Pyro IV

Pyro IV is a rocky "Mercury-like" protoplanet in the Pyro system. Although classified as a protoplanet in the Starmap, Pyro IV is actually the outermost natural satellite of the gas giant Pyro V. Astronomers believe that Pyro IV was once the fourth planet from the sun in the Pyro system. However, a collision with a large celestial body knocked Pyro IV out of its orbit and into its current position around Pyro V. The impact destroyed Pyro IV's atmosphere and significantly altered its landscape. While Pyro IV has developed a new atmosphere, it is not habitable and remains on a collision course with Pyro V. Eventually, Pyro IV will either crash into Pyro V or be torn apart and become a ring system.