Triton (also known as Neptune I) is the largest satellite of the planet Neptune in the Sol System. It is the seventh-largest moon in the system, somewhat larger and more massive than the dwarf planets Pluto and Eris at 2707 km diameter and 0.0035% the mass of Earth. It is a major human colony, although by the standards of Sol it is a minor one with a population of about 200 million (99980 census). It is the largest unterraformed moon in the system. It is also holds one of the largest populations for an unterraformed body within human space.
Scientists are now certain that Triton used to be a Kuiper Belt object which was captured by Neptune's gravity a long time ago. It was first observed by astronomer William Lassell in 1846. The first human exploration of the object was the famous probe Voyager 2 in 1989, when the scientists involved in the mission decided to sacrifice the chance of exploring Pluto to study Triton instead. The first human explorers to step on Triton landed on 2059 (coincidentally, 70 years after the first flyby), just before the first Warp Drive was created.
Although receiving relatively little attention from the colonists who mainly went for the Jovian and Saturnian system, Triton (and Neptune) had their own colonists arrive on 2061, just two years after the first human landing. The low solar intensity around Neptune and a lack of valuable minerals, however, made such endeavors less profitable compared to those coming to Mars or Europa, for instance. Due to this, the population on Triton remained below 25,000 until well past the year 3000.
As the Earth got strict regulations to reclaim the environment and Luna, Venus and Mars got overpopulated, many corporations and residents wishing to live and work in Sol turned to other bodies, including Triton, to find unoccupied land. Triton's decent gravity and size made up for its distance from the sun, and soon enough the population exploded. On 4000, the population of Triton crossed the 1,000,000 mark. By this time, proposals were sent to terraform the icy moon.
A team of scientists surveyed the system further and determined a terraforming would be disastrous for the planet (the crust of the planet consisted of volatiles), and will take a massive amount of time and resources. Hence humans had to continue living in biodomes and habitats dotted throughout the moon. After the initial expansion the population growth slowed and the population only reached 10 million by 9250.
Triton is the headquarters of a multitude of intersystem companies which are not large enough to open their main office in the core planets, forming the base of the local economy. The lack of a substantial atmosphere with noticeable gravity also made it a local tourist attraction to experience 'a genuine moon' (colonists from outside the system deal with this routinely).
A mining industry exists which extracts ices and exotic compounds from the planet. Most of Triton's population work somewhere else in the system, though, and commutes with an interplanetary shuttle service. Triton's biodome agriculture produces a slight surplus which are mainly exported to Luna.
Many cupoles have been built on the frozen moon to recreate an Earth-like atmosphere. There are some projects about pre-terraforming the moon (e.g. create an Earth-like day and add CH4 and CO2 to the atmosphere).
Triton's position as a solar system body dictated a need for protective military. Triton holds its separate armed forces district within the Sol Military HQ, the Tritonian Division. Its juridiction includes all the moons of Neptune (but not Neptune itself). It is manned by about 300,000 men, the size of two regular armies, with plenty of them veteran of the Second Galactic War.
Despite so, no attacks have ever been attempted by terrorists or foreign entities on Triton, perhaps due to its lack of a strategic/morale target.