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the hydrogen emission from meteors is assumed to originate mainly from the meteoroid composition, making it a potential tracer of h2o molecules and organic compounds. h α line was previously detected in individual fireballs, but its variation in a larger meteor data set and dependence on the dynamical origin and physic... | hydrogen emission from meteors and meteorites: mapping traces of h2o molecules and organic compounds in small solar system bodies |
the magnetic field of a host star can impact the orbit of a stellar partner, planet, or asteroid if the orbiting body is itself magnetic or electrically conducting. here, we focus on the instantaneous magnetic forces on an orbiting body in the limit where the dipole approximation describes its magnetic properties as we... | magnetic interactions in orbital dynamics |
on 2022 september 26, the dart spacecraft will impact the surface of dimorphos, the ~160 m size satellite of the binary near-earth asteroid (nea) (65803) didymos. what will be observed on the surfaces of both asteroids and at the dart impact site is largely unknown, beyond the details of didymos revealed by previous ar... | anticipated geological assessment of the (65803) didymos-dimorphos system, target of the dart-liciacube mission |
shock metamorphism of minerals in meteorites provides insights into the ancient solar system. calcite is an abundant aqueous alteration mineral in carbonaceous chondrites. return samples from the asteroids ryugu and bennu are expected to contain calcite-group minerals. although shock metamorphism in silicates has been ... | shock recovery with decaying compressive pulses: shock effects in calcite (caco3) around the hugoniot elastic limit |
the objective of the psyche magnetometry investigation is to test the hypothesis that asteroid (16) psyche formed from the core of a differentiated planetesimal. to address this, the psyche magnetometer will measure the magnetic field around the asteroid to search for evidence of remanent magnetization. paleomagnetic m... | the psyche magnetometry investigation |
we used laboratory analysis to investigate the effect of mineral albedo, as defined at 750 nm, on the midinfrared emissivity spectra of silicates under lunar environment conditions. optical darkening has long been recognized as an effect of space weathering on the visible-to-near-infrared spectra of the moon. however, ... | effects of albedo on the mir emissivity spectra of silicates for lunar comparison |
we present the physical and dynamical properties of the recently discovered active asteroid (248370) 2005qn173 (aka 433p). from our observations, we derived two possible rotation period solutions of 2.7 ± 0.1 and 4.1 ± 0.1 h. the corresponding light-curve amplitudes computed after correcting for the effect of coma are ... | photometric and dynamic characterization of active asteroid (248370) 2005qn173 |
the focus of this work is the current distribution of asteroids in co-orbital motion with venus, earth and jupiter, under a quasi-coplanar configuration and for a medium-term timescale of the order of 900 years. a co-orbital trajectory is a heliocentric orbit trapped in a 1:1 mean-motion resonance with a given planet. ... | on the co-orbital asteroids in the solar system: medium-term timescale analysis of the quasi-coplanar objects |
the thermal/impact histories of sixteen eucrite meteorites were investigated: three monomict eucrites (nwa 999, a-87272,87, and stannern), five polymict eucrites (nwa 1000, nwa 1666, nwa 5601, y-980066,100, and y-980255,100), three quench-textured, eucrite melt rocks (y-981646,21, y-981651,105, and mil 0766214), one eu... | bombardment history of asteroid 4 vesta recorded by brecciated eucrites: large impact event clusters at 4.50 ga and discreet bombardment until 3.47 ga |
we examine data from the murchison widefield array (mwa) in the frequency range 72-102 mhz for a field of view that serendipitously contained the interstellar object ‘oumuamua on 2017 november 28. observations took place with a time resolution of 0.5 s and a frequency resolution of 10 khz. based on the interesting but ... | a serendipitous mwa search for narrowband signals from ‘oumuamua |
the winonaites are primitive achondrites which are associated with the iab iron meteorites. textural evidence implies heating to at least the fe, ni-fes cotectic, but previous geochemical studies are ambiguous about the extent of silicate melting in these samples. oxygen isotope evidence indicates that the precursor ma... | a geochemical study of the winonaites: evidence for limited partial melting and constraints on the precursor composition |
asteroids are the remnants of the process by which planets formed from the protoplanetary disk. laboratory analyses of materials originating from asteroids give us the unique opportunity to reveal the formation history of our solar system about 4.6 billion years ago. to obtain surface regolith in the low-gravity and va... | cfd-dem simulation of gas-driven sampling on asteroid regolith: dependence of collected mass on gas ejection |
