The Diomedes System was one of the colonies colonised by the Empire in the early 4th Millenium, and was among many ravaged by the First Colony War. The systems' star is Ra.
- Bacchius - A large farm world in the system.
- Artemis - One of the two largest farm worlds in the system, presumably sending exports to Earth.
- Iris - Home to the natural wonder of the system, the rings of Iris.