Why are Jupiter’s Galilean moons geologically active?
- Io is the most Volcanically active world in our solar system, Io get the heat from a process that happens on its interior called tidal heating, which arises from tidal forces exerted by Jupiter
- Europa is covered by water ice (because it is further away from Jupiter) but also has tidal heating which may create liquid oceans underneath the icy surface
- Gandymede and Callisto have weak tidal heating yet both moons show some geological activity and maybe under-surface oceans.