French researchers discover an underground ocean on Mimas, a moon of Saturn

“If there is one object in the solar system where we really did not expect to find liquid water, it is certainly Mimas“, welcomes Valery Lainey, the astronomer at the Paris-PSL observatory who led a study, published Wednesday February 7 in the journal Nature, which shows the existence of an underground ocean on this moon of Saturn, small satellite 400 kilometers in diameter, living until now a discreet life around the gas giant.

“From the exterior, Mimas has an extremely cratered surface, suggesting that the surface is very oldcontinues the astronomer. There is an absence of geological activity, therefore a priori no trace of geophysical activity in its interior and yet, this is the surprise, there is the formation of an ocean under the icy surface which is little nearly 20 to 30 kilometers thick“.

A recent appearance of the body of water

To reach this conclusion, it was necessary to compare data provided by the American probe Cassini, which observed Saturn and its suburbs until 2017, and numerical models describing the movement of Mimas in its orbit. This moon joins the four others already known in our solar system to have this type of internal ocean, with a little extra here, an undoubtedly recent appearance of this global water mass.

For Valery Lainey, “this means that the solar system is constantly evolving, and that places which seem uninhabitable can sometimes become so very late in the evolution of the system”. Habitability, a key element before considering any hypothetical emergence of a form of life in the Universe.