Pluto

Pluto is a diminutive planetoid in the Sol system.

Overview
There are no facilities on the dwarf-planet's surface; however, several military and scientific stations orbit Pluto, including the Kelvin Research Station, UNSC Monitoring Station Delta Five, and the remote scanning outpost, Democritus.

History
Pluto was discovered in the early 20th-century. It was originally considered a planet and thought to be causing issues in Neptune's orbit but was then downgraded to a dwarf planet when Pluto was determined to be ill-suited for that.

Human-Covenant war
On November 3, 2552, Democritus detected Cortana's signal in slipspace with Dr. Halsey's message to Fleet Admiral Terrence Hood.

Created conflict
In October of 2558, Pluto and its orbital installations came under the control of the Created, along with the rest of the UEG's colonies in the Sol system.

List of appearances

 * Halo: Ghosts of Onyx
 * ''Halo Evolutions
 * The Impossible Life and the Possible Death of Preston J. Cole
 * Halo: Hunters in the Dark
 * Halo 5: Guardians
 * Halo Mythos