Pluto

Pluto is a small celestial object in the Solar System, and the second-largest known dwarf planet (after Eris) as well as the tenth-largest body observed directly orbiting the Sun. It was named after the Roman God of the Underworld. The Remote Scanning Outpost Democritus is on this Dwarf Planet. On November 3, 2552, the Monitoring Station detected Cortana's signal in Slipspace with Dr. Halsey's message to Lord Hood. As of 2552 there are no human facilities on the dwarf-planet's surface, however several military and scientific stations orbit Pluto.

History
Pluto was discovered in 1930, then thought to be the ninth and final planet of the Solar System. Its first moon, Charon, was discovered in 1978. In 2005, two more smaller moons were discovered. In 2006, arguments began to arise on whether Pluto was actually large enough to be considered a planet. After much debate, Pluto (along with the asteroid Ceres and the object Eris) became newly classified as dwarf planets.

In 2007, a space probe named New Horizons was launched to gather more information on Pluto. It was scheduled to arrive at the dwarf planet in 2014 or 2015. It will be the first spacecraft to ever visit Pluto.