Pluto is also a dwarf planet. At first it was considered a planet, but later it was called a dwarf planet because it did not set one of the rules for being a planet. That is, it did not fulfill the condition of clearing its orbit, otherwise, if it did, it was now the planet. Pluto revolves very hard around the Sun, it's true it's very far, but ... He makes a complete rotation in 247.8 years. Pluto is also a bit strange, because its orbit is more oval and does not look like a circle, sometimes it even goes around the road it has to walk. Pluto was discovered in 1930. Pluto, as it has been established, also has satellites, his satellites being: Charon; Nix; Hydra; S / 2011 P1. Its atmosphere consists of nitrogen and carbon monoxide.