(16) psyche is the largest m-type asteroid in the main belt and the target of the nasa discovery-class psyche mission. despite gaining considerable interest in the scientific community, psyche's composition and formation remain unconstrained. originally, psyche was considered to be almost entirely composed of metal due... | constraining the regolith composition of asteroid (16) psyche via laboratory visible near-infrared spectroscopy |
on mars, structural loads and the low tensile strength of in-place martian binders make existing solutions for martian structures uneconomical because they are based on the terrestrial sources like inflatable units. here we address this issue by introducing and analyzing three innovative structural forms in accordance ... | martian buildings: structural forms using in-place sources |
the insoluble organic matter (iom) contained in carbonaceous chondrites has witnessed a diverse suite of processes possibly starting from the evolution of the parent molecular cloud down to the protosolar nebula and finally to asteroidal processes that occurred on the chondrites' parent bodies. laser desorption coupled... | unprecedented molecular diversity revealed in meteoritic insoluble organic matter: the paris meteorite's case |
active force generation in living organisms, which is mainly involved in actin cytoskeleton and myosin molecular motors, plays a crucial role in various biological processes. although the contractile properties of actomyosin have been extensively investigated, their dynamic contribution to a deformable membrane remains... | non-periodic oscillatory deformation of an actomyosin microdroplet encapsulated within a lipid interface |
lunar dust proved to be troublesome during the apollo missions. the powdery dust got into everything, abrading spacesuit fabric, clogging seals and other critical equipment. even inside the lunar module, apollo astronauts were exposed to this dust after they removed their dust coated spacesuits. the lunar dust is compr... | self-cleaning spacesuits for future planetary missions using carbon nanotube technology |
hazards due to near-earth objects (neos) continue to pose a threat to life on earth. while our capability for discovering neos has steadily progressed over the last three decades, physical characterization of a representative population has lagged behind. to test the operational readiness of the global planetary defens... | near-earth asteroid (66391) moshup (1999 kw4) observing campaign: results from a global planetary defense characterization exercise |
the south eastern arabian sea (seas) margin represents a tropical eastern boundary upwelling system, which is subjected to intense seasonal hypoxia in the continental shelf, and impingement of oxygen minimum zone (omz) along the continental slope. this paper provides the first comprehensive information on abundance, di... | diversity and distribution of echinoderms in the south eastern arabian sea shelf under the influence of seasonal hypoxia |
the asteroid polarimetric database (apd) is a collection of asteroid polarimetry results compiled by d.f. lupishko of karazin kharkiv national university, ukraine. it is intended to include most asteroid polarimetry available through november 15, 2021. | asteroid polametric database (apd) bundle v2.0 |
as we know that the sun is a source of radiation in our solar system, the other planets or asteroids absorb some of the radiations incident on it and some reflected back into the space, these reflected radiations are called albedo. the spacecraft is affected by both radiations i. e direct radiations as well as albedo. ... | a study of libration points in modified cr3bp under albedo effect when smaller primary is an ellipsoid |
the current aim of nasa's journey to mars is a stepwise approach towards landing humans on the red planet, culminating in a sustained presence. there are many recent studies on how this could be achieved in an evolvable and affordable manner. most architectures begin with crewed missions to phobos or mars orbit in the ... | cargo logistics for a notional mars base using solar electric propulsion |
oxygen-isotope ratios of olivine in type i (mgo-rich) and type ii (feo-rich) chondrules and olivine fragments in the matrix from the tagish lake meteorite (ungrouped c2) were measured to understand the characteristics of the formation environment of the tagish lake chondrules. of the 43 samples analyzed, 31 are mgo-ric... | oxygen-isotope systematics of chondrules and olivine fragments from tagish lake c2 chondrite: implications of chondrule-forming regions in protoplanetary disk |
in the lightcurve inversion process where asteroid's physical parameters such as rotational period, pole orientation and overall shape are searched, the numerical calculations of the synthetic photometric brightness based on different shape models are frequently implemented. lebedev quadrature is an efficient method to... | lebedev acceleration and comparison of different photometric models in the inversion of lightcurves for asteroids |
