The gravity of the larger planets sent the comets hurtling toward the inner planets. After impact, the comet's ice may have been left on the planet or moon in liquid form. Europa, Callisto, and Ganymede. Magnetic readings taken by the Galileo probe indicate that there may have once been a salty liquid ocean on Ganymede's surface. Even our Moon has millions of tons of frozen water at the poles.
Scientists believe that the water was delivered by comet.
The ice could be turned into water for drinking, washing, and other needs. It could also be broken into its component hydrogen and oxygen to provide breathable air. More Links You can learn about water throughout our solar system in NASA's educational unit, Water in the Solar System . Riverdeep Interactive Learning Limited. All rights reserved.