A volcano moon, the biggest moon in the solar system, the oldest moon in the solar system, and a moon with the best chance of hosting life are Jupiter’s four Galilean moons, named after Galileo who discovered them in 1610. Jupiter has 79 moons that we know of so far.

This is a long video and you may only want to watch the first 5 minutes. If you can find the time, it’s a fascinating deep dive into four of Jupiter’s moons