| Europa |
| Europa is the sixth satellite of Jupiter that is known today, as well as being the fourth largest, and the second of the Galilean moons. It is a little smaller than Earth's moon. It was discovered in 1610 by Galileo and Marius. The age is not able to be proved at this time. Europa was named for a Phoenician princess stolen for Crete by the god Zeus, who turned into a white bull. It is similar to Io in bulk composition to terrestrial planets, and made mosely of silicate rock. It has, unlike Io, a thin outer layer of ice. There is evidence that it may have a small metallic core. The moons surface is not like anything else in the solar system. It is very smooth, and there are very few features on it higher than a few hundred meters. Europa resembles images of sea ice on Earth. It is possible that there is a layer of liquid water underneath the surface, maybe up to 50 km deep. If this is true, it's the only place other than Earth where water exists in great quantities. Its most striking aspect is some dark streaks crossing over the entire globe. Some of the larger are about 20 km across. Galileo discovered that Europa has a weak magnetic field, about 1/4th that of Ganymede's. This brings evidence that there is a conducting material under the surface, most likely a salty ocean. Diameter: 3138 km Mass: 4.80e22 kg Orbit: 670,900 km from Jupiter. |