why was the planet Pluto kicked out of the solar system?

Answer 1

http://en.wikipedia.org/wiki/Pluto
http://www.iau.org/fileadmin/content/pdfs/Resolution_GA26-5-6.pdf

on 24 august 2006, the international astronomical union reclassified pluto.

this was the right thing to do, believe me. this does not change anything about pluto or the solar system. this just corrects the mistake of classifying pluto as a planet initially.

pluto does orbit the sun, is ball-shaped and is not a satellite, but it does not have an isolated orbit (a bunch of other similar bodies have similar orbits.) so it is not a planet.

i have been waiting for this since i was about ten when i learned that pluto didn't fit the pattern set by the major bodies in the solar system so it was an anomaly. it just felt "out of place". now that astronomers have found hundreds of other bodies with similar orbits, classifying "134340 pluto" as a planet is even more irrational. i feel somewhat satisfied, but i don't know how long this will drag on tho. many planetary astronomers are satisfied that the definition is rigorous enuf. i can accept that the definition is flawed, but i can not accept that "134340 pluto" is a planet.

this same thing happened has happened before. in 1800, an astronomer found a body orbiting the sun between the orbits of mars and jupiter and thought it was a planet. astronomers finally stopped classifying them as planets after they found several other bodies with similar orbits, and no one thinks ceres, pallas, juno, and vesta are planets today.

many astronomers consider pluto and charon to be a binary system, but two small bodies orbit that system. they are called nix and hydra.

incidentally, "134340 pluto" was never a moon of neptune. neptune did capture triton. this is why triton has a retrograde orbit.

Answer 2

The International Astronomical Union decided that Pluto was no longer a planet. The reason is that while Pluto is round, orbits the sun, and has three moons, it has not cleared (via gravity) its own orbit of debris. Instead, they decided to classify it as a "dwarf planet".

See the details below.

RESOLUTION 5A
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" [footnote 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.

(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) shape [footnote 2] , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects [footnote 3] except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".


Footnote 1: The eight "planets" are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Footnote 2: An IAU process will be established to assign borderline objects into either dwarf planet and other categories.

Footnote 3: These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

RESOLUTION 6A
The IAU further resolves:

Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.

Answer 3

It has an elliptical orbit that sweeps inside a planet's orbit and is out of the plane of the eight recognized planets' orbits. This is more characteristic of a comet, so Pluto is more likely to be a captured object like a comet rather than formed from the same disk of material that the other planets were. It isn't the first "planet" to be kicked off the list, either. There was a tiny one discovered in a band later recognized as an asteroid belt. So it was discovered, named, recognized as a large asteroid and demoted.

Answer 4

By the way, it was not kicked out. The scientist voted it out of the "planet category". They said it didn't hvae the feauters that some of the scientist's "planets definitons" say. It was too small, too far, too something, too something.
Some scientist did want Pluto in so they voted but the other one won, but because the votes were so close to each other they named it "Dwarf Planet". There are aslo some more planets in that category.

Answer 5

Flunked the inspection! It was too small. I feel so sorry for pluto. After all this time of think he was a planet he gets demoted. I would have thought they could grandfather him in and just promise not to name any of his pups a planet after him.

Answer 6

it was kicked out because it was to small and it sometimes orbited into neptunes path so it technically didnt have its own orbit so now they put into a group called a dwarf planet.

Answer 7

the people (scientists) are always crazy to do new things...so highlight themselves, they kicked off PLUTO since they could not find a newer planet...they decided to kick off pluto....poor pluto....

Or may be...the wives of the team of scientists had a bad relation with some other scientist named PLUTO...so they decided to kick it off....

Answer 8

Because the planet is considered to small to be a planet. I think we should have kept it because i'm really confused now.

Answer 9

This is because its charesteristics opposed those of a real planet's!ü
That's what our teacher told us..

Answer 10

because it didn't meet the characteristics of a planet....