Class R

Rogue planets, do not orbit stars. Instead, they float in the cold darkness of space. They most likely normally formed within a solar system but have been flung deep into space usually caused by the collision with another planetary body. The surface of a rogue planet would usually be barren, but some might be temperate due to geothermal venting with atmospheres filled with volcanic gases. Life would be rare, but some may have unusual life that gather near volcanic regions. The surface life would exist in complete darkness with plant life that is non-photosynthetic in nature.