The Arcturuans come from the planet Arcturus IV, which due to its two suns is in perpetual light. It is believed this caused the people to go mad and once they invented atomic weapons they nearly destroyed themselves. Following the war, only two factions remained - the Reavers and the Mutants. The mutants were peaceful but disfigured, something the Reavers would hate and hunt them for.
The planet Arcturus IV was said to be destroyed by the Planet Pulverizer weapon of Lord Votan before it arrived on Earth and was stopped by the Star Masters.