The largest moon of Jupiter is Ganymede. This moon is notable for being the largest moon in our solar system, even larger than the planet Mercury. Ganymede is primarily composed of water ice and rock, and it has a magnetic field, which is unusual for a moon. Its surface features a mix of two types of terrain: bright and dark regions, with grooves and ridges indicative of tectonic activity. Ganymede is a subject of interest for study, with potential implications for understanding the solar system's formation and possibly harboring subsurface oceans.