PSO J318.5-22 is a rogue planet (an extrasolar planet that does not orbit any star). It is approximately 80 light-years away from Earth, and belongs to the Beta Pictoris moving group. The estimated age of this planet is around 12 million years. Based on its calculated temperature and age, it is classified under the brown dwarf spectral type L7.
Dr Michael Liu, the team leader of the Institute for Astronomy at the University of Hawaii, stated: "We have never before seen an object free-floating in space that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone." Current theories about such objects include the possibility that gravitational perturbations may have kicked them out of their planetary cradles soon after they were formed through planetary accretion, or they may have formed in another way. Estimated temperatures inside its clouds exceed 1,100 K (800 °C). The clouds, made of hot dust and molten iron, show how widespread clouds are in planets and planet-like objects.