Jupiter is the fifth planet from the Sun and the largest planet in the Solar System. For understandable reasons, Jupiter itself was uninhabitable, but some of its moons did serve as temporary military bases and battlefields.
Jupiter was first seen in the episode "Goku's Ancestors" as Vegeta and Nappa flew past it on their way to Earth. It was next seen in "Plans for Departure" when Mr. Popo flies Kami's ship to Jupiter in a matter of seconds, showing Bulma, Rad, Carlos and Alexis how fast the ship is.
Jupiter is a "gas-giant" and most notable for its "Great Red Spot", as it is one of the Outer Planets of the Solar System. The Red Spot is referred to by Raiti when the group come upon the tornado on Fake Namek. He states that the storm never dies, like Jupiter's Red Spot. Also, the Red Spot is referred to by XANA when he possessed Gozaburo Kaiba. He states that the flames never die, like Jupiter's Red Spot.
The planet may have four rings, but it is presumably hidden or not shown at all in the anime.
Io, the innermost of Jupiter's Galilean moons, served as temporary base for Admiral Winfield's Exofleet remnant in the first years of the war. The moon has seen several fierce battles but in the end, General Typhonus forced Exofleet to retreat further away from the Homeworlds. However, by then, Winfield has already allied himself with Jonas Simbacca, who provided him with a new base - Chaos.
Sinope was one of the farthest moons of Jupiter. "Sinope Base" was the location of Phaeton's top-secret super-weapon, Fusion Pulse Cannon, designed to wipe out both the Pirate Fleet and Exofleet's base on Io. However, the Cannon only managed to fire roughly a dozen bursts at the Pirate Fleet before a combined Exotrooper-Pirate task force damaged the core of the weapon's "energy silo," causing an explosion which completely destroyed the cannon and obliterated Sinope. Its debris caused a "meteor swarm" that heavily damaged the Neosapien fleet under the command of General Typhonus, who was on his way to directly attack the Pirates and Io Base. The Neosapiens were forced to retreat, which gave the Terrans enough time to evacuate. Sinope was restored by Porunga.