in this study the impact of land-sea breeze circulation and internal boundary layer (ibl) on the atmospheric dispersion of airborne effluent releases at the tropical coastal site kalpakkam is simulated using mesoscale model wrf and lagrangian particle dispersion model flexpart. simulations with wrf are conducted for ty... | simulation of atmospheric dispersion of airborne effluent releases at a tropical coastal site under sea-breeze circulation and internal boundary layer development |
we model radar scattering by planetary surfaces using a ray-optics algorithm that includes fresnelian reflection and refraction, diffuse scattering, and coherent backscattering. we enhance the realism of the ray-optics algorithm by using scattering particles that are geometrically representative of the surfaces and int... | radar scattering by planetary surfaces modeled with laboratory-characterized particles |
we study the collapse of pebble clouds with a statistical model to find the internal structure of comet-sized planetesimals. pebble-pebble collisions occur during the collapse, and the outcome of these collisions affects the resulting structure of the planetesimal. we expand our previous models by allowing the individu... | radially resolved simulations of collapsing pebble clouds in protoplanetary discs |
multiple-asteroid exploration with low-thrust propulsion requires the design of transfer trajectory and the selection of the visiting sequence, as well as the estimation of the propellant budget. to this end, this paper presents a method to generate transfer trajectories and visiting sequences rapidly using finite four... | fast preliminary design of low-thrust trajectories for multi-asteroid exploration |
the tagish lake carbonaceous chondrite exhibits a unique compositional heterogeneity that may be attributed to varying degrees of aqueous alteration within the parent body asteroid. previous analyses of soluble organic compounds from four tagish lake meteorite specimens (tl5b, tl11h, tl11i, tl11v) identified distinct d... | new insights into the heterogeneity of the tagish lake meteorite: soluble organic compositions of variously altered specimens |
the current work explores the interactions between asteroid fragments and the associated flow topology to motivate a physically consistent representation of the fragmentation process following a fragmentation event during atmospheric entry. multibody aerodynamic simulations run with computational fluid dynamics (cfd) s... | interactions between asteroid fragments during atmospheric entry |
in the framework of the near earth objects (neos) observational campaign carried out within the neoshield-2 project, we identify nine new small d-type asteroids with estimated diameter less than 600 m. the link with meteorites for this class of asteroids is weak and the best fit obtained is with the tagish lake meteori... | small d-type asteroids in the neo population: new targets for space missions |
the extension of human space exploration from a low earth orbit to a high earth orbit, then to moon, mars, and possibly asteroids is nasa's biggest challenge for the new millennium. integral to this mission is the effective, sufficient, and reliable supply of cryogenic propellant fluids. therefore, highly energy-effici... | an advance in transfer line chilldown heat transfer of cryogenic propellants in microgravity using microfilm coating for enabling deep space exploration |
we develop a simple scaling argument for frictional dissipation in rubble-pile asteroids, parameterized as an effective dissipation factor q. this scaling is combined with a prediction (goldreich, p., sari, r., 2009. tidal evolution of rubble piles. astrophys. j. 691, 54-60) for the tidal response amplitude, parameteri... | tidal dissipation in rubble-pile asteroids |
the site selection and certification processes for planetary landers equipped with hazard avoidance capability are reviewed. the prior (large-scale) 'landability' of the target areas determined from orbital remote sensing can be only a few tens of per cent (∼40 % for perseverance, ∼80-90 % for apollo 11 and 60-70 % for... | planetary landings with terrain sensing and hazard avoidance: a review |
context. meteoroids impacting terrestrial planets at high speed may have different effects. on bodies without atmospheres, such as the moon and mercury, they form impact craters and contribute to the gardening process through which the surface material is constantly mixed. the interaction of high-speed meteoroids with ... | asteroidal and cometary dust flux in the inner solar system |
we explore the use of spectropolarimetry as a remote sensing tool for asteroids in addition to traditional reflectance measurements. in particular, we are interested in possible relationships between the wavelength-dependent variation of linear polarization and the properties of the surfaces, including albedo and compo... | linear spectropolarimetry: a new diagnostic tool for the classification and characterization of asteroids. |
