Why is Pluto not a Planet?

Pluto was discovered in 1930 by Clyde W. Tombaugh.  Pluto was meant to be the ninth planet of our Solar System.  In 2006 it was decided Pluto was to be a dwarf planet because of its size and it had no gravity.

Pluto orbits the sun but it goes around the sun in an oval.  The other planets orbit the sun in a circle.  The closet Pluto gets to the sun is 4 440 000 000 kilometres away.  The furtherest it gets is 7 380 000 000 kilometres.

Pluto is so far from the sun it is colder than the North Pole there.  It is as cold as -210ºC.

Pluto has five moons, called Charon, Nix, Hydra, P4, and P5. Pluto is made of rock which is covered in ice.  There is no oxygen on Pluto so we would die there. 

Bibliography

http://en.wikipedia.org/wiki/Pluto

http://www.space.com/43-pluto-the-ninth-planet-that-was-a-dwarf.html

By Sapa, Tristan and Jean-Eve