I hear that Pluto is no longer considered a Planet? why is that?

Answer 1

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

pluto is not a planet, but 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.

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.

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 not rigorous enuff. 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 in about 1850 after they found several other bodies with similar orbits, and no one thinks ceres, pallas, juno, and vesta are planets today.

incidentally, "134340 pluto" was never a moon of neptune. neptune did capture triton. this is why triton has a retrograde orbit. many astronomers consider pluto and charon to be a binary system, but two small bodies orbit that system. they are called nix and hydra

Answer 2

Pluto has several irregularitys that raised questions about it's status as an official planet.

The main problem was, they couldn't find a way to define 'Planet' in such a way to differentiate it from several other large bodys orbiting the sun. There was an attempt made to save Pluto's status, by a complex series of qualifiers that would include it and something like five other rocks that our out there. But in the end, the decision was made to go with the more exclusive deffinition of planet, so we have 8 planets instead of 14 or so.

This makes education easier, since a teacher, when they reach the 'Pluto Chapter' or whatever, can just say, "Your text books are old, Pluto is no longer a planet but we're going to talk a little bit about it and why it's not a planet anymore." Instead of having to rewrite everything including the other rocks that, frankly, no one gives a damn about.

Answer 3

On 8/24/06, the International Astronomical Union, a group of astronomers who determine names and classifications of solar objects voted to reclassify Pluto as a dwarf planet. Astronomers had found several larger object beyond Pluto and instead of calling them all planets they decided to reclassify them and Pluto. The technicality that they used was that Pluto had not swept up all the other objects in the neighborhood of its orbit. So now there are only 8 official planets.

Answer 4

Pluto is a member of the Kuiper Belt. There are hundreds of thousands of objects out in the Kuiper belt and when astronomers found a new object 2003 UB313 aka Eris it was bigger than Pluto so it came down to demote Pluto are call all of the kuiper belt objects, that are spherical, planets.

Answer 5

The scientific defnition of what a planet is was recently re-examined and a new definition created. Pluto fits all of the criteria but one: It has not cleared the neighborhood of it's orbit. Essentially that means it's not the king of the gravitational hill so to speak in the area of it's orbit. This is due to it's small size.

Remember this distinction: Pluto is technically large enough in size to be considered a planet, but it's small size makes it gravitationally poor which is the cause of its not meeting the criteria to be considered a planet. It is now classified as a dwarf planet.

Answer 6

Pluto is no longer considered a planet because it has an overlapping orbit with the planet neptune. It is also too small to be a planet. Basically, the scientists in the world screwed up, and now they are trying to cover up their mistake. But it is too late now.