Water Ice on Mars and Europa

The discovery of subsurface water ice on Mars and the strong evidence for a global ocean on Europa have dramatically expanded the potential for extraterrestrial life within our solar system. The Phoenix lander confirmed water ice on Mars in 2008, found at depths of just 5 centimeters below the surface. Furthermore, data from the Galileo spacecraft showed Europa's magnetic field was 20% stronger than expected, providing compelling evidence for a saltwater ocean beneath its icy shell. These discoveries suggest that liquid water exists on at least two other worlds in our solar system, with Europa's ocean estimated to contain more than twice the volume of all of Earth's oceans.