1
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Goetz C, Behar E, Beth A, Bodewits D, Bromley S, Burch J, Deca J, Divin A, Eriksson AI, Feldman PD, Galand M, Gunell H, Henri P, Heritier K, Jones GH, Mandt KE, Nilsson H, Noonan JW, Odelstad E, Parker JW, Rubin M, Simon Wedlund C, Stephenson P, Taylor MGGT, Vigren E, Vines SK, Volwerk M. The Plasma Environment of Comet 67P/Churyumov-Gerasimenko. Space Sci Rev 2022; 218:65. [PMID: 36397966 PMCID: PMC9649581 DOI: 10.1007/s11214-022-00931-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 10/20/2022] [Indexed: 06/04/2023]
Abstract
The environment of a comet is a fascinating and unique laboratory to study plasma processes and the formation of structures such as shocks and discontinuities from electron scales to ion scales and above. The European Space Agency's Rosetta mission collected data for more than two years, from the rendezvous with comet 67P/Churyumov-Gerasimenko in August 2014 until the final touch-down of the spacecraft end of September 2016. This escort phase spanned a large arc of the comet's orbit around the Sun, including its perihelion and corresponding to heliocentric distances between 3.8 AU and 1.24 AU. The length of the active mission together with this span in heliocentric and cometocentric distances make the Rosetta data set unique and much richer than sets obtained with previous cometary probes. Here, we review the results from the Rosetta mission that pertain to the plasma environment. We detail all known sources and losses of the plasma and typical processes within it. The findings from in-situ plasma measurements are complemented by remote observations of emissions from the plasma. Overviews of the methods and instruments used in the study are given as well as a short review of the Rosetta mission. The long duration of the Rosetta mission provides the opportunity to better understand how the importance of these processes changes depending on parameters like the outgassing rate and the solar wind conditions. We discuss how the shape and existence of large scale structures depend on these parameters and how the plasma within different regions of the plasma environment can be characterised. We end with a non-exhaustive list of still open questions, as well as suggestions on how to answer them in the future.
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Affiliation(s)
- Charlotte Goetz
- ESTEC, European Space Agency, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle-upon-Tyne, UK
| | - Etienne Behar
- Swedish Institute of Space Physics, Box 812, 981 28 Kiruna, Sweden
- Lagrange, OCA, UCA, CNRS, Nice, France
| | - Arnaud Beth
- Department of Physics, Umeå University, 901 87 Umeå, Sweden
| | - Dennis Bodewits
- Physics Department, Leach Science Center, Auburn University, Auburn, AL 36832 USA
| | - Steve Bromley
- Physics Department, Leach Science Center, Auburn University, Auburn, AL 36832 USA
| | - Jim Burch
- Southwest Research Institute, P.O. Drawer 28510, San Antonio, TX 78228-0510 USA
| | - Jan Deca
- Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, 3665 Discovery Drive, Boulder, CO 80303 USA
| | - Andrey Divin
- Earth Physics Department, St. Petersburg State University, Ulianovskaya, 1, St Petersburg, 198504 Russia
| | | | - Paul D. Feldman
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 USA
| | - Marina Galand
- Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ UK
| | - Herbert Gunell
- Department of Physics, Umeå University, 901 87 Umeå, Sweden
| | - Pierre Henri
- Lagrange, OCA, UCA, CNRS, Nice, France
- LPC2E, CNRS, Orléans, France
| | - Kevin Heritier
- Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ UK
| | - Geraint H. Jones
- UCL Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, RH5 6NT UK
- The Centre for Planetary Sciences at UCL/Birkbeck, Gower Street, London, WC1E 6BT UK
| | | | - Hans Nilsson
- Swedish Institute of Space Physics, Box 812, 981 28 Kiruna, Sweden
| | - John W. Noonan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85719 USA
| | - Elias Odelstad
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
| | | | - Martin Rubin
- Physikalisches Institut, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Cyril Simon Wedlund
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstr. 6, 8042 Graz, Austria
| | - Peter Stephenson
- Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ UK
| | | | - Erik Vigren
- Swedish Institute of Space Physics, Box 537, SE-751 21 Uppsala, Sweden
| | - Sarah K. Vines
- Johns Hopkins Applied Physics Laboratory, Laurel, MD 20723 USA
| | - Martin Volwerk
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstr. 6, 8042 Graz, Austria
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2
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Affiliation(s)
- Alexey Potapov
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Jena, Germany
| | - Martin McCoustra
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, UK
