Pluto: The Dwarf Planet

Pluto

• astronomers discovered that it appeared much larger than it is because of the brightness of its satellite, Charon, which is almost half the size of Pluto

• was considered as the ninth planet in the solar system

• at first, it was thought to be the size of Earth

• was not able to clear its orbit of other objects due to lack of gravity

• is a prototype for the new classification for celestial bodies called dwarf planets

Eris

• a Kuiper Belt object, was discovered and was estimated to be 10 percent bigger than Pluto

• was discovered in 2005

Haumea

• was discovered earlier in 2003

Other dwarf planets: Ceres in the Asteroid Belt, and Makemake and Haumea in the Kuiper Belt