Next are the giant outer planets. They have lots of moons. Jupiter, for instance, has 53 moons! The most well-known are Io (pronounced eye-oh), Europa, and Callisto. Jupiter also has the biggest moon in our solar system, Ganymede. These moons are so big you can see them with just a pair of binoculars. read more
Introduction A solar system is a star and all of the objects that travel around it—planets, moons, asteroids, comets and meteoroids. read more