Lucifer was a gas giant that orbited a red giant near the end of its life, 280 light-years away from Earth. It had four moons: Astarte, Belial, Moloch, and Demogorgon. Its atmosphere gave off a glow called "the Ring of Lucifer". Its surface was a combination of cloud and zelanite.
In 2152, Project Eden was established on the moons to study the technology. In 2157, IMC came to claim the mining rights for Lucifer and set up controlled black holes around it to strip away its atmosphere. In defence, the Angels set up an impenetrable exclusion zone around the system lasting until at least the 26th century. (PROSE: Lucifer Rising)