modern ideas about objects approaching the earth are discussed. this population includes near-earth asteroids (neas), including potentially hazardous asteroids, short-period comets, meteoroid streams, and large sporadic meteoroids. an overview is given of the currently available information on the dynamic and physical ... | current knowledge of objects approaching the earth |
the problem of sky pollution with artificial light currently affects practically all branches that are related to the broadly understood environment. this is especially true for astronomical observations. this paper presents the results of measurements of the surface brightness of the night sky for the city of rzeszów ... | the increase in the surface brightness of the night sky and its importance in visual astronomical observations |
aims: to understand how the multitude of planetary systems that have been discovered come to be, we need to study systems at different evolutionary stages, with different central stars but also in different environments. the most challenging environment for planet formation may be the harsh uv radiation field of nearby... | an extended scattered light disk around at pyx. possible planet formation in a cometary globule |
any early or late dynamical instability in the outer solar system should have left their footprint on the trans-neptunian object (tno) populations. here, we study the collisional and dynamical evolution of such populations numerically by an updated version of alicandep, which suitably takes into account the onset of an... | collisional evolution of the trans-neptunian region in an early dynamical instability scenario |
meteor astronomy employs the atmosphere of the earth as a large area detector for 0.01-1000 mm meteoroids [1]. monitoring the atmospheres of other planets for meteor activity offers the opportunity to study the parent bodies of as-yet-undetected meteor showers, test ablation models under non-terrestrial conditions and ... | meteor phenomena in the atmosphere of venus |
the oort cloud is thought to be a reservoir of icy planetesimals and the source of long-period comets (lpcs) implanted from the outer solar system during the time of giant-planet formation. the abundance of rocky ice-free bodies is a key diagnostic of solar system formation models as it can distinguish between `massive... | direct measurement of decimetre-sized rocky material in the oort cloud |
the origin and evolution of gas in debris disks are still not well understood. secondary gas production from cometary material or a primordial origin have been proposed. so far, observations have mostly concentrated on co, with only a few c observations available. we overview the c and co content of debris disk gas and... | primordial or secondary? testing models of debris disk gas with alma |
it was recently proposed that there exists a "gateway" in the orbital parameter space through which centaurs transition to jupiter-family comets (jfcs). further studies have implied that the majority of objects that eventually evolve into jfcs should leave the centaur population through this gateway. this may be naivel... | the gateway from centaurs to jupiter-family comets: thermal and dynamical evolution |
european space agency's rosetta spacecraft at comet 67p/churyumov-gerasimenko (67p) was the first mission that accompanied a comet over a substantial fraction of its orbit. on board was the rosetta orbiter spectrometer for ion and neutral analysis mass spectrometer suite to measure the local densities of the volatile s... | volatiles in the h2o and co2 ices of comet 67p/churyumov-gerasimenko |
asteroid pairs are genetically related asteroids that recently separated (<few million years), but still reside on similar heliocentric orbits. a few hundred of these systems have been identified, primarily in the asteroid main belt. here, we studied a newly discovered pair of near-earth objects (neos): 2019 pr2 and... | recent formation and likely cometary activity of near-earth asteroid pair 2019 pr2-2019 qr6 |
over 200 molecules have been detected in multiple extraterrestrial environments, including glycolaldehyde (c2(h2o)2, gla), a two-carbon sugar precursor that has been detected in regions of the interstellar medium. its recent in situ detection on the nucleus of comet 67p/churyumov-gerasimenko and through remote observat... | cometary glycolaldehyde as a source of pre-rna molecules |
our aim was to analyze the variation of johnson-kron-cousins bvri color indexes of a sample with 22 active comets of various dynamic groups with the time, geometrical, observational and dynamical parameters. we performed photometric observations of 16 comets between 2010 and 2014, using robotic telescopes in three cont... | an analysis of the bvri colors of 22 active comets |
