Jupiter

Image of Jupiter, no moons visible

> "*The Solar System consists of Jupiter, plus debris*"
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> —Isaac Asimov

**Jupiter** is the fifth planet from Sol and the largest planet in the Sol system. Although it lacks any population itself due to the planet being a gas giant, its moons are home to thirty-seven million inhabitants. Jupiter is the third brightest natural object in the Earth's night sky after Luna and Venus, and has been observed since prehistoric times. It was named after Jupiter, the chief deity of the Roman religion.

Jupiter is primarily composed of hydrogen (90% by volume), followed by helium, and rotates rapidly, once every 10 hours. The outer atmosphere is divided into a series of iconic latitudinal bands, with turbulence and storms along their interacting boundaries. The most obvious result of this is the Great Red Spot, a giant storm which has been observed since 1831 and possibly earlier, although it is currently in decline, expected to dissipate before 2200.

Jupiter has had a brief, but tumultuous history in modern times - its moons were first explored in the late 2070s, and settlement began shortly afterwards as intense competition for extra-planetary territory drove settlers to the moons in droves. The prospect of helium-3 mining within Jupiter's atmosphere was also an inciting prospect, as it would cut Earth's dependency on Lunar energy. However, as competition to settle the Jovian moons continued, skirmishes began between competing nations broke out, eventually devolving into full-blown local wars. The first of these wars was fought on Ganymede between China and India, which resulted in the moon gaining independence. The Second Jovian War led to Europa and Callisto gaining independence, after an insurgency fought against the UEF and US which had colonized the two moons. The Third Jovian War was a full-fledged conflict pitting the US and UEF against Luna, Mars and the independent Jovian Republics, which later federated into the Jovian League.

Today, Jupiter's gravity well is considered to be the territory of the Jovian League, who charge considerable tariffs for using the planets gravity well for slingshot maneuvers to the outer planets.

## Major Satellites

* Io - the innermost and third-largest of the four Galilean moons of the planet Jupiter. Slightly larger than Earth’s moon, Io is the fourth-largest moon in the Solar System, has the highest density of any moon, and the strongest surface gravity of any moon. Contains a small scientific population of ~1000

* Europa - the smallest of its four Galilean moons, but still the sixth-largest moon in the Solar System. It is primarily made of silicate rock with a water-ice crust, and an iron–nickel core. Contains a metropolitan population of 16 million

* Ganymede - the largest of Jupiter's moons, and the largest moon in the solar system. Ganymede is composed of approximately equal amounts of silicate rock and water, with a liquid iron core and subsurface ocean. Contains a population of 14 million, and has the capital of the Jovian League, Unity Station in orbit around the moon.

* Callisto - the second largest Jovian moon, and is tidally locked with Jupiter. Callisto is about half ice with a metal and rock core. Contains a population of 7.8 million