Your Personal Links Click the above link to go to the main Cosmiverse Page . Europa is the sixth known moon from the planet. Like the earth's moon, it ranks among the ten largest satellites in the solar system. Europa is made up mostly of silicate rock, rock containing compounds of silicon and oxygen. The surface of Europa is covered by water ice.
Gravitational forces keep Europa's interior warm.
The moon's orbit is not completely circular because Europa is pulled slightly by the gravity of the nearby moon Ganymede . As a result, Europa rocks as it orbits Jupiter and is squeezed and stretched slightly by the competing pulls of Jupiter and Ganymede. Rocks inside the moon rub together, producing heat that keeps the subsurface ice slushy or liquid. Europa has few craters. Its only distinctive features are orange lines that cover the surface but are concentrated near the equator.