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3
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Marschall R, Skorov Y, Zakharov V, Rezac L, Gerig SB, Christou C, Dadzie SK, Migliorini A, Rinaldi G, Agarwal J, Vincent JB, Kappel D. Cometary Comae-Surface Links: The Physics of Gas and Dust from the Surface to a Spacecraft. Space Sci Rev 2020; 216:130. [PMID: 33184519 PMCID: PMC7647976 DOI: 10.1007/s11214-020-00744-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 09/28/2020] [Indexed: 06/04/2023]
Abstract
A comet is a highly dynamic object, undergoing a permanent state of change. These changes have to be carefully classified and considered according to their intrinsic temporal and spatial scales. The Rosetta mission has, through its contiguous in-situ and remote sensing coverage of comet 67P/Churyumov-Gerasimenko (hereafter 67P) over the time span of August 2014 to September 2016, monitored the emergence, culmination, and winding down of the gas and dust comae. This provided an unprecedented data set and has spurred a large effort to connect in-situ and remote sensing measurements to the surface. In this review, we address our current understanding of cometary activity and the challenges involved when linking comae data to the surface. We give the current state of research by describing what we know about the physical processes involved from the surface to a few tens of kilometres above it with respect to the gas and dust emission from cometary nuclei. Further, we describe how complex multidimensional cometary gas and dust models have developed from the Halley encounter of 1986 to today. This includes the study of inhomogeneous outgassing and determination of the gas and dust production rates. Additionally, the different approaches used and results obtained to link coma data to the surface will be discussed. We discuss forward and inversion models and we describe the limitations of the respective approaches. The current literature suggests that there does not seem to be a single uniform process behind cometary activity. Rather, activity seems to be the consequence of a variety of erosion processes, including the sublimation of both water ice and more volatile material, but possibly also more exotic processes such as fracture and cliff erosion under thermal and mechanical stress, sub-surface heat storage, and a complex interplay of these processes. Seasons and the nucleus shape are key factors for the distribution and temporal evolution of activity and imply that the heliocentric evolution of activity can be highly individual for every comet, and generalisations can be misleading.
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Affiliation(s)
- Raphael Marschall
- Southwest Research Institute, 1050 Walnut St, Suite 300, Boulder, CO 80302 USA
- International Space Science Institute (ISSI), Hallerstrasse 6, 3012 Bern, Switzerland
| | - Yuri Skorov
- Institut für Geophysik und extraterrestrische Physik, Technische Universität Braunschweig, Mendelssohnstr. 3, 38106 Braunschweig, Germany
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | | | - Ladislav Rezac
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Selina-Barbara Gerig
- Physikalisches Institut, University of Bern, Sidlerstr. 5, 3012 Bern, Switzerland
- NCCR PlanetS, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Chariton Christou
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS Scotland UK
| | - S. Kokou Dadzie
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS Scotland UK
| | | | | | - Jessica Agarwal
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Jean-Baptiste Vincent
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Planetenforschung, Rutherfordstrasse 2, 12489 Berlin, Germany
| | - David Kappel
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Planetenforschung, Rutherfordstrasse 2, 12489 Berlin, Germany
- Institute of Physics and Astronomy, University of Potsdam, Potsdam-Golm, Germany
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Potapov A, Jäger C, Henning T. Ice Coverage of Dust Grains in Cold Astrophysical Environments. Phys Rev Lett 2020; 124:221103. [PMID: 32567895 DOI: 10.1103/physrevlett.124.221103] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/14/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
Surface processes on cosmic solids in cold astrophysical environments lead to gas-phase depletion and molecular complexity. Most astrophysical models assume that the molecular ice forms a thick multilayer substrate, not interacting with the dust surface. In contrast, we present experimental results demonstrating the importance of the surface for porous grains. We show that cosmic dust grains may be covered by a few monolayers of ice only. This implies that the role of dust surface structure, composition, and reactivity in models describing surface processes in cold interstellar, protostellar, and protoplanetary environments has to be reevaluated.
