Cassini Reanalysis Puts Mimas in 6-Moon Ocean Club, Hiding Water 20-30 Kilometres Down
Updated
Updated · spacedaily.com · Jul 26
Cassini Reanalysis Puts Mimas in 6-Moon Ocean Club, Hiding Water 20-30 Kilometres Down
1 articles · Updated · spacedaily.com · Jul 26
Summary
A 2024 reanalysis of Cassini orbit and rotation data indicates Saturn’s moon Mimas likely holds a global ocean buried 20 to 30 kilometres beneath its icy crust.
The study argues that ocean probably formed less than 25 million years ago, making Mimas a strong sixth case for a present-day subsurface ocean in the outer Solar System.
Mimas stands out because its heavily cratered surface shows none of the fractures or plumes seen on Enceladus, suggesting an apparently inert moon can still conceal liquid water.
That finding broadens the roster beyond Europa, Ganymede, Callisto, Enceladus and Titan, while Triton and several Uranian moons remain plausible but unconfirmed candidates.
Archived mission data are driving the shift: Cassini ended in 2017, and upcoming tests from Europa Clipper in 2030 and ESA’s Juice in 2031 should sharpen ocean-world evidence further.