Runaway Planets: The Rogues of the Universe A rogue planet (or a free floating planet) is generally a Jupiter sized body that inhabits the space between stars, unbound by the gravity of a parent star. It's believed that these planets either formed directly from the collapse of interstellar gas clouds (like stars) without having the mass to ignite (like a brown dwarf), or they were formed in a planetary system and they somehow overcame the gravity of their star and were eje
Rogue planets can form without a parent star. Scientists call them free-floating planets — massive celestial wanderers that have broken free from the confines of their original solar system. Or perhaps not. New research suggests that these so-called rogue planets may have formed completely on their own — and that there could be billions of them.