Jupiter Moons

Jupiter AR

Jupiter's four largest moons, Io, Europa, Ganymede and Callisto, were discovered in 1610 by Italian astronomer Galileo Galilei. It took another 369 years for scientists to confirm that Jupiter--like its neighbor Saturn--has a ring system as well. The NASA Voyager 1 and 2 missions observed three faint rings in 1979. Ganymede is the largest moon in the solar system and is even bigger than the planet Mercury.

Images of Jupiter