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Affiliation(s)
- Alexey Potapov
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, 07743 Jena, Germany
| | - Cornelia Jäger
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, 07743 Jena, Germany
| | - Thomas Henning
- Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
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Filacchione G, Capaccioni F, Ciarniello M, Raponi A, Rinaldi G, De Sanctis MC, Bockelèe-Morvan D, Erard S, Arnold G, Mennella V, Formisano M, Longobardo A, Mottola S. An orbital water-ice cycle on comet 67P from colour changes. Nature 2020; 578:49-52. [PMID: 32025011 DOI: 10.1038/s41586-020-1960-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/05/2019] [Indexed: 01/27/2023]
Abstract
Solar heating of a cometary surface provides the energy necessary to sustain gaseous activity, through which dust is removed1,2. In this dynamical environment, both the coma3,4 and the nucleus5,6 evolve during the orbit, changing their physical and compositional properties. The environment around an active nucleus is populated by dust grains with complex and variegated shapes7, lifted and diffused by gases freed from the sublimation of surface ices8,9. The visible colour of dust particles is highly variable: carbonaceous organic material-rich grains10 appear red while magnesium silicate-rich11,12 and water-ice-rich13,14 grains appear blue, with some dependence on grain size distribution, viewing geometry, activity level and comet family type. We know that local colour changes are associated with grain size variations, such as in the bluer jets made of submicrometre grains on comet Hale-Bopp15 or in the fragmented grains in the coma16 of C/1999 S4 (LINEAR). Apart from grain size, composition also influences the coma's colour response, because transparent volatiles can introduce a substantial blueing in scattered light, as observed in the dust particles ejected after the collision of the Deep Impact probe with comet 9P/Tempel 117. Here we report observations of two opposite seasonal colour cycles in the coma and on the surface of comet 67P/Churyumov-Gerasimenko through its perihelion passage18. Spectral analysis indicates an enrichment of submicrometre grains made of organic material and amorphous carbon in the coma, causing reddening during the passage. At the same time, the progressive removal of dust from the nucleus causes the exposure of more pristine and bluish icy layers on the surface. Far from the Sun, we find that the abundance of water ice on the nucleus is reduced owing to redeposition of dust and dehydration of the surface layer while the coma becomes less red.
