Hidden beneath the heavily cratered surface of Mimas, one of Saturn's smallest moons lies a secret: a global ocean of liquid water. This astonishing discovery, led by Dr. Valéry Lainey of the Observatoire de Paris-PSL and published in the journal Nature, reveals a "young" ocean formed just 5 to 15 million years ago, making Mimas a prime target for studying the origins of life in our solar system.