Icy Moons

Some moons in the Solar System are covered in thick layers of ice and may have liquid oceans beneath their surfaces. Heat from tides or radioactivity may keep the water liquid. Scientists study these moons as places where life might exist.

Enceladus, a moon of Saturn, shoots water jets into space from cracks in its icy surface. Europa, a moon of Jupiter, is thought to have a deep ocean under its ice shell.