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Affiliation(s)
| | | | - Mauro Ciarniello
- INAF-IAPS, Institute for Space Astrophysics and Planetology, Rome, Italy
| | - Andrea Raponi
- INAF-IAPS, Institute for Space Astrophysics and Planetology, Rome, Italy
| | - Giovanna Rinaldi
- INAF-IAPS, Institute for Space Astrophysics and Planetology, Rome, Italy
| | | | - Dominique Bockelèe-Morvan
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Universitè, Université Paris Diderot Sorbonne Paris Cité, Meudon, France
| | - Stèphane Erard
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Universitè, Université Paris Diderot Sorbonne Paris Cité, Meudon, France
| | - Gabriele Arnold
- German Aerospace Center (DLR), Institute of Planetary Research, Berlin, Germany
| | - Vito Mennella
- INAF-Osservatorio Astronomico di Capodimonte, Naples, Italy
| | | | - Andrea Longobardo
- INAF-IAPS, Institute for Space Astrophysics and Planetology, Rome, Italy
| | - Stefano Mottola
- German Aerospace Center (DLR), Institute of Planetary Research, Berlin, Germany
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Rubin M, Engrand C, Snodgrass C, Weissman P, Altwegg K, Busemann H, Morbidelli A, Mumma M. On the Origin and Evolution of the Material in 67P/Churyumov-Gerasimenko. Space Sci Rev 2020. [PMID: 32801398 DOI: 10.1007/s11214-019-0625-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Primitive objects like comets hold important information on the material that formed our solar system. Several comets have been visited by spacecraft and many more have been observed through Earth- and space-based telescopes. Still our understanding remains limited. Molecular abundances in comets have been shown to be similar to interstellar ices and thus indicate that common processes and conditions were involved in their formation. The samples returned by the Stardust mission to comet Wild 2 showed that the bulk refractory material was processed by high temperatures in the vicinity of the early sun. The recent Rosetta mission acquired a wealth of new data on the composition of comet 67P/Churyumov-Gerasimenko (hereafter 67P/C-G) and complemented earlier observations of other comets. The isotopic, elemental, and molecular abundances of the volatile, semi-volatile, and refractory phases brought many new insights into the origin and processing of the incorporated material. The emerging picture after Rosetta is that at least part of the volatile material was formed before the solar system and that cometary nuclei agglomerated over a wide range of heliocentric distances, different from where they are found today. Deviations from bulk solar system abundances indicate that the material was not fully homogenized at the location of comet formation, despite the radial mixing implied by the Stardust results. Post-formation evolution of the material might play an important role, which further complicates the picture. This paper discusses these major findings of the Rosetta mission with respect to the origin of the material and puts them in the context of what we know from other comets and solar system objects.
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Affiliation(s)
- Martin Rubin
- Physikalisches Institut, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Cécile Engrand
- CNRS/IN2P3, IJCLab, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Colin Snodgrass
- Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ UK
| | | | - Kathrin Altwegg
- Physikalisches Institut, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Henner Busemann
- Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zurich, Zurich, Switzerland
| | | | - Michael Mumma
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd., Greenbelt, 20771 MD USA
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Levasseur-Regourd AC, Agarwal J, Cottin H, Engrand C, Flynn G, Fulle M, Gombosi T, Langevin Y, Lasue J, Mannel T, Merouane S, Poch O, Thomas N, Westphal A. Cometary Dust. Space Sci Rev 2018; 214:64. [PMID: 35095119 PMCID: PMC8793767 DOI: 10.1007/s11214-018-0496-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/16/2018] [Indexed: 05/15/2023]
Abstract
This review presents our understanding of cometary dust at the end of 2017. For decades, insight about the dust ejected by nuclei of comets had stemmed from remote observations from Earth or Earth's orbit, and from flybys, including the samples of dust returned to Earth for laboratory studies by the Stardust return capsule. The long-duration Rosetta mission has recently provided a huge and unique amount of data, obtained using numerous instruments, including innovative dust instruments, over a wide range of distances from the Sun and from the nucleus. The diverse approaches available to study dust in comets, together with the related theoretical and experimental studies, provide evidence of the composition and physical properties of dust particles, e.g., the presence of a large fraction of carbon in macromolecules, and of aggregates on a wide range of scales. The results have opened vivid discussions on the variety of dust-release processes and on the diversity of dust properties in comets, as well as on the formation of cometary dust, and on its presence in the near-Earth interplanetary medium. These discussions stress the significance of future explorations as a way to decipher the formation and evolution of our Solar System.
