Moons
Hundreds of moons circle the planets, from Phobos — small enough to walk around in a day — to Ganymede, bigger than Mercury. Some hide oceans under ice, one erupts lava fountains, one has rain and rivers of methane. Here are the 20 major moons, each with a guide and a 3D model.
Watch Jupiter's moons orbit in 3DEarth· 1 known moons
One large companion that steadies our tilt, drives the tides and records the early Solar System.
Mars· 2 known moons
Two tiny, potato-shaped moons, possibly captured asteroids — or debris from an ancient impact.
Jupiter· 95 known moons
The four Galilean moons: a volcanic world, two ocean worlds and an ancient cratered one.
Saturn· 274 known moons
Icy moons with geysers, a two-tone world and Titan, the only moon with a thick atmosphere.
Uranus· 28 known moons
Five major moons orbiting on their side, named after characters from Shakespeare and Pope.
Neptune· 16 known moons
Triton, a captured world orbiting backwards, with nitrogen geysers on a frozen surface.