An ocean has been discovered on Saturn’s Mimas satellite

In the new work, the scientists analysed the orbital motion of Mimas in detail using data obtained by the Cassini probe, with a particular focus on perigee drift – the gradual shift of the closest point to Saturn in the orbit. It turned out that there is a global ocean hiding under the icy crust at a depth of 20-30 kilometres. The decrease in orbital eccentricity due to tidal interactions with the gas giant suggests that the ocean is probably less than 25 million years old and still evolving.

Modelling results show that the ocean-ice interface has only recently reached a depth of less than 30 kilometres (less than 2-3 million years ago), which is too short an interval for the surface to show signs of activity.