Mimas, Saturn’s ‘Death Star’ moon may have a hidden ocean

“Mimas is a small moon, only about 400 kilometres in diameter, and its heavily cratered surface gave no hint of the hidden ocean beneath. This discovery adds Mimas to an exclusive club of moons with internal oceans, including Enceladus and Europa, but with a unique difference: its ocean is remarkably young, estimated to be only 5 to 15 million years old.” said Nick Cooper, a co-author of the study, in a press statement.

The ocean’s young age was determined by analysing Mimas’s tidal interactions with Saturn. An unexpected irregularity in its orbit suggested that the ocean formed recently. This implies that Mimas could provide a unique view into the early stages of ocean formation and the potential for life to emerge.

The discovery of the young ocean on Mimas suggest that even small and seemingly inactive moons can host hidden oceans that are capable of supporting conditions essential for life. This is especially fascinating, considering that scientists have found evidence of a key ingredient for life and a powerful source of energy that could fuel another one of Saturn’s icy moons — Enceladus.

The Mimas discovery was possible because of data from NASA’s Cassini spacecraft, which explored Saturn and its moons for over a decade. Analysing that data and finding subtle changes in Mimas’s orbit was what helped the scientists infer the presence of an ocean and even get an estimate for its size.