what is the largest moon in the solar system?

The largest moon in the solar system is Ganymede, which orbits the planet Jupiter. Ganymede has a diameter of about 5,270 kilometers (3,275 miles), making it even larger than the planet Mercury. It is unique for having its own magnetic field and a potential subsurface ocean that may contain more water than all of Earth's oceans combined. Ganymede is also the most massive moon in the solar system and is larger by volume and mass than Saturn's largest moon, Titan, the second-largest moon.