They are here! The Moons of Jupiter join the cast! Meet Ganymede, Europa, Callisto and Io as they... do stuff.br br Fun Facts:br Iapetus gains a voice in this episode.br This episode was the first to mention exoplanets.br This is also the episode in which Triton is first mentioned.br This episode is the first time we see Jupiter and Saturn arguing.br Ganymede and Europa meet Titan in the Asteroid Belt.