Athenaeum World X

Athenaeum World X is one of the Cabal Empire's Athenaeum Worlds, vast planetary repositories of knowledge and technology. This particular Athenaeum World was a hostile, ice planet home to a species of dangerous wildlife capable of suppressing the Light of Guardians and other Light-bearers. It is suspected to be the same world visited by the Drifter during his expedition out of the Sol System.

Among other items and knowledge, Athenaeum World X supposedly contains information regarding the Aphelion.