The inner two Galilean satellites of Jupiter differ from the outer two by having
A) much higher average densities and almost crater-free surfaces.
B) almost the same average densities but much older, more heavily cratered surfaces.
C) much lower average densities and heavily cratered surfaces.
D) almost the same average densities but much younger, less-cratered surfaces.

Question

Quizplus · Accepted Answer

The inner two Galilean moons, Io and Europa, have higher average densities due to their composition (more rocky and metallic materials) and have relatively smooth, younger surfaces with fewer craters compared to the outer moons, Ganymede and Callisto, which are composed more of ice and have older, more heavily cratered surfaces.

The Inner Two Galilean Satellites of Jupiter Differ from the Outer