Clyde Tombaugh found Pluto in 1930. Pluto was named after the Roman god of hell. This name was suggested by Venetia Burney from England. She was eleven years old at the time.
Pluto has three moons: Charon, Nix, and Hydra. Charon is 1190 km across, half as wide as Pluto. Charon is about 19,410 km away from Pluto. Pluto and Charon spin around each other making the two look like a double dwarf planet. Nix and Hydra are much smaller, about 45-160 km across, about 44,000 km from Pluto.
There are eight planets in the Solar System. Pluto is very different from these eight planets. It is smaller than them and follows a different kind of path around the Sun. Pluto sometimes gets closer to the Sun than Neptune, because of the path it follows.
Mercury is the Solar System's smallest planet. Mercury is about twice as wide as Pluto. Mercury has about twenty-five times the mass Pluto.
We used to call Pluto the ninth planet. However, in August, 2006 the International Astronomical Union said that Pluto should not be called a planet anymore. They said that it should be called a dwarf planet instead; and it now is called a dwarf planet.
|The Solar System|
|Star: The Sun|
|Planets: Mercury • Venus • Earth • Mars • Jupiter • Saturn • Uranus • Neptune|
|Dwarf planets: Ceres • Pluto • Eris|
|Small solar system body: Asteroid belt • Comets • Meteors • Kuiper belt • Scattered disc • Oort cloud|