we present hubble space telescope observations of the active asteroid (and geminid stream parent) 3200 phaethon when at its closest approach to earth (separation 0.07 au) in 2017 december. images were recorded within ∼1° of the orbital plane, providing extra sensitivity to low surface brightness caused by scattering fr... | hubble space telescope observations of 3200 phaethon at closest approach |
context. recent studies have analyzed the dynamical evolution of outer small body populations under the effects of an eccentric inner massive perturber, which result from a planetary scattering event. these investigations suggest that such outer reservoirs are composed of particles on prograde and retrograde orbits, as... | the role of general relativity on icy body reservoirs under the effects of an inner eccentric jupiter |
we present the results of a numerical study to prepare for the remote sensing of asteroid 162173 ryugu (1999 ju3) using the hayabusa2 thermal infrared imager (tir). we simulated the thermal characteristics of the asteroid with a thermophysical model (tpm) using an ideal body with a smooth and spherical surface, and inv... | feasibility and accuracy of thermophysical estimation of asteroid 162173 ryugu (1999 ju3) from the hayabusa2 thermal infrared imager |
space capabilities play a crucial role in ensuring human security. one of the threats coming from space is the possible damage to our assets by an asteroid or comet impact. as demonstrated by the object entering the earth's atmosphere over chelyabinsk, russia, in february 2013, the threat of an asteroid or comet impact... | international coordination on planetary defence: the work of the iawn and the smpag |
the fascinating idea of shepherding asteroids for science and resource utilization is being considered as a credible concept in a not too distant future. past studies identified asteroids which could be efficiently injected into manifolds which wind onto periodic orbits around collinear lagrangian points of the sun-ear... | control of asteroid retrieval trajectories to libration point orbits |
small body missions can significantly benefit from deploying small landing systems onto the surface of the visited object. despite the potential benefit that they may bring, deployments of landers in small body environments may entail significant mission design challenges. this paper thus addresses the potential of bal... | a comparative reliability analysis of ballistic deployments on binary asteroids |
wd 1145+017 is a unique white dwarf system that has a heavily polluted atmosphere, an infrared excess from a dust disk, numerous broad absorption lines from circumstellar gas, and changing transit features, likely from fragments of an actively disintegrating asteroid. here, we present results from a large photometric a... | shallow ultraviolet transits of wd 1145+017 |
we present the first comprehensive thermal and rotational analysis of the second most distant trans-neptunian object (tnos) (225088) 2007 or10. we combined optical light curves provided by the kepler space telescope-k2 extended mission and thermal infrared data provided by the herschel space observatory. we found that ... | large size and slow rotation of the trans-neptunian object (225088) 2007 or10 discovered from herschel and k2 observations |
we revisited a mass ejection phenomenon that occurred in asteroid p/2010 a2 in terms of the dynamical properties of the dust particles and large fragments. we constructed a model assuming anisotropic ejection within a solid cone-shaped jet and succeeded in reproducing the time-variant features in archival observational... | anisotropic ejection from active asteroid p/2010 a2: an implication of impact shattering on an asteroid |
asteroids and comets 10-100 m in size that collide with earth disrupt dramatically in the atmosphere with an explosive transfer of energy, caused by extreme air drag. such airbursts produce a strong blastwave that radiates from the meteoroid's trajectory and can cause damage on the surface. an established technique for... | a numerical assessment of simple airblast models of impact airbursts |
we present a deep imaging and spectroscopic search for emission from (3200) phaethon, a large near-earth asteroid that appears to be the parent of the strong geminid meteoroid stream, using the 4.3 m lowell discovery telescope. observations were conducted on 2017 december 14-18 when phaethon passed only 0.07 au from th... | a deep search for emission from "rock comet" (3200) phaethon at 1 au |
space-based telescopes offer unparalleled opportunities for characterizing exoplanets, solar system bodies, and stellar objects. however, observatories in low-earth orbits (e.g., hubble, characterising exoplanets satellite, twinkle, and an ever-increasing number of cubesats) cannot always be continuously pointed at a t... | terminus: a versatile simulator for space-based telescopes |
planet nine is a hypothetical planet located well beyond pluto that has been proposed in an attempt to explain the observed clustering in physical space of the perihelia of six extreme trans-neptunian objects or etnos. the predicted approximate values of its orbital elements include a semimajor axis of 700 au, an eccen... | finding planet nine: a monte carlo approach |
