The Galilean moons are 4 massive satellites of the planet Jupiter. They had been found by Galileo Galilei within the early 17th century, therefore their identify. The 4 moons are Io, Europa, Ganymede, and Callisto. They’re among the many largest objects within the photo voltaic system outdoors the solar and the eight planets, with Ganymede being the most important moon within the photo voltaic system, even larger than the planet Mercury. These moons are very numerous, every providing distinctive geologies and potential for all times. As an illustration, Io is volcanically energetic, whereas Europa and Ganymede are believed to harbor subsurface oceans. The Galilean moons have been the main target of quite a few area exploration missions attributable to their intriguing options and potential habitability.