| Europa | |
|---|---|
 | |
| Description | |
| Satellite of | Jupiter |
| Orbital period | 85 hours |
| Diameter: | 3,122 km |
| Radius: | 1,561 km |
| Discovered | January 8, 1610 |
| Discoverer(s) | Galileo Galilei and Simon Marius |
Europa is the smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet. It is also the sixth-largest moon in the Solar System.
It's bright surface (roughly five times as reflective as the Moon), infrared water ice absorption bands, and the near absence of impact craters (only about five have been identified to date) indicate that the surface is ice rich and very young, perhaps only 30 million years old. Europa is covered by a water-ice shell no more than 150 kilometers thick. Calculations suggest that there could be liquid water at the base of this icy layer, leading to speculation that a primitive life form could have evolved in this dark, watery world. The thickness of the surface ice and the possible presence of liquid water have intrigued planetary scientists since the late 1970s.
| Moons of Jupiter |
|---|
| Ganymede • Callisto • Io • Europa |