we use seven year's worth of observations from the catalina sky survey and the siding spring survey covering most of the northern and southern hemisphere at galactic latitudes higher than 20° to search for serendipitously imaged moving objects in the outer solar system. these slowly moving objects would appear as stati... | a serendipitous all sky survey for bright objects in the outer solar system |
we have long known that water and hydroxyl are important components in meteorites and asteroids. however, in the time since the publication of asteroids iii, evolution of astronomical instrumentation, laboratory capabilities, and theoretical models have led to great advances in our understanding of h2o/oh on small bodi... | astronomical observations of volatiles on asteroids |
comets can exhibit non-gravitational accelerations caused by recoil forces due to anisotropic mass loss. so might active asteroids. we present an astrometric investigation of 18 active asteroids in search of non-gravitational acceleration. statistically significant (signal-to-noise ratio (s/n) > 3) detections are ob... | non-gravitational acceleration of the active asteroids |
the structural coefficient of restitution describes the kinetic energy dissipation upon low-velocity (~0.1 m/s) impact of a small asteroid lander, mascot, against a hard, ideally elastic plane surface. it is a crucial worst-case input for mission analysis for landing macot on a 1km asteroid in 2018. we conducted pendul... | experimental determination of the structural coefficient of restitution of a bouncing asteroid lander |
in this review presented at the royal society meeting, `cometary science after rosetta', i present an overview of studies of small solar system objects that exhibit properties of both asteroids and comets (with a focus on so-called active asteroids). sometimes referred to as `transition objects', these bodies are perha... | asteroid-comet continuum objects in the solar system |
recently published space-based observations of main-belt asteroids with the akari telescope provide a full description of the 3 μm band, related to the presence of oh bearing minerals. here, we use laboratory spectra of carbonaceous chondrites obtained under controlled atmosphere (ci,cm,co,cv,cr tagish lake) to derive ... | "water" abundance at the surface of c-complex main-belt asteroids |
carbonaceous meteorites are fragments of asteroids rich in organic material. in the forming solar nebula, parent bodies may have accreted organic materials resulting from the evolution of icy grains observed in dense molecular clouds. the major issues of this scenario are the secondary processes having occurred on aste... | exploring the link between molecular cloud ices and chondritic organic matter in laboratory |
we introduce a new method for analyzing sparse photometric data of asteroids and apply it to zwicky transient facility observations of the jupiter trojan asteroids. this method relies on the creation of a likelihood model that includes the probability distribution of rotational brightness variations at an unknown rotat... | zwicky transient facility observations of trojan asteroids: a thousand colors, rotation amplitudes, and phase functions |
the mission accessible near-earth objects survey aims to physically characterize sub-km near-earth objects (neos). we report the first photometric results from the survey that began in 2013 august. photometric observations were performed using 1-4 m class telescopes around the world. we present rotational periods and l... | the mission accessible near-earth objects survey (manos): first photometric results |
context. centaurs go around the sun between the orbits of jupiter and neptune. only a fraction of the known centaurs have been found to display comet-like features. comet 29p/schwassmann-wachmann 1 is the most remarkable active centaur. it orbits the sun just beyond jupiter in a nearly circular path. only a handful of ... | the active centaur 2020 mk4 |
an amateur astronomer in the modern world has the opportunity not only to make visual observations for own interest, but can make scientific astronomical observations and new discoveries in astronomy. in my example, as amateur astronomer and only through self-education, i inform about my discoveries: of the possible dw... | the contribution of the modern amateur astronomer to the science of astronomy |
in this paper, gmv as a major aocs (attitude orbit control system)/gnc (guidance, navigation and control) system provider presents its work on the development of a gnc system for a kinetic impact mission. asteroid impacts on earth are a known source of extinction and played an important role in the evolution of life on... | kinetic impactor for a short warning asteroid deflection |
aims: the orbit of the outer satellite alexhelios of (216) kleopatra is already constrained by adaptive-optics astrometry obtained with the vlt/sphere instrument. however, there is also a preceding occultation event in 1980 attributed to this satellite. here, we try to link all observations, spanning 1980-2018, because... | observed tidal evolution of kleopatra's outer satellite |
