1
|
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 SCIENCE REVIEWS 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] [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.
Collapse
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
| |
Collapse
|
2
|
Mifsud DV, Kaňuchová Z, Ioppolo S, Herczku P, Traspas Muiña A, Sulik B, Rahul KK, Kovács STS, Hailey PA, McCullough RW, Mason NJ, Juhász Z. Ozone production in electron irradiated CO 2:O 2 ices. Phys Chem Chem Phys 2022; 24:18169-18178. [PMID: 35861183 DOI: 10.1039/d2cp01535h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The detection of ozone (O3) in the surface ices of Ganymede, Jupiter's largest moon, and of the Saturnian moons Rhea and Dione, has motivated several studies on the route of formation of this species. Previous studies have successfully quantified trends in the production of O3 as a result of the irradiation of pure molecular ices using ultraviolet photons and charged particles (i.e., ions and electrons), such as the abundances of O3 formed after irradiation at different temperatures or using different charged particles. In this study, we extend such results by quantifying the abundance of O3 as a result of the 1 keV electron irradiation of a series of 14 stoichiometrically distinct CO2:O2 astrophysical ice analogues at 20 K. By using mid-infrared spectroscopy as our primary analytical tool, we have also been able to perform a spectral analysis of the asymmetric stretching mode of solid O3 and the variation in its observed shape and profile among the investigated ice mixtures. Our results are important in the context of better understanding the surface composition and chemistry of icy outer Solar System objects, and may thus be of use to future interplanetary space missions such as the ESA Jupiter Icy Moons Explorer and the NASA Europa Clipper missions, as well as the recently launched NASA James Webb Space Telescope.
Collapse
Affiliation(s)
- Duncan V Mifsud
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, UK. .,Institute for Nuclear Research (Atomki), Debrecen H-4026, Hungary.
| | - Zuzana Kaňuchová
- Astronomical Institute, Slovak Academy of Sciences, Tatranská Lomnica SK-059 60, Slovakia.
| | - Sergio Ioppolo
- School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4NS, UK.
| | - Péter Herczku
- Institute for Nuclear Research (Atomki), Debrecen H-4026, Hungary.
| | - Alejandra Traspas Muiña
- School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4NS, UK.
| | - Béla Sulik
- Institute for Nuclear Research (Atomki), Debrecen H-4026, Hungary.
| | - K K Rahul
- Institute for Nuclear Research (Atomki), Debrecen H-4026, Hungary.
| | | | - Perry A Hailey
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, UK.
| | - Robert W McCullough
- Department of Physics and Astronomy, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK
| | - Nigel J Mason
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, UK.
| | - Zoltán Juhász
- Institute for Nuclear Research (Atomki), Debrecen H-4026, Hungary.
| |
Collapse
|
3
|
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 SCIENCE REVIEWS 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] [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.
Collapse
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
| |
Collapse
|
4
|
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 SCIENCE REVIEWS 2020; 216:102. [PMID: 32801398 PMCID: PMC7392949 DOI: 10.1007/s11214-020-00718-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 07/03/2020] [Indexed: 06/02/2023]
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.
Collapse
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
| |
Collapse
|
5
|
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 SCIENCE REVIEWS 2020. [PMID: 32801398 DOI: 10.1007/s11214-019-0625-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|