Why is Pluto no longer a Planet?

Answer 1

Oh, there are lots of reasons for this.

One of the biggest reasons for this is its size. Pluto is only slightly bigger than a few asteroids in the solar system, smaller than at least one of the larger planet's moons, and only slightly bigger than its own moon. Many astronomers figured that if Pluto was a planet, the others would have to be, which would've brought the total up to 12.

Some of the other reasons are its orbit, which is elliptical and not circular like the other planets, and its distance from the sun which puts it in Kuiper Belt.

Pluto's downgrade from planet to dwarf-planet is just a result of the new parameters on what makes a planet. It's like the small, skinny boy trying out for the football team, it just didn't make the cut.

Answer 2

http://en.wikipedia.org/wiki/Pluto

pluto does orbit the sun, is ball-shaped, does not have an isolated orbit (a bunch of other similar bodies have similar orbits.), and is not a satellite so it is not a planet. this does not change anything about the solar system or pluto. it just corrects the mistake of classifying pluto as a planet initially. i don't know how long this will drag on tho. many planetary astronomers are not satisfied that the definition is rigorous enuf. i can accept that the definition is flawed, but i can not accept that pluto is a planet.

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

i have been waiting for this since i was about twelve. i feel somewhat satisfied. i knew 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. this was the right thing to do, believe me.

incidental, "134340 pluto" was never a moon of neptune. neptune did capture triton. this is why triton has a retrograde orbit.also, "13199 eris" is about five percent bigger than "134340 pluto".

Answer 3

Pluto, the last planet to join the heavenly pantheon, became the first to leave it. The status of Pluto had been under discussion for some time, but with the discovery of 2003 UB313, nicknamed Xena, the question became acute, for it seemingly had as much right as Pluto to be called a planet.

On August 24, 2006, the International Astronomical Union surprised the world by voting in a new definition of planet, one that would exclude Pluto and bring the total number down to eight. (There had previously been been strong speculation that the redefinition would bring the total up to 12 instead of down.)

Pluto was instead classified as a dwarf planet, along with Ceres and the aforementioned Xena. The main difference between a dwarf planet and the real thing is that the dwarf variety has not cleared the area of its orbital path.

This redefinition met with a wave of protests from those who wanted to see the ninth planet grandfathered in, including but not limited to supporters of the late Clyde Tombaugh, who discovered Pluto in 1930. His widow, however, said he would have been accepting of the IAU's decision since "he was a scientist" and understood that astronomers had to take into account newly discovered objects in the Kuiper Belt (where Pluto is located).

Answer 4

Pluto's orbit is very unusual in comparison to the planets of the solar system. The planets orbit the Sun close to an imaginary flat plane called the plane of the ecliptic, and have nearly circular orbits. In contrast, Pluto's orbit is highly inclined above the ecliptic (up to 17° above it) and very eccentric (non-circular). Owing to the orbit’s inclination, Pluto's perihelion is well above (~8.0 AU) the ecliptic. The high eccentricity means that part of Pluto's orbit is closer to the Sun than Neptune's.

Pluto's official status as a planet has been a constant subject of controversy, fueled by the past lack of a clear definition of planet, since at least as early as 1992, when the first Kuiper Belt Object, (15760) 1992 QB1, was discovered. Since then, further discoveries intensified the debate in the 21st century.

Answer 5

Because the Astronauts says that pluto is a Dwarf Planet.

Answer 6

Pluto's weird compared with other planets. It has a tilted and bizarre orbit (at sweeping inside Neptune's orbit), it's the smallest, and it's moon Charon is very big for its size.

There was talk of whether it counted as a planet even before the "10th planet" Eris was found (farther away than Pluto but slightly bigger).

Answer 7

I heard that on the news! Friends and I think it seems unkosher after learning basic astronomy all of these years!! It doesn't seem right.
The reason given was that other asteroids out there are as big or bigger than Pluto, and therefore Pluto is no longer justified as being singled out as a planet.
How sad....all of those Solar system science projects.....

Answer 8

pluto is no longer planet because
1) it does have much gravity to make itself into a sphere(and alll planets are supposed to spherical
2)in times it overlaps the orbit of neptune
3)its moon charon is almost its size and it is said to be a dwarf planet
now after much discusion they tell that pluto is a dwarf planet

Answer 9

Its cuz sum scientists realized there was no difinition for a planet, other than mercury, venus, earth, pluto, uranus.... So they came up with a definition, and pluto dosn't go along with it

Answer 10

It does not have a proper constant eliptical orbit like the other planets. There are also other chunks of space rock out there at least as large and it doesn't have a spherical shape like the other planets with gravity.