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Affiliation(s)
- Anny-Chantal Levasseur-Regourd
- Sorbonne Université; UVSQ; CNRS/INSU; Campus Pierre et Marie Curie, BC 102, 4 place Jussieu, F-75005 Paris, France, Tel.: + 33 144274875,
| | - Jessica Agarwal
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg, 3, D-37077, Göttingen, Germany
| | - Hervé Cottin
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Université Paris-Est Créteil et Université Paris Diderot, Institut Pierre Simon Laplace, 94000 Créteil, France
| | - Cécile Engrand
- Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS/IN2P3 Université Paris Sud - UMR 8609, Université Paris-Saclay, Bâtiment 104, 91405 Orsay Campus, France
| | - George Flynn
- SUNY-Plattsburgh, 101 Broad St, Plattsburgh, NY 12901, United States
| | - Marco Fulle
- INAF - Osservatorio Astronomico, Via Tiepolo 11, 34143 Trieste Italy
| | - Tamas Gombosi
- Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yves Langevin
- Institut dAstrophysique Spatiale (IAS), CNRS/Université Paris Sud, Bâtiment 121, 91405 Orsay France
| | - Jérémie Lasue
- IRAP, Université de Toulouse, CNRS, UPS, CNES, Toulouse, France
| | - Thurid Mannel
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria; Physics Institute, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Sihane Merouane
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg, 3, D-37077, Göttingen, Germany
| | - Olivier Poch
- Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
| | - Nicolas Thomas
- Physikalisches Institut, Universität Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Andrew Westphal
- Space Sciences Laboratory, U.C. Berkeley, Berkeley, California 94720-7450 USA
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O'D Alexander CM, McKeegan KD, Altwegg K. Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets. Space Sci Rev 2018; 214:36. [PMID: 30842688 PMCID: PMC6398961 DOI: 10.1007/s11214-018-0474-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 06/09/2023]
Abstract
Asteroids and comets are the remnants of the swarm of planetesimals from which the planets ultimately formed, and they retain records of processes that operated prior to and during planet formation. They are also likely the sources of most of the water and other volatiles accreted by Earth. In this review, we discuss the nature and probable origins of asteroids and comets based on data from remote observations, in situ measurements by spacecraft, and laboratory analyses of meteorites derived from asteroids. The asteroidal parent bodies of meteorites formed ≤4 Ma after Solar System formation while there was still a gas disk present. It seems increasingly likely that the parent bodies of meteorites spectroscopically linked with the E-, S-, M- and V-type asteroids formed sunward of Jupiter's orbit, while those associated with C- and, possibly, D-type asteroids formed further out, beyond Jupiter but probably not beyond Saturn's orbit. Comets formed further from the Sun than any of the meteorite parent bodies, and retain much higher abundances of interstellar material. CI and CM group meteorites are probably related to the most common C-type asteroids, and based on isotopic evidence they, rather than comets, are the most likely sources of the H and N accreted by the terrestrial planets. However, comets may have been major sources of the noble gases accreted by Earth and Venus. Possible constraints that these observations can place on models of giant planet formation and migration are explored.
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Affiliation(s)
- Conel M O'D Alexander
- Dept. Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015, USA. . Tel. (202) 478 8478
| | - Kevin D McKeegan
- Department of Earth, Planetary, and Space Sciences, University of California-Los Angeles, Los Angeles, CA 90095-1567, USA.
