why is Pluto not consider a plant any more?

Question

i need it for my science homework

Answer 1

Pluto was classified as the ninth planet for 75 years. But on Aug 24, 2006 the International Astronomical Union had a new definition of "planet" which does not include Pluto. Pluto isthen classified as a "dwarf planet", a class distict from "planet".

The 2006 new definition of "planet" which Pluto failed to meet the third criteria are as follows:

1.The object must be in orbit around the Sun.
2.The object must be massive enough to be a sphere by its own gravitational force. More specifically, its own gravity should pull it into a shape of hydrostatic equilibrium.
3.It must have cleared the neighborhood around its orbit.

According to the new definition, a planet is a body with sufficient mass to have "cleared the neighbourhood around its orbit and Pluto apparently doesn't have sufficient mass to perform such action owing to its relatively small size compared to other planets.

Answer 2

First of all, Pluto is (was) a planet, not a plant. You might want to spell it correctly for homework. Basically, it was the oddball of the planets. Here's some reasons:

1. The other planets were (almost totally, Mercury is a bit off) in the same plane, which means that if you had a large enough sheet of paper and laid it right through the planets, it would touch all of them, except for Pluto which travels above and below it. Because of this, Pluto is sometimes closer to the sun than Neptune.
2. Pluto is very small compared to the other planets. Mercury is the next smallest, but still bigger.
3. Pluto has a humongous moon. Compared to it, its natural satellite is way too big. Some have even considered them to be a double planet system in which they rotate around each other. Normally moons are much, much smaller than their planets.
4. I don't think this made much difference, but Pluto comes after four huge gaseous planets. The four inside, or inner, planets are rocky, and the next four or huge gas giants. (Terrestrial planets and Jovian planets). Pluto doesn't fit into either category.

Therefore, there had been talk for several years of booting Pluto from the Solar System. What finally did it in was the discovery of other objects like it. Past Neptune is a belt of objects known as the Kuiper belt. It consists of a lot of objects like Pluto. They're relatively small, icy, a long ways out, and have irregular orbits. Pluto was the first to be discovered, but many more have been found in the last 15 years. One, known unoficially as Xena, is actually larger than Pluto. Debate heatened up with the discoveries, and scientists and astronomers had to decide what to do with Pluto.

The easiest thing to do would be to say that Pluto was a mistake. However, there is some endearment around for Pluto and that would make people mad. The problem was that there was no clear definition of a planet. By the way, back in the past, Ceres was thought to be a planet. It was the first of the asteroids to be found, and was later removed. The International Astronomical Union (IAU) finally decided to make a decision and asked various people (scientists or people in their group I believe) to come up with a proposition for a definition of a planet.

The first that came up would have kept Pluto as a planet, as well as adding its moon, called Charon, and Xena, and that asteroid, Ceres. It would also have allowed many more entries over time, possibly hundreds. Try memorizing all that! It looked like this would pass, but then another idea gained support quickly. It ended up passing and disqualifying Pluto on the grounds that it hasn't cleared its neighborhood in space.

Hope this helps you out and is not too much information for your poor teacher. More information, such as the terms of the IAU's various planet definition ideas can be found at various places. I would suggest reading Pluto's article on wikipedia.com.

Answer 3

Because the scientists said that it is just a rock but it still has a core so thats y another smaller rock is in its gravitational pull (plutos moon) plus pