With 63 known natural satellites, Jupiter is the planet with the most moons. However, Jupiter may have other undetected moons. Jupiter's largest moon is Ganymede, which was named for the Greek cup bearer to the gods.
Ganymede, along with Io, Europa and Callisto, were the first four Jovian moons discovered by Galileo Galilei in 1610. Some other natural satellites of Jupiter are Thebe, Metis, Leda and Carme.
There are approximately 156 known natural satellites. Although Jupiter may have the most moons, Saturn, Uranus and Neptune also have many moons. Saturn has 47 known moons, while Uranus has 27 satellites. Earth has the least number of moons, with only one. Venus and Mercury do not have any moons.