Why is Pluto not a planet anymore?

Question

I miss it.

Answer 1

Well, dont "miss it", because it has not gone anywhere...Its still out there in the cosmos:)

Basically, its got an erratical orbit and sometimes its out side the orbit of Uranus, and some times its inside the orbit of Uranus, so, its just a wayward astoroid that is a bit smaller than our moon, that happened to get the attention of an astronomer and he classified it as a planet.

But, its not really a planet, because it doesnt have enough "mass" to make it one. Asteriods can orbit amongst themselves, and we dont call them "planets". They have to have a certain amount of mass, to ensure they are a proper planet.

Lets face it, Pluto can be knocked out of orbit if a huge asteroid collides with it!! The Earth cant. (Though, we would face catastropic consequesnces and the people would probably dissapear from the face of the Earth if a large enough asteriod hits us).

So, I wouldnt worry about Pluto, its still hanging around in its erratic orbit, and who knows, some day it may be around here, if it gets knocked out of orbit :)

I wish you well..

Jesse

Answer 2

Because it's not in the same elliptical plane as the
other 8 planets are. This has been a problem for some time now but came to a head when several more of
these types of solar orbiting bodies were recently
discovered. They are in an orbital area around the sun
called the Kuiper belt. So the world astronomical community had to redefine "planet" to exclude Pluto and the rest of them or leave the definition and accept a growing number of planets. They opted for the former . But of course, it's not like we just realized that
Pluto is not a planet. The word "planet" is arbitrary.
We can define it the way we want. Then we must include
and/or exclude objects accordingly and consistently.

Answer 3

the international astronomical union defined three terms "planet", "dwarf planet", and "small solar system body". this does not change anything about the solar system or pluto. it just corrects the mistake of classifying pluto as a planet initially.

i have known since i was about twelve that pluto does not have the physical and orbital characteristics that fit the pattern set by the major bodies in the solar system, and later, after the discovery of hundreds of other similar bodies with similar orbits, i knew this was inevitable. this was the right thing to do, believe me.

because pluto orbits the sun, is round, orbits the sun with a bunch of other similar bodies with similar orbits, and is not a satellite it is a dwarf planet.

(1) A 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, and (c) has cleared the neighborhood 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, (c) has not cleared the neighborhood around its orbit, and (d) is not a satellite.

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


look here:
http://www.iau2006.org/mirror/www.iau.org/iau0603/index.html

Answer 4

Same reason as in the answers people have been giving to this question all week. The certifying group changed the rules so bitty-sized things don't count as planets. Pluto was bitty sized and now it can't be called a regular planet.

Answer 5

The 2006 redefinition of planet by the International Astronomical Union (IAU) states that, in the solar system, a planet is a celestial body that:

* is in orbit around the Sun,
* has sufficient mass so that it assumes a hydrostatic equilibrium (nearly round) shape, and
* has "cleared the neighborhood" around its orbit.

Pluto does not satisfy the last point. Thus, it has been classified as a "dwarf planet"

Answer 6

pluto is a planet which compostion are just assumed by the scientist, helix Mc Bolie has reccomended it as planet after discovering its exist
but presently its composition its still in contrary hence there is a huge contradicition in its exist

Answer 7

Does not follow an independant orbit and it is smaller than another orbiting mass out there that will be the new 9th planet.

Answer 8

Because some really smart people in Prague said so.

Answer 9

because we can likely to find more PLUTO

Answer 10

cause the government said it is no longer a planet. and they think if they can convince you of this then they can convince you of anything. so are you convinced