Jupiter Icy Moons Tidal Signatures and Ocean Mapping from Orbit

Abstract

Following the Galileo spacecraft encounters with Europa, Ganymede, and Callisto, evidence emerged suggesting that these Galilean moons of Jupiter may have liquid oceans underneath their icy shells. Detection of the oceans on one or all three moons will have profound implications on probability of life beyond the Earth. The icy satellites also have tidal environments that are among the strongest in the solar system. The leading time-varying tidal forcing term on the surface of Europa is at least 9 times larger than those on the inner planets. Tidal forcing on the surfaces of Ganymede and Callisto are about 10% and 7%, respectively, of that on Europa. Since a planetary body with internal fluid deforms more than an otherwise solid body, tidal measurements offer exciting opportunities to detect the oceans.