the atacama large aperture submillimeter telescope (atlast) is a concept for a 50m class single-dish telescope that will provide high sensitivity, fast mapping of the (sub-)millimeter sky. expected to be powered by renewable energy sources, and to be constructed in the atacama desert in the 2030s, atlast's suite of up ... | the atacama large aperture submillimetre telescope: key science drivers |
comets hold the key to the understanding of our solar system, its formation and its evolution, and to the fundamental plasma processes at work both in it and beyond it. a comet nucleus emits gas as it is heated by the sunlight. the gas forms the coma, where it is ionised, becomes a plasma, and eventually interacts with... | cometary plasma science |
context. a τ herculid meteor outburst or even storm was predicted to occur by several models around 5 ut on 31 may 2022 as a consequence of the break-up of comet 73p/schwassmann-wachmann 3 in 1995. the multi-instrument and multi-station experiment was carried out within the czech republic to cover possible earlier acti... | τ herculid meteor shower in the night of 30/31 may 2022 and the meteoroid properties |
approximation of the gravitational field of an irregular celestial body by the gravitational attraction field of four massive points is studied here in the framework of k-means method, known from the theory of pattern recognition. using this approach, the simplified models for gravitational fields of asteroid (1620) ge... | approximation for attraction field of irregular celestial bodies using four massive points |
recent detections of potentially habitable exoplanets around sunlike stars demand increased exploration of the physical conditions that can sustain life, by whatever methods available. insight into these conditions can be gained by considering the multiverse hypothesis; in a multiverse setting, the probability of livin... | multiverse predictions for habitability: planetary characteristics |
if a dust trail of bolide illuminated by the rays of the sun, which had just hid behind the horizon, it is visible as bright lanes in the night sky or in twilight. that's why we call its the twilight bolides. we have obtained several thousands of different tracks in the sky over kiev. therefore, we have identified a sp... | observations of twilight fireballs over kiev in 2013-2015 |
allyl isothiocyanate (aitc), a glucosinolates' hydrolytic product, was studied for its anti-insect potential against an economically important, destructive tephritid pest, zeugodacus cucurbitae (coquillett). the first, second and third instar maggots of the pest were fed on artificial diets amended with varied concentr... | appraisal of growth inhibitory, biochemical and genotoxic effects of allyl isothiocyanate on different developmental stages of zeugodacus cucurbitae (coquillett) (diptera: tephritidae) |
this work is intended to be the second publication in a series of papers reporting on the spectro-photometric properties of cometary analogues measured in the laboratory. herein, we provide in-situ hyperspectral imaging data in the 0.40-2.35 μm range from three sublimation experiments under simulated space conditions i... | bidirectional reflectance and vis-nir spectroscopy of cometary analogues under simulated space conditions |
one of the major discoveries of nasa's 1979-1991 pioneer venus orbiter is that the nightside ionosphere becomes filamentary at high altitude, forming comet-like tail rays. pioneer venus orbiter could not establish how much farther into the wake of venus tail rays extend, nor understand how they form. here we present pl... | a revised understanding of the structure of the venusian magnetotail from a high-altitude intercept with a tail ray by parker solar probe |
the paper presents two models that allow us to determine the change in the brightness of a comet during its outburst. the first of them (model a) is associated with the impact of individual scattering cross-sections on the brightness jump of the comet. the second (model b) is associated with the increase of sublimation... | two methods for determining the brightness change of a comet during its outburst |
the recent discovery of a hundred-kilometer-scale comet, c/2014 un271 (bernardinelli-bernstein), has provoked interest in the activity displayed by such a large body inbound from the oort cloud. we examine the serendipitous observation of un271 in long-cadence imaging by the tess satellite in 2018 and 2020, while berna... | no rotational variability in c/2014 un271 (bernardinelli-bernstein) at 23.8 au and 21.1 au as seen by tess |
we conducted a deep search for deuterated water (hdo) in the oort cloud comet c/2014 q2 (lovejoy), through infrared (ir) spectroscopy with nirspec at the keck observatory. in this letter, we present our detections of hdo and water (h2o) in comet lovejoy on 2015 february 4 (post-perihelion) after 1 hr integration on sou... | ground-based detection of deuterated water in comet c/2014 q2 (lovejoy) at ir wavelengths |
