CO2 in Ganymede’s exosphere revealed by JWST
- 1CNRS/ Observatoire de Paris, LESIA, Meudon, France (dominique.bockelee@obspm.fr)
- 2Univ. Grenoble Alpes, CNRS, IPAG
- 3LATMOS/CNRS, Sorbonne Université, UVSQ
- *A full list of authors appears at the end of the abstract
Jupiter's icy moon Ganymede has been seen to have a tenuous exosphere produced by sputtering and possibly sublimation of water ice. To date, only hydrogen and oxygen have been detected in this exosphere (Barth et al., 1997; Hall et al. 1998; Roth et al. 2021). Here, we report on the first detection of CO2 in Ganymede's exosphere through observations of the 4.3 microns band with the NIRSPec/IFU instrument of the James Webb Space Telescope. Maps of the CO2 gas distribution over the leading and trailing hemispheres reveal an unexpected patchy CO2 exosphere. CO2 gas is observed over different terrain types, principally those exposed to intense Jovian irradiation, but also over some bright or dark terrains. The highest CO2 column density is found over the north polar cap of the leading hemisphere, which also has unique surface ice properties. The distribution and production mechanisms of CO2 vapor will be discussed using simulations of Ganymede's exosphere (Leblanc et al. 2017) and through comparison with maps of surface ice properties obtained with JWST (Bockelée-Morvan et al. 2024).
References:
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D. Bockelée-Morvan (1), O. Poch (2), F. Leblanc (3), V. Zakhrarov (1), E. Lellouch (1), Imke de Pater (4,5), T. Fouchet (1), P. Rodriguez-Ovalle (1), Lorenz Roth (6), F. Merlin (1), S. Duling (7), J. Saur (7), A. Masson (1), Patrick Fry (8), S. Trumbo (9), , E. Quirico (2), M. Brown (10), R. Cartwright (11), S. Cazaux (12), K. de Kleer (10), Z. Milby (10), A. Moingeon (2), A. Mura (13), B. Schmitt (2), F. Tosi (13). Affiliations: (1) LESIA, Observatoire de Paris, Université PSL, Sorbonne Universit\'e, Universit\'e Paris Cité, CNRS, 92195, Meudon, France, (2) Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France, (3) LATMOS/CNRS, Sorbonne Université, UVSQ, Paris, France, (4) Department of Astronomy, University of California, 22 Berkeley, CA 94720, USA, (5) Department of Earth and Planetary Science, University of California, 22 Berkeley, CA 94720, USA, (6) Space and Plasma Physics, KTH Royal Institute of Technology, Stockholm, Sweden (7) Institute of Geophysics and Meteorology, University of Cologne, Albertus Magnus Platz, 50923 Cologne, (8) Germany University of Wisconsin, Madison, WI, 53706 (9) Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY 14853, USA, (10) Division of Geological and Planetary Sciences, Caltech, Pasadena, CA 91125 USA, (11) Johns Hopkins University Applied Physics Laboratory, 11001 Johns Hopkins Rd. Laurel, MD 20723, (12) Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands, (13) Istituto Nazionale di AstroFisica – Istituto di Astrofisica e Planetologia Spaziali (INAF-IAPS), 00133 Rome, Italy.
How to cite: Bockelee-Morvan, D., Poch, O., Leblanc, F., Zakharov, V., and Lellouch, E. and the ERS Ganymede team: CO2 in Ganymede’s exosphere revealed by JWST, Europlanet Science Congress 2024, Berlin, Germany, 8–13 Sep 2024, EPSC2024-141, https://doi.org/10.5194/epsc2024-141, 2024.
