If Pluto isn't a planet, what is it?

Question

I know, dumb question..

But what is it? And why isn't it a planet?

Answer 1

a big **** rock

Answer 2

its now called a dwarf planet... it it were to be considered as a planet then many others like sedna would have to be considered as planets... the fact that pluto is very small makes it a dwarf planet and and also of its radius of rotation is very large so its not a planet.

hope that answered your question

Answer 3

It used to be called a "dwarf planet", but recently the IAU changed the nomenclature. It is now called a "plutoid" along with all other formerly-dwarf-planets.

Answer 4

It's a Dwarf Planet.

It's also a minor planet.

It's also a Trans Neptunian Object (TNO).

And it's not a planet because the IAU decided it isn't.  They disguised this decision with an absurd definition.

Answer 5

It's now being classified as a dwarf planet.

From Wikipedia

The IAU therefore resolves that planets and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way:

(1) A "planet"1 is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit. (THIS QUALIFICATION IS THE ONE PLUTO FAILS TO MEET)

(2) A "dwarf planet" is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects3 except satellites orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".

Answer 6

Its not a dumb question at all! It has been down graded in classification to what astronomers call a dwarf planet.

It just didn't meet all the necessary requirements for a planet. There are asteroids larger than pluto.

Heres a site for more info:http://www.astro.cornell.edu/~jlm/planet...

Answer 7

It is a Dwarf planet.... it was to tiny...i liked Pluto too.... :(

Answer 8

They call it a planetisimal. It was downgraded because of its small size.

Answer 9

It isn't a planet anymore because they decided to change the definition of a planet and Pluto didn't fall as a planet under the new definition. As said above it is now a dwarf planet.

Answer 10

It really isn't a dumb question, it is actually a very good question and there is a lot of controversy about it.

Pluto has changed classifications 3 times since it was first discovered in 1930. It was originally considered a planet until 2006 when it was demoted to a dwarf planet by the IAU (International Astronomy Union). But there was a lot of controversy over WHAT  dwarf planet is. It is just a planet in an asteroid belt, no matter what the size? Is there a certain mass that it needs to have in order for it to be considered a planet instead of a dwarf planet? Well, its hard to answer these questions based on the knowledge we have obtained from our solar system because it is the only one we can observe in detail. The closest extra-stellar solar system is over 4 light years away and we can barely see the planets, much less celestial bodies in asteroid belts. So until we do study other solar systems in detail, we can't make a lot of  statements about what IS a planet and what ISN'T a planet.

So the IAU made a special classification just recently that classifies these celestial bodies in our own solar system. We call them "Pluto's". So now Pluto and other celestial bodies like it found in the Jupiter Belt are considered "Pluto's" which are celestial bodies laying beyond Neptune in the Jupiter Belt that meet all the criteria of a planet, but lie in an asteroid belt. So now Pluto is officially a "Pluto" which is basically a sub classification of a "dwarf planet" which is a sub classification of a planet. Make sense? I know it sounds confusing and thats why there is a lot of controversy behind it. I'm suprised to see the amount of people that didn't give real answers. Sorry, I know its frustrating.

As for why Pluto isn't a planet, it is because there are probably hundreds of bodies similar to it lying the Kupiter Belt, and we don't need an additional hundred planets in the solar system or kids will have a hard time remembering it for science class!