PSO J318.5-22, discovered in 2013 by Pan-STARRS, is a rogue gas giant ~6 times Jupiter’s mass floating alone in space—no orbit around any star. Formed like a planet but ejected from its system, it glows from leftover heat (1,200°F/650°C surface).
No habitable zone without a star, but its auroras might light up like Jupiter’s.
This lonely world reminds us planets can wander the galaxy like cosmic nomads.