Have you ever seen the Southern or Northern Lights? Earth isn't the only planet that puts on these beautiful light shows, which are also called the "aurora". Aurora have been seen at both poles of Saturn, too, as well as at the poles of Jupiter.
Ganymede A satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a orbital resonance with the moon