David I'll throw this into this post. Here on Earth the Moon and the
Sun moves the liquid water. On Ganymede it creates the volcanoes and
helps along with createring cracks its icy surface. Here you see an
object 665,000 miles away heateed up by the great gravitational force of
its massive parent. I read that Io Europa,and Ganymede were formed
around Jupiter while the planet itself was in the process of forming. I
find that needs a lot of thinking about. Bert PS One couold come up
with a theory when the sun and moon line up it could help volcano
activity here on Earth.(spring volano season) go figure