Yannis Bennacer; Olivier Mousis; Vincent Hue · 2025
Paper
The Galilean moons exhibit a decrease in bulk density with distance from Jupiter, which may reflect differences in evolutionary paths and water loss. Early in its history, Jupiter was more luminous and may have driven substantial atmospheric escape on Io and Europa. We investigate whether Io could have lost its water inventory while Europa retained its volatiles, assuming both moons initially accreted hydrous silicates. The formation and early thermal evolution of the protosatellites are modeled using an interior evolution model coupled with an atmospheric escape framework. Dehydration timescales and volatile losses for Io and Europa are computed during their early evolution, accounting for accretional heating from both satellitesimal and pebble accretion, as well as irradiation from Jupiter's primordial luminosity. Europa likely retained most of its volatiles under nearly all plausible formation and evolution scenarios, as large-scale dehydration would have taken place only after the first 10 Myr of its evolution. In contrast, Io was unlikely to lose a substantial amount of water through atmospheric escape and therefore probably accreted predominantly anhydrous silicates. If Europa initially accreted hydrous minerals, the present-day volatile contrast between Io and Europa could be explained by their relative locations with respect to the phyllosilicate dehydration line in the Jovian subnebula. Distinct evolutionary pathways or atmospheric escape processes alone appear insufficient to reproduce the observed differences.
Analysis
This study models the early evolution of Io and Europa to explain their divergent volatile inventories, suggesting differences in water loss due to their locations relative to Jupiter's primordial luminosity and the phyllosilicate dehydration line.
Discovery
Bastien Bodin; Daniel Cordier; Ashley Gerard Davies
Kurt D. Retherford; Philippa M. Molyneux; Thomas K. Greathouse; Michael W. Davis; G. Randall Gladstone; Steven C. Persyn; Maarten H. Versteeg; Mary F. Araujo; Fran Bagenal; Tracy M. Becker; Arnaud Beth; Ronald K. Black; Bertrand Bonfond; Shawn M. Brooks; Emma J. Bunce; Alain Carapelle; Steven Cortinas; Gregory J. Dirks; Bryan Esquivel; Paul D. Feldman; Sue Ferrell; Mark Ferris; Leigh N. Fletcher; Matthew A. Freeman; Marina Galand; Rohini S. Giles; Denis Grodent; Vincent Hue; Erica Johnson; Joshua A. Kammer; Cynthia Kempe; Laurent Lamy; Adrian Martin; Melissa A. McGrath; Edward G. Nerney; Carlos Nuñez; Zachary Olsen; Norman Pelletier; Brandon Perez; Kristian B. Persson; Eric Quémerais; Rick Raffanti; Ujjwal Raut; Ryan Rickerson; Lorenz Roth; Oswald H. W. Siegmund; John R. Spencer; Andrew J. Steffl; Bradley J. Trantham; John V. Vallerga; Todd J. Veach; Michael A. Velez; Brandon C. Walther; the JUICE-UVS Team
Nancy Y. Kiang; Christopher Gisriel; Robert E. Blankenship; Mary N. Parenteau; Hazel A. Barton; Oded Béjà; Anthony J. Burnetti; Ligia F. Coelho; Saleheh Ebadirad; Nathan M. Ennist; Yuka Fujii; Colin Gates; R. J. Graham; Keiichi Inoue; Betül Kaçar; Yu Komatsu; Émilie A. Laflèche; Nicoletta La Rocca; Elisabetta Liistro; Jonathan Lindsey; Timothy Lyons; Carolina A. Martinez-Gutierrez; Taro Matsuo; Victoria Meadows; Gary F. Moore; Massimo Olivucci; Kevin E. Redding; Edward W. Schwieterman; Tejinder Singh; Kenji Takizawa; Anna Grace Ulses; Junko Yano; Felisa Wolfe-Simon; Michael L. Wong; Anastasia G. Yanchilina
Aaron McKinnon; Neveda Naz
Peter M. Higgins; Weibin Chen; Oliver Warr; Lucas M. Fifer; Wanying Kang; Charles S. Cockell; Barbara Sherwood Lollar
Caroline Haslebacher; Emeline Bolmont; Marco Cilibrasi; Jonathan Grone; Nico Haslebacher; Ravit Helled; Mathilde Kervazo; Niels F. W. Ligterink; Christophe Lovis; Lucio Mayer; Lorenzo Obersnel; Rafael Ottersberg; Apurva V. Oza; C. H. Lucas Patty; Antoine Pommerol; Ganna Portyankina; Alyssa R. Rhoden; Leander Schlarmann; Yuhito Shibaike; Vishaal Singh; Audrey H. Vorburger; Peter Wurz
Source record