http://msnbc.msn.com/id/14789691/

Pluto got PWNED (j/k)

I think it's the right thing to do, you have to accept change.

but doesn't pluto orbit the sun and is a big body of mass. doesn't that make it a planet? first it was 12 planets, then back to 9 now its 8. they need to make up thier ****ing minds lol(i think it should just be 9)

I think 8 is going to be the number.

I think the major thing that led to this decision is the finding of a dwarf planet (aka Xena) larger than pluto but with a much more excentric orbit.

So I imagine a good definition of the a 'prime' planet would be a large body that has a nearly circular orbit on the same plane as other planetary bodies that have similar orbits. Pluto doesn't fall into this category.

Also another reason why it got canned is that Pluto and it's moon rotate around each other.

no they don't. the moon only orbits around pluto. and the planets orbits are slightly eliptical. someone said though that neptunes gravity actually sorta helps pull pluto along a little bit so maybe thats why.

Pluto's orbit is not on the same plane as all the other planets, and it doesn't have a circular orbit.


Also Pluto's moon is rather large in relation to the planet, so their sort of orbit around each-other.

http://upload.wikimedia.org/wikipedia/en/0/0d/Pluto_system.jpg

Pluto has a Barycenter, think of it as a 'center of gravity'. Charon and pluto are always at opposite ends of each other's orbit, rotating around the Barycenter. The reason for this is that Charon is large and close enough to have a gravatational pull on Pluto that slightly offsets it from a normal Planet/Sattelite relationship seen in other planet systems.

Dwarf planet Pluto isn't alone though, welcome in Eris and Ceres!

There may be several other additions later on as astronomers confirm the size/orbits/etc of several other large Kuiper-belt objects.

http://news.bbc.co.uk/1/hi/sci/tech/5344892.stm

At least now i can tell my children when i get older that was alive when pluto was a planet

the real reason it got canned was the name: pluto. wtf it's a dogs name for christs sake.