context. the luminous efficiency, τ, can be used to compute the pre-atmospheric masses of meteoroids from corresponding recorded meteor brightnesses. the derivation of the luminous efficiency is non-trivial and is subject to biases and model assumptions. this has led to greatly varying results in the last decades of st... | luminous efficiency of meteors derived from ablation model after assessment of its range of validity |
nitrogen-rich refractory organics are scarce phases recovered as a fraction of stratospheric idps and constitute the bulk of the organic matter of some ultracarbonaceous antarctic micrometeorites. they are likely formed under very specific conditions within a nitrogen-rich environment and may provide valuable clues on ... | formation of analogs of cometary nitrogen-rich refractory organics from thermal degradation of tholin and hcn polymer |
context. with only a few low- and high-mass star-formation regions studied in detail so far, it is unclear what role the enviroment plays in complex molecule formation. in this light, a comparison of relative abundances of related species between sources might be useful for explaining any observed differences.aims: we ... | tentative detection of ethylene glycol toward w51/e2 and g34.3+0.2 ⋆⋆⋆ |
the present study emphasizes the possible impact of coastal water quality on marine zooplankton community from six different sampling sites of south india (kalpakkam, nemmeli, muttukadu, kasimedu, ennore and kattupalli). water samples were collected in the sampling sites and physicochemical parameters were studied. the... | coastal water quality impact on community structure and genotoxicity of marine zooplankton |
ion acoustic waves were observed in the diamagnetic cavity of comet 67p/churyumov-gerasimenko by the rosetta spacecraft on 2015 august 3, when the comet was 1.25 au from the sun. wave spectra recorded by the langmuir probe (rpc-lap), peak near 200 hz, decrease for higher frequencies and reach the noise floor at approxi... | plasma waves confined to the diamagnetic cavity of comet 67p/churyumov-gerasimenko |
the knowledge about sulphur isotopic fractionation in volatile cometary species is limited as only measurements in five comets have been done and only for 34s/32s. the lack of information about the fractionation of 33s/32s makes it impossible to compare them with what is known from refractories. we present results of 3... | sulphur isotope mass-independent fractionation observed in comet 67p/churyumov-gerasimenko by rosetta/rosina |
context. here we describe a new model of the dust streams of comet 67p/churyumov-gerasimenko that has been developed using the interplanetary meteoroid environment for exploration (imex). this is a new universal model for recently created cometary meteoroid streams in the inner solar system.aims: the model can be used ... | characteristics of the dust trail of 67p/churyumov-gerasimenko: an application of the imex model |
the internal properties of porous and icy bodies in the solar system can be investigated by ground-penetrating radars (gprs), like the comet nucleus sounding experiment by radiowave transmission instrument on board the rosetta spacecraft which has sounded the interior of the nucleus of comet 67p/churyumov-gerasimenko. ... | characterization of the permittivity of controlled porous water ice-dust mixtures to support the radar exploration of icy bodies |
my journey in science began with the study of volcanic gases, sparking an interest in the origin, and ultimate fate, of the volatile elements in the interior of our planet. how did these elements, so crucial to life and our surface environment, come to be sequestered within the deepest regions of the earth, and what ca... | origins and early evolution of the atmosphere and the oceans |
the 1.5-km-wide, 40-m-deep, crater-like structure in the 10 ma old barda negra basaltic plateau in central argentina was discovered in the early 2000s. based on remote sensing surveys and on its morphological characteristics, similar to those of the barringer crater in arizona, the structure is described to be originat... | the formation of a giant collapse caprock sinkhole on the barda negra plateau basalts (argentina): magnetic, mineralogical and morphostructural evidences |
evolution of the surfaces of cometary nuclei is determined by the sublimation of ice. the rate of sublimation is commonly calculated using the simple hertz-knudsen formula, which should be corrected by a temperature dependent sublimation coefficient αs (kossacki et al., 1999; gundlach et al., 2011; kossacki and leliwa-... | sublimation of cometary ices in the presence of organic volatiles |
we report the beginning of activity for comet c/2015 er61 (panstarrs), the first instance of watching a long-period comet turn on. pre-discovery observations and observations from the neowise space telescope suggest that the nucleus is large, with a radius of rn∼ 9 km, assuming an albedo of 0.025. our photometric data ... | beginning of activity in long-period comet c/2015 er61 (panstarrs) |
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