The Solar System has a new ocean

Mimas, a small moon of Saturn, turns out to have an ocean beneath its icy surface — despite looking too geologically inert to have water sloshing inside. The fact that unexceptional Mimas has an ocean means that “you could have liquid water almost anywhere”, says astronomer Valéry Lainey. And that means a greater chance of extraterrestrial life somewhere: interactions between a buried ocean and a moon’s rocky core could generate enough chemical energy to sustain living organisms.