1. The largest moon in the solar system is __________.
2. The jovian moon with the most geologically active surface is _________.
3. Strong evidence both from surface features and magnetic field data support the existence of a subsurface ocean on ____________.
4. __________ is responsible for the tremendous volcanic activity on Io.
5. ___________ is the most distant of Jupiter's four Galilean moons.
6. The fact that Europa orbits Jupiter twice for every one orbit of Ganymede is an example of a(n) __________.