Jupiter is the fifth and largest planet in the Sol System. As of 200000 CE, it and it's 79 moons are home to over 50.6 trillion inhabitants (the vast majority of which are Human). The four largest of the planet's numerous moons are named Io, Europa, Ganymede, and Callisto,
Most of the inhabitants of the planet reside in orbital habitats rather than on any natural body, and most of those that reside on natural bodies live on the moons. Even so, there are several billion individuals which live on floating cities on the planet. Each city is surrounded by large domes to create a stable atmosphere. Rather than using expensive anti-gravity technology, these cities use heated gas chambers similar to hot-air balloons, to stay afloat (as most of them were created before anti-gravity technology even existed).
The largest and oldest city, Galilei, has a population of over 13.5 million. Most other cities are far smaller communities built around deuterium and ammonia processing plants.
An artificial set of rings were constructed around the body at around the same time Earth received her own ring system. This ring system is mostly composed of communications satellites, orbital habitats, and other structures. There is little left of Jupiter's natural ring, mostly because the risk that free particles pose to ships.
Jupiter formed initially as a rocky body which then attracted many different gasses around four billion years ago. It eventually became the largest planet in the Sol System, attracting seventy nine moons including the Galilean satellites. Jupiter formed a very thin ring system as well.
The first city to be established in the planet's atmosphere was Zeus, a dirigible city modeled after those used on Venus. It was placed in low atmospheric orbit in 2200.
Near the turn of the tenth millennium, a proposal to turn Jupiter into a brown dwarf was put forward but was widely rejected due to concerns that the project could go awry and destroy the entire system.
Jupiter's global population is currently 50.6 trillion, all of whom live on massive floating cities and artificial floating continents that move through the clouds at a speed which emulate terrestrial day/night cycles.