context. stellar occultation is a powerful technique that allows the determination of some physical parameters of the occulting object. the result depends on the photometric accuracy, the temporal resolution, and the number of chords obtained. space telescopes can achieve high photometric accuracy as they are not affec... | a stellar occultation by the transneptunian object (50000) quaoar observed by cheops |
abstract orbital systems are often self-organized and/or characterized by harmonic relations. inspired by music theory, we rewrite the geddes and king-hele (qjras, 24, 10-13, 1983) equations for mirror symmetries among the distances of the planets of the solar system in an elegant and compact form by using the 2/3rd po... | scaling, mirror symmetries and musical consonances among the distances of the planets of the solar system |
the discovery of activity emanating from asteroid (4015) wilson-harrington in 1950 (harris, 1950) prompted astronomers to realize that comet-like activity, such as comae and tails, is not limited to comets. fewer than 30 of these "active asteroids" have been discovered (chandler et al., 2018) in the last 70 years, yet ... | chasing tails: active asteroid, centaur, and quasi-hilda discovery with astroinformatics and citizen science |
to more thoroughly study the effects of radiative forces on the orbits of small, astronomical bodies, we introduce the yarkovsky effect into reboundx, an extensional library for the n-body integrator rebound. two different versions of the yarkovsky effect (the "full version" and the "simple version") are available for ... | the yarkovsky effect in reboundx |
context. in situ observations of small asteroids, such as itokawa, ryugu, and bennu, show that surfaces covered by boulders and coarse terrain are frequent on such bodies. regolith grain sizes have distributions on approximately mm and cm scales, and the behavior of such large grains in the very low-gravity environment... | regolith behavior under asteroid-level gravity conditions: low-velocity impacts into mm- and cm-sized grain targets |
first-order variational equations are widely used in n-body simulations to study how nearby trajectories diverge from one another. these allow for efficient and reliable determinations of chaos indicators such as the maximal lyapunov characteristic exponent (mle) and the mean exponential growth factor of nearby orbits ... | second-order variational equations for n-body simulations |
a nearly dynamically symmetric rigid body is considered. an approximation of this body by a system of two homogeneous balls is studied, such that the components of the euler-poinsot tensor of the original body and its approximation coincide up to the third order and the moments of inertia of the body are well approxima... | on the approximation of a nearly dynamically symmetric rigid body by two balls |
two primitive near-earth asteroids, (101955) bennu and (162173) ryugu, will be visited by a spacecraft with the aim of returning samples back to earth. since these objects are believed to originate in the inner main belt primitive collisional families (erigone, polana, clarissa, and sulamitis) or in the background of a... | compositional study of asteroids in the erigone collisional family using visible spectroscopy at the 10.4 m gtc |
in this study, equilibrium points and periodic orbits in the potential field of asteroids are investigated. we present the linearized equations of motion relative to the equilibrium points and characteristic equations. we find that the distribution of characteristic multipliers of periodic orbits around the equilibrium... | equilibrium points and periodic orbits in the vicinity of asteroids with an application to 216 kleopatra |
the breakup of the l-chondrite parent body (lcpb) in the mid-ordovician is the largest documented asteroid breakup event during the past 3 gyr. it affected earth by a dramatic increase in the flux of l-chondritic material and left prominent traces in both meteorite and sedimentary records. a precise constraint on the t... | absolute dating of the l-chondrite parent body breakup with high-precision u-pb zircon geochronology from ordovician limestone |
epithelial tissues (epithelia) remove excess cells through extrusion, preventing the accumulation of unnecessary or pathological cells. the extrusion process can be triggered by apoptotic signalling, oncogenic transformation and overcrowding of cells. despite the important linkage of cell extrusion to developmental, ho... | topological defects in epithelia govern cell death and extrusion |
the importance of comets for the origin of life on earth has been advocated for many decades. amino acids are key ingredients in chemistry, leading to life as we know it. many primitive meteorites contain amino acids, and it is generally believed that these are formed by aqueous alterations. in the collector aerogel an... | prebiotic chemicals--amino acid and phosphorus--in the coma of comet 67p/churyumov-gerasimenko |
