Pluto (dwarf planet)
For other uses of the name, see Pluto (disambiguation).
From its discovery in 1930 until 2006, Pluto was considered equal to the eight other planets of the solar system - the furthest one from the sun, taking 248 Earth years to complete one orbit. Like most other worlds in the region, it hosts moons - Charon was identified in 1978, with Nix and Hydra discovered in 2005. However, astronomers came to realise that Pluto was actually the largest body of a much bigger collection at the fringes of the solar system - rocky, icy objects remaining from its formation, that together make up the Kuiper belt. Therefore, in 2006 Pluto's status was reassigned by the International Astronomical Union to 'dwarf planet' - something with enough mass to become spherical, but which has not through its own gravity 'cleared the neighbourhood' of other objects around it.