The outer planets of the Solar System are swarmed by ice-wrapped moons. Some of these, such as Saturn’s moon Enceladus, are known to have oceans of liquid water between the ice shell and the rocky core and could be the best places in our solar system to look for extraterrestrial life. A new study published Nov. 24 in Nature Astronomy sheds light on what could be going on beneath the surface of these worlds and provides insights into how their diverse geologic features may have formed.