Ganymede
Ganymede is the third of the Galilean moons from Jupiter. It is the largest moon in the Solar system, bigger than the planet Mercury, almost 52% larger than the diameter of the Moon and with twice its mass. It is 77% the diameter of Mars. Ganymede's size made it a popular location for early science fiction authors looking for locations beyond Mars that might be inhabitable by humans. In reality, Ganymede is a cold, icy, cratered world with a vanishingly thin atmosphere.
Read more about this topic: Jupiter's Moons In Fiction