In Star Wars, one such planet is Mustafar, with its heat caused by tidal forces from nearby gas giants.
Animal Planet | minor planet | Mercury (planet) | Lonely Planet | Planet of the Apes | planet | Forbidden Planet | Planet Rock | Planet of the Daleks | Planet of the Apes (2001 film) | Planet of the Apes (1968 film) | Planet | Fantastic Planet | Animal Planet Nordic | Treasure Planet | Planet of Evil | Planet in Peril | Planet Earth (TV series) | Planet Earth | Lost Planet of the Gods | Planet Rock (song) | Planet of Fire | Minor Planet Center | Minor planet | Earth-like planet | Commander Cody and His Lost Planet Airmen | Beneath the Planet of the Apes | The Planet Smashers | The Blue Planet | Saving Planet Earth |