The best of the Jupiter system is pictured in this collage of images acquired by the Voyager and Galileo spacecraft. Jupiter is the largest planet in our solar system. The four largest moons of Jupiter are known as the Galilean moons and are named Callisto, Ganymede, Europa, and Io. Inside the orbits of the Galilean moons are Thebe, Amalthea, Adrastea, and Metis.
At the lower right is shown the Valhalla region of Callisto. Ganymede is toward the bottom middle. Europa is a little above and to the right of Ganymede. Io is the top, left-most moon. Between Io and Jupiter are four little moons. The top-most little moon is Amalthea. Below and to the right of Amalthea are Metis and Adrastea. To the left of Adrastea is Thebe.