Europa (moon)

Europa is a natural satellite (moon) of Jupiter. Being observable from Earth with common binoculars, it is one of the four Galilean moons. As such it is a planetary-mass moon; the smallest and least massive orbiting Jupiter, and slightly smaller and less massive than Earth's. Europa is an icy moon, and, of the three icy Galilean moons, the closest orbiting Jupiter. As a result, it exhibits a relatively young surface, driven by tidal heating.