Dead World

From Conworld

A δ-class (delta class) or Dead World is an airless and completely sterile world, totally devoid of an atmosphere and native natural life, and unsuitable for supporting any. With the possible exception of Terran facilities such as Research Stations, based on the planet, its population is otherwise nonexistent.

Some planets have always been dead worlds; others were originally living worlds, reduced to dead world status through apocalyptic events, such as exterminatus, Tyranid consumption and destructive internecine war.