images from the osiris scientific imaging system onboard rosetta show that the nucleus of 67p/churyumov-gerasimenko consists of two lobes connected by a short neck. the nucleus has a bulk density less than half that of water. activity at a distance from the sun of >3 astronomical units is predominantly from the neck... | on the nucleus structure and activity of comet 67p/churyumov-gerasimenko |
we present the first measurement of elliptic (v2) and triangular (v3) flow in high-multiplicity 3he +au collisions at √{sn n }=200 gev . two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in 3he +au and in p +p collisions and indicate that collective effects dominate ... | measurements of elliptic and triangular flow in high-multiplicity 3he +au collisions at √{sn n }=200 gev |
the rosetta spacecraft reached comet 67p/churyumov-gerasimenko (hereafter 67p/c-g) in august 2014 at an heliocentric distance of 3.6 a.u. and was then put in orbit around its nucleus to perform detailed observations. among the collected data are the images acquired by the osiris instrument up to the perihelion passage ... | the global shape, density and rotation of comet 67p/churyumov-gerasimenko from preperihelion rosetta/osiris observations |
context. the esa rosetta spacecraft (s/c) is tracking comet 67p/churyumov-gerasimenko in close vicinity. this prolonged encounter enables studying the evolution of the volatile coma composition.aims: our work aims at comparing the diversity of the coma of 67p/churyumov-gerasimenko at large heliocentric distance to stud... | inventory of the volatiles on comet 67p/churyumov-gerasimenko from rosetta/rosina |
cometary nuclei consist mostly of dust and water ice. previous observations have found nuclei to be low-density and highly porous bodies, but have only moderately constrained the range of allowed densities because of the measurement uncertainties. here we report the precise mass, bulk density, porosity and internal str... | a homogeneous nucleus for comet 67p/churyumov-gerasimenko from its gravity field |
the sample analysis at mars (sam) instrument on board the mars science laboratory curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of mars at gale crater. central to this task ... | organic molecules in the sheepbed mudstone, gale crater, mars |
the composition of the neutral gas comas of most comets is dominated by h2o, co and co2, typically comprising as much as 95 per cent of the total gas density. in addition, cometary comas have been found to contain a rich array of other molecules, including sulfuric compounds and complex hydrocarbons. molecular oxygen (... | abundant molecular oxygen in the coma of comet 67p/churyumov-gerasimenko |
'oumuamua (1i/2017 u1) is the first known object of interstellar origin to have entered the solar system on an unbound and hyperbolic trajectory with respect to the sun. various physical observations collected during its visit to the solar system showed that it has an unusually elongated shape and a tumbling rotation s... | non-gravitational acceleration in the trajectory of 1i/2017 u1 ('oumuamua) |
the virtis (visible, infrared and thermal imaging spectrometer) instrument on board the rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67p/churyumov-gerasimenko. the very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral s... | the organic-rich surface of comet 67p/churyumov-gerasimenko as seen by virtis/rosetta |
cometary ices are rich in co2, co and organic volatile compounds, but the carbon content of cometary dust was only measured for the oort cloud comet 1p/halley, during its flyby in 1986. the cometary secondary ion mass analyzer (cosima)/rosetta mass spectrometer analysed dust particles with sizes ranging from 50 to 1000... | carbon-rich dust in comet 67p/churyumov-gerasimenko measured by cosima/rosetta |
as well known, boltzmann-gibbs statistics is the correct way of thermostatistically approaching ergodic systems. on the other hand, nontrivial ergodicity breakdown and strong correlations typically drag the system into out-of-equilibrium states where boltzmann-gibbs statistics fails. for a wide class of such systems, i... | the standard map: from boltzmann-gibbs statistics to tsallis statistics |
we examine the evolution of the water production of comet 67p/churyumov-gerasimenko during the rosetta mission (2014 june-2016 may) based on in situ and remote sensing measurements made by rosetta instruments, earth-based telescopes and through the development of an empirical coma model. the derivation of the empirical... | evolution of water production of 67p/churyumov-gerasimenko: an empirical model and a multi-instrument study |
comets harbor the most pristine material in our solar system in the form of ice, dust, silicates, and refractory organic material with some interstellar heritage. the evolved gas analyzer cometary sampling and composition (cosac) experiment aboard rosetta’s philae lander was designed for in situ analysis of organic mol... | organic compounds on comet 67p/churyumov-gerasimenko revealed by cosac mass spectrometry |
