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| Titel |
The Coma of Comet 67P/Churyumov-Gerasimenko Pre- and Post- Equinox |
| VerfasserIn |
Nicolas Fougere, Kathrin Altwegg  , Jean-Jacques Berthelier, André Bieler, Dominique Bockelee-Morvan, Ursina Calmonte, Fabrizio Capaccioni, Mike Combi, Johan DeKeyser, Vincent Debout, Stephane Erard, Björn Fiethe, Gianrico Fillacchione, Uwe Fink, Stephen Fuselier, Tamas Gombosi, Kenneth Hansen, Myrtha Hässig, Zhenguang Huang, Lena Leroy, Cedric Leyrat, Alessandra Migliorini, Giuseppe Piccioni, Giovanna Rinaldi, Martin Rubin, Valeriy Tenishev, Gabor Toth, Chia-Yu Tzou, Yinsi Shou |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250136784
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| Publikation (Nr.) |
 EGU/EGU2016-17897.pdf |
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| Zusammenfassung |
| As the Rosetta spacecraft escorts comet 67P/Churyumov-Gerasimenko (67P) during its
journey in the Solar System, it monitors the evolution of the neutrals’ distribution in the coma
of 67P. Indeed, while the comet orbits around the Sun, the energy input received by
the different regions of the nucleus varies, directly impacting 67P’s outgassing
pattern.
We model the H2O, CO2, and CO coma of Comet 67P/Churyumov-Gerasimenko (67P) pre-
and post- equinox using a 3D Direct Monte-Carlo Simulation approach. The use of a kinetic
method enables us to model the coma from the nucleus’ surface to a few hundreds of
kilometers even in the regions where collisions cannot maintain a fluid regime. The activity at
the surface of the nucleus is described using a spherical harmonic expansion with 25 terms
constrained by ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis)
observations. The model outputs contain information about numerous macroscopic
parameters such as number densities, velocities, and temperatures of each species. Then, the
results from the simulations are integrated along the line of sight to be compared with
the remote sensing observations from the VIRTIS (Visible and Infrared Thermal
Imaging Spectrometer) instrument. The model shows a good agreement with the data,
giving a clear evidence of our understanding of the physics of the coma of comet
67P. |
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