Pluto

Pluto (provisionally Sol j) is a large dwarf planet located in our local Solar system that was considered a planet and still is if Dwarf planets are counted as planets. Pluto is an ice planet, and may have potential for Entities if it has enough heating for a subsurface ocean. But, none have been detected. Pluto has 4 or 5 moons, depending on whether Charon is counted as a double planet or a moon. It has a seasonal atmosphere.

Classification
Pluto was discovered in 1930. It was originally classified as a planet that had the size of Earth. But the estimate of Pluto 's size kept on going down, and in the 70s through aughts people were finding other objects like it left and right, such as Charon and Eris. In 2005, the IAU created the Dwarf planet category that was arbitrarily designed to exclude these objects and classified Pluto as a Dwarf planet candidate. This definition was controversial, and many people thought that Dwarf planets should be classified as a type of planet, that Pluto should be migrated back or that they should be removed entirely.