why is Pluto not a planet?

Question

i need to know it is geting on my nerves.!

Answer 1

Pluto Not a Planet, Astronomers Rule
Mason Inman
for National Geographic News
August 24, 2006 (Updated 3:30 p.m. ET)

Pluto has been voted off the island.

The distant, ice-covered world is no longer a true planet, according to a new definition of the term voted on by scientists today.

"Whoa! Pluto's dead," said astronomer Mike Brown, of the California Institute of Technology in Pasadena, as he watched a Webcast of the vote. "There are finally, officially, eight planets in the solar system."

In a move that's already generating controversy and will force textbooks to be rewritten, Pluto will now be dubbed a dwarf planet.

But it's no longer part of an exclusive club, since there are more than 40 of these dwarfs, including the large asteroid Ceres and 2003 UB313, nicknamed Xena—a distant object slightly larger than Pluto discovered by Brown last year.

"We know of 44" dwarf planets so far, Brown said. "We will find hundreds. It's a very huge category."

A clear majority of researchers voted for the new definition at a meeting of the International Astronomical Union (IAU) in Prague, in the Czech Republic. The IAU decides the official names of all celestial bodies.

The tough decision comes after a multiyear search for a scientific definition of the word "planet." The term never had an official meaning before.

Answer 2

1) Too Small
2) Wrong Orbit.

It's not large enough for gravity to make it into a round ball, for one, and I believe Kepler said there was a law about how the planets distance from the sun is governed. Pluto is too close to Uranus, and it's not even in the plane of the ecleptic. It was always questionable whether it qualified or not, but the finding of two REAL planets in the Oort cloud nailed it.

Answer 3

Like conquerer said: It's too small.

Astronomers decided to give a new name to small planets that don't do certain things that "real" planets do, for example clearing debris out of their orbit.

This new name is "dwarf planet". Pluto is classified as a dwarf planet now.

Answer 4

I look at it this way... Pluto seems to be little more than an undiferentiated rock, not dissimilar from our moon, whereas other bodies in our system have varying layers (surface, mantle, core, etc.) It looks more like a captured chunk of space debris, rather than something that formed from the same "stuff" as our own sun.

Or, maybe it's just too little.

Answer 5

Its not a planet because its merely a chunk of ice the size of my left testicle. It should have never been named a planet in the first place. In any event there is a "10th" planet out there that they havent actually named yet because they can't get a good look at it.

-J.

Answer 6

Best explanation I've heard is that if Pluto were the same distance from the sun as Earth it would be pulled into a non-spherical shape (tear drop I think).

Anyway, it comes down to size/mass/gravitational pull.

Answer 7

it is considered too small now to be a planet - the rules have been changed as to what size to be a planet - now pluto is an asteroid

Answer 8

bc they changed the definition of a planet and now Pluto doesnt fit there

Answer 9

Look up the answers to the last 500,000,000,000,000,000 times this question has been asked here.

Answer 10

It is a planet, stop listening to these scientists.