A subsurface ocean is a layer of liquid water hidden beneath the frozen surface of an icy moon, kept liquid by tidal heating and insulated by the ice above. Several moons of Jupiter and Saturn, including Europa, Enceladus, and Mimas, harbor global oceans that may hold more water than all of Earth's seas. Because liquid water plus chemistry plus energy are the basic ingredients for life, these hidden seas are leading targets in the search for life beyond Earth.
Space Exploration · NASA · Ocean Worlds
Europa Clipper, the largest spacecraft NASA has ever sent to another world, is racing toward a Jupiter moon that may hide twice the water of all Earth...
Astrophysics · Planetary Science · Icy Moons
Mimas is 400 kilometers across, dominated by a crater so large the impact nearly broke it apart, and looks exactly like a frozen dead world should. In...