| | - Kathrin Altwegg
- Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
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9
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Meech KJ, Weryk R, Micheli M, Kleyna JT, Hainaut OR, Jedicke R, Wainscoat RJ, Chambers KC, Keane JV, Petric A, Denneau L, Magnier E, Berger T, Huber ME, Flewelling H, Waters C, Schunova-Lilly E, Chastel S. A brief visit from a red and extremely elongated interstellar asteroid. Nature 2017; 552:378-81. [PMID: 29160305 DOI: 10.1038/nature25020] [Citation(s) in RCA: 249] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 11/10/2017] [Indexed: 11/08/2022]
Abstract
None of the approximately 750,000 known asteroids and comets in the Solar System is thought to have originated outside it, despite models of the formation of planetary systems suggesting that orbital migration of giant planets ejects a large fraction of the original planetesimals into interstellar space. The high predicted number density of icy interstellar objects (2.4 × 10-4 per cubic astronomical unit) suggests that some should have been detected, yet hitherto none has been seen. Many decades of asteroid and comet characterization have yielded formation models that explain the mass distribution, chemical abundances and planetary configuration of the Solar System today, but there has been no way of telling whether the Solar System is typical of planetary systems. Here we report observations and analysis of the object 1I/2017 U1 ('Oumuamua) that demonstrate its extrasolar trajectory, and that thus enable comparisons to be made between material from another planetary system and from our own. Our observations during the brief visit by the object to the inner Solar System reveal it to be asteroidal, with no hint of cometary activity despite an approach within 0.25 astronomical units of the Sun. Spectroscopic measurements show that the surface of the object is spectrally red, consistent with comets or organic-rich asteroids that reside within the Solar System. Light-curve observations indicate that the object has an extremely oblong shape, with a length about ten times its width, and a mean radius of about 102 metres assuming an albedo of 0.04. No known objects in the Solar System have such extreme dimensions. The presence of 'Oumuamua in the Solar System suggests that previous estimates of the number density of interstellar objects, based on the assumption that all such objects were cometary, were pessimistically low. Planned upgrades to contemporary asteroid survey instruments and improved data processing techniques are likely to result in the detection of more interstellar objects in the coming years.
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Taylor MGGT, Altobelli N, Buratti BJ, Choukroun M. The Rosetta mission orbiter science overview: the comet phase. Philos Trans A Math Phys Eng Sci 2017; 375:rsta.2016.0262. [PMID: 28554981 PMCID: PMC5454230 DOI: 10.1098/rsta.2016.0262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/07/2017] [Indexed: 05/11/2023]
Abstract
The international Rosetta mission was launched in 2004 and consists of the orbiter spacecraft Rosetta and the lander Philae. The aim of the mission is to map the comet 67P/Churyumov-Gerasimenko by remote sensing, and to examine its environment in situ and its evolution in the inner Solar System. Rosetta was the first spacecraft to rendezvous with and orbit a comet, accompanying it as it passes through the inner Solar System, and to deploy a lander, Philae, and perform in situ science on the comet's surface. The primary goals of the mission were to: characterize the comet's nucleus; examine the chemical, mineralogical and isotopic composition of volatiles and refractories; examine the physical properties and interrelation of volatiles and refractories in a cometary nucleus; study the development of cometary activity and the processes in the surface layer of the nucleus and in the coma; detail the origin of comets, the relationship between cometary and interstellar material and the implications for the origin of the Solar System; and characterize asteroids 2867 Steins and 21 Lutetia. This paper presents a summary of mission operations and science, focusing on the Rosetta orbiter component of the mission during its comet phase, from early 2014 up to September 2016.This article is part of the themed issue 'Cometary science after Rosetta'.