we use the gaia dr2 distances of about 700 mid-infrared selected young stellar objects in the benchmark giant molecular cloud orion a to infer its 3d shape and orientation. we find that orion a is not the fairly straight filamentary cloud that we see in (2d) projection, but instead a cometary-like cloud oriented toward... | 3d shape of orion a from gaia dr2 |
context. the complex shape of comet 67p and its oblique rotation axis cause pronounced seasonal effects. irradiation and hence activity vary strongly.aims: we investigate the insolation of the cometary surface in order to predict the sublimation of water ice. the strongly varying erosion levels are correlated with the ... | insolation, erosion, and morphology of comet 67p/churyumov-gerasimenko |
the rosetta probe, orbiting jupiter-family comet 67p/churyumov-gerasimenko, has been detecting individual dust particles of mass larger than 10-10 kg by means of the giada dust collector and the osiris wide angle camera and narrow angle camera since 2014 august and will continue until 2016 september. detections of sing... | evolution of the dust size distribution of comet 67p/churyumov-gerasimenko from 2.2 au to perihelion |
measurements of midrapidity charged-particle multiplicity distributions, d nch/d η , and midrapidity transverse-energy distributions, d et/d η , are presented for a variety of collision systems and energies. included are distributions for au +au collisions at √{snn}=200 , 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 gev, cu ... | transverse energy production and charged-particle multiplicity at midrapidity in various systems from √{sn n}=7.7 to 200 gev |
a prevailing theory for the interstellar production of complex organic molecules (coms) involves formation on warm dust-grain surfaces, via the diffusion and reaction of radicals produced through grain-surface photodissociation of stable molecules. however, some gas-phase o-bearing coms, notably acetaldehyde (ch3cho), ... | formation of complex organic molecules in cold interstellar environments through nondiffusive grain-surface and ice-mantle chemistry |
the esa rosetta spacecraft followed comet 67p at a close distance for more than 2 yr. in addition, it deployed the lander philae on to the surface of the comet. the (surface) composition of the comet is of great interest to understand the origin and evolution of comets. by combining measurements made on the comet itsel... | organics in comet 67p - a first comparative analysis of mass spectra from rosina-dfms, cosac and ptolemy |
the origin of life is believed to have started with prebiotic molecules reacting along unidentified pathways to produce key molecules such as nucleosides. to date, a single prebiotic pathway to purine nucleosides had been proposed. it is considered to be inefficient due to missing regioselectivity and low yields. we re... | a high-yielding, strictly regioselective prebiotic purine nucleoside formation pathway |
context. the elemental depletion of interstellar sulfur from the gas phase has been a recurring challenge for astrochemical models. observations show that sulfur remains relatively non-depleted with respect to its cosmic value throughout the diffuse and translucent stages of an interstellar molecular cloud, but its ato... | modeling sulfur depletion in interstellar clouds |
the virtis (visible, infrared and thermal imaging spectrometer) instrument aboard the rosetta spacecraft has performed extensive spectral mapping of the surface of comet 67p/churyumov-gerasimenko in the range 0.3-5 μm. the reflectance spectra collected across the surface display a low reflectance factor over the whole ... | refractory and semi-volatile organics at the surface of comet 67p/churyumov-gerasimenko: insights from the virtis/rosetta imaging spectrometer |
observations of cometary nuclei have revealed a very limited amount of surface water ice, which is insufficient to explain the observed water outgassing. this was clearly demonstrated on comet 9p/tempel 1, where the dust jets (driven by volatiles) were only partially correlated with the exposed ice regions. the observa... | the diurnal cycle of water ice on comet 67p/churyumov-gerasimenko |
the phenix collaboration presents first measurements of low-momentum (0.4 <pt<3 gev /c ) direct-photon yields from au + au collisions at √{sn n}=39 and 62.4 gev. for both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields obs... | beam energy and centrality dependence of direct-photon emission from ultrarelativistic heavy-ion collisions |
the european space agency (esa) recently selected comet interceptor as its first `fast' (f-class) mission. it will be developed rapidly to share a launch with another mission and is unique, as it will wait in space for a yet-to-be-discovered comet. | the european space agency's comet interceptor lies in wait |
context. we present an investigation of the surface properties of areas on the nucleus of comet 67p/churyumov-gerasimenko.aims: we aim to show that transport of material from one part of the cometary nucleus to another is a significant mechanism that influences the appearance of the nucleus and the surface thermal prop... | redistribution of particles across the nucleus of comet 67p/churyumov-gerasimenko |
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