A team of researchers lead by Dr. Federico Tosi of ‘Istituto Nazionale di Astrofisica’ (INAF) in Rome (of which Dr. Bianca Maria Dinelli, researcher of CNR-ISAC in Bologna, is part) used the high spatial resolution infrared measurements of the Italian instrument JIRAM (Jovian InfraRed Auroral Mapper) aboard the Nasa sonde Juno to study the surface composition of Ganimede, the largest of Jupiter Moons and of the natural satellites of the solar system. In this study, published on the journal Nature Astronomy, the researchers have found traces of chlorinated salts, and potentially carbonated salts, on top of organic compounds like aliphatic aldehydes on Ganimede’s surface. The potential presence of these compounds suggests that Ganimede, during its formation, had accumulated CO2 reach ices that could condense ammonia. As on the Earth and other planetary bodies, the presence of sodium indicates an interaction between liquid water and rocks. This interaction may have occurred at the beginning of Ganimede history, when mixture of ice and rocks melted, and water and other primordial volatile substances separated from rocks. Therefore, Ganimede could have had an ocean directly in contact with a mantle, and therefore it could have been inhabitable.
“Salts and organics on Ganymede’s surface from infrared observations by Juno/JIRAM”, Federico Tosi, Alessandro Mura, Alessandra Cofano, Francesca Zambon, Christopher R. Glein, Mauro Ciarniello, Jonathan I. Lunine, Giuseppe Piccioni, Christina Plainaki, Roberto Sordini, Alberto Adriani, Scott J. Bolton, Candice J. Hansen, Tom A. Nordheim, Alessandro Moirano, Livio Agostini, Francesca Altieri, Shawn M. Brooks, Andrea Cicchetti, Bianca Maria Dinelli, Davide Grassi, Alessandra Migliorini, Maria Luisa Moriconi, Raffaella Noschese, Pietro Scarica, Giuseppe Sindoni, Stefania Stefani and Diego Turrini,
Nature Astronomy, https://doi.org/10.1038/s41550-023-02107-5
Credit: Di NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill - Ganymede - Perijove 34 Composite, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=121027630