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Affiliation(s)
| | - N Altobelli
- ESA/ESAC, 28692 Villanueva de la Cañada, Spain
| | - B J Buratti
- JPL/California Institute of Technology, Pasadena, CA 91109, USA
| | - M Choukroun
- JPL/California Institute of Technology, Pasadena, CA 91109, USA
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Hilchenbach M, Fischer H, Langevin Y, Merouane S, Paquette J, Rynö J, Stenzel O, Briois C, Kissel J, Koch A, Schulz R, Silen J, Altobelli N, Baklouti D, Bardyn A, Cottin H, Engrand C, Fray N, Haerendel G, Henkel H, Höfner H, Hornung K, Lehto H, Mellado EM, Modica P, Le Roy L, Siljeström S, Steiger W, Thirkell L, Thomas R, Torkar K, Varmuza K, Zaprudin B. Mechanical and electrostatic experiments with dust particles collected in the inner coma of comet 67P by COSIMA onboard Rosetta. Philos Trans A Math Phys Eng Sci 2017; 375:rsta.2016.0255. [PMID: 28554975 DOI: 10.1098/rsta.2016.0255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/12/2017] [Indexed: 05/25/2023]
Abstract
The in situ cometary dust particle instrument COSIMA (COmetary Secondary Ion Mass Analyser) onboard ESA's Rosetta mission has collected about 31 000 dust particles in the inner coma of comet 67P/Churyumov-Gerasimenko since August 2014. The particles are identified by optical microscope imaging and analysed by time-of-flight secondary ion mass spectrometry. After dust particle collection by low speed impact on metal targets, the collected particle morphology points towards four families of cometary dust particles. COSIMA is an in situ laboratory that operates remotely controlled next to the comet nucleus. The particles can be further manipulated within the instrument by mechanical and electrostatic means after their collection by impact. The particles are stored above 0°C in the instrument and the experiments are carried out on the refractory, ice-free matter of the captured cometary dust particles. An interesting particle morphology class, the compact particles, is not fragmented on impact. One of these particles was mechanically pressed and thereby crushed into large fragments. The particles are good electrical insulators and transform into rubble pile agglomerates by the application of an energetic indium ion beam during the secondary ion mass spectrometry analysis.This article is part of the themed issue 'Cometary science after Rosetta'.
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Affiliation(s)
- Martin Hilchenbach
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Henning Fischer
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Yves Langevin
- Institut d'Astrophysique Spatiale, CNRS/Université Paris Sud, Bâtiment 121, 91405 Orsay, France
| | - Sihane Merouane
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - John Paquette
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Jouni Rynö
- Finnish Meteorological Institute, Erik Palmenin aukio 1, PO Box 503, 00101 Helsinki, Finland
| | - Oliver Stenzel
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Christelle Briois
- Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, CNRS/Université d'Orléans, 3 Av. de la Recherche Scientifique, 45071 Orléans, France
| | - Jochen Kissel
- Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
| | - Andreas Koch
- von Hoerner und Sulger GmbH, Schlossplatz 8, 68723 Schwetzingen, Germany
| | - Rita Schulz
- ESA - ESTEC, Postbus 299, 2200AG Noordwijk, The Netherlands
| | - Johan Silen
- Finnish Meteorological Institute, Erik Palmenin aukio 1, PO Box 503, 00101 Helsinki, Finland
| | - Nicolas Altobelli
- Solar System Science Operation Division, ESA-ESAC, PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
| | - Donia Baklouti
- Institut d'Astrophysique Spatiale, CNRS/Université Paris Sud, Bâtiment 121, 91405 Orsay, France
| | - Anais Bardyn
- Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, CNRS/Université d'Orléans, 3 Av. de la Recherche Scientifique, 45071 Orléans, France
- LISA, UMR CNRS 7583, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre Simon Laplace, 94000 Créteil, France
| | - Herve Cottin
- LISA, UMR CNRS 7583, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre Simon Laplace, 94000 Créteil, France
