Which is the most interesting moon in the solar system?
There are some great answers here. Io, Titan, Enceladus, Europa –they are all very interesting. let me put in a vote for our own moon. for one thing, the moon/planet mass ratio for Moon/Earth is greater than for any other system, except Charon/Pluto (and Pluto is perhaps not really a planet anyway, but a Kuiper Belt Object). For another, having a moon at all is rare among the terrestrial planets: none for Mercury or Venus, and only two TINY moonlets for Mars. So the situation with Earth and Moon is very unusual. The Moon causes our tides and has effects of various kinds on planetary weather and life. So, it’s pretty interesting too. No life on it, though, at least not until a permanent base is established there.
