Dwarf Planet

Pluto is today considered a dwarf planet. It is in a binary system with Charon. The mass of Pluto is smaller than our moon. Ploto is very far from the Sun and very cold. During the 20th Century astronomers and thegeneral public called Pluto a planet. Then it was discovered that there are many similar small bodies in the Solar System. Scientists held a convention in 2006 and decided that Pluto and several others would in future be called Dwarf Planets.

References and External links

 * Dwarf Planets: What Defines a Planet, Dwarf Planet or Plutoid?