| | - Cecile Engrand
- Centre de Sciences Nucléaires et de Sciences de la Matière - CSNSM, CNRS/IN2P3-Univ. Paris Sud (UMR8609), Université Paris-Saclay, Bat. 104, 91405 Orsay, France
| | - Nicolas Fray
- LISA, UMR CNRS 7583, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre Simon Laplace, 94000 Créteil, France
| | - Gerhard Haerendel
- Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany
| | - Hartmut Henkel
- Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, CNRS/Université d'Orléans, 3 Av. de la Recherche Scientifique, 45071 Orléans, France
| | - Herwig Höfner
- Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany
| | - Klaus Hornung
- Universität der Bundeswehr LRT-7, Werner Heisenberg Weg 39, 85577 Neubiberg, Germany
| | - Harry Lehto
- Department of Physics and Astronomy, Tuorla Observatory, University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland
| | - Eva Maria Mellado
- Universität der Bundeswehr LRT-7, Werner Heisenberg Weg 39, 85577 Neubiberg, Germany
| | - Paola Modica
- Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, CNRS/Université d'Orléans, 3 Av. de la Recherche Scientifique, 45071 Orléans, France
- LISA, UMR CNRS 7583, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre Simon Laplace, 94000 Créteil, France
| | - Lena Le Roy
- Center for Space and Habitability (CSH), University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Sandra Siljeström
- Department of Chemistry, Materials and Surfaces, SP Technical Research Institute of Sweden, PO Box 857, 50115 Borås, Sweden
| | - Wolfgang Steiger
- RC Seibersdorf Research GmbH Business Field Aerospace Technology, 2444 Seibersdorf, Austria
| | - Laurent Thirkell
- Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, CNRS/Université d'Orléans, 3 Av. de la Recherche Scientifique, 45071 Orléans, France
| | - Roger Thomas
- Finnish Meteorological Institute, Erik Palmenin aukio 1, PO Box 503, 00101 Helsinki, Finland
| | - Klaus Torkar
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria
| | - Kurt Varmuza
- Institute of Statistics and Mathematical Methods in Economics, Vienna University of Technology, Wiedner Hauptstrasse 7/105-6, 1040 Vienna, Austria
| | - Boris Zaprudin
- RC Seibersdorf Research GmbH Business Field Aerospace Technology, 2444 Seibersdorf, Austria
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Fulle M, Marzari F, Della Corte V, Fornasier S, Sierks H, Rotundi A, Barbieri C, Lamy PL, Rodrigo R, Koschny D, Rickman H, Keller HU, López-moreno JJ, Accolla M, Agarwal J, A’hearn MF, Altobelli N, Barucci MA, Bertaux J, Bertini I, Bodewits D, Bussoletti E, Colangeli L, Cosi M, Cremonese G, Crifo J, Da Deppo V, Davidsson B, Debei S, De Cecco M, Esposito F, Ferrari M, Giovane F, Gustafson B, Green SF, Groussin O, Grün E, Gutierrez P, Güttler C, Herranz ML, Hviid SF, Ip W, Ivanovski SL, Jerónimo JM, Jorda L, Knollenberg J, Kramm R, Kührt E, Küppers M, Lara L, Lazzarin M, Leese MR, López-jiménez AC, Lucarelli F, Mazzotta Epifani E, Mcdonnell JAM, Mennella V, Molina A, Morales R, Moreno F, Mottola S, Naletto G, Oklay N, Ortiz JL, Palomba E, Palumbo P, Perrin J, Rietmeijer FJM, Rodríguez J, Sordini R, Thomas N, Tubiana C, Vincent J, Weissman P, Wenzel K, Zakharov V, Zarnecki JC. EVOLUTION OF THE DUST SIZE DISTRIBUTION OF COMET 67P/CHURYUMOV–GERASIMENKO FROM 2.2 au TO PERIHELION. ACTA ACUST UNITED AC 2016; 821:19. [DOI: 10.3847/0004-637x/821/1/19] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Hilchenbach M, Kissel J, Langevin Y, Briois C, Hoerner HV, Koch A, Schulz R, Silén J, Altwegg K, Colangeli L, Cottin H, Engrand C, Fischer H, Glasmachers A, Grün E, Haerendel G, Henkel H, Höfner H, Hornung K, Jessberger EK, Lehto H, Lehto K, Raulin F, Roy LL, Rynö J, Steiger W, Stephan T, Thirkell L, Thomas R, Torkar K, Varmuza K, Wanczek K, Altobelli N, Baklouti D, Bardyn A, Fray N, Krüger H, Ligier N, Lin Z, Martin P, Merouane S, Orthous-daunay FR, Paquette J, Revillet C, Siljeström S, Stenzel O, Zaprudin B. COMET 67P/CHURYUMOV–GERASIMENKO: CLOSE-UP ON DUST PARTICLE FRAGMENTS. ACTA ACUST UNITED AC 2016; 816:L32. [DOI: 10.3847/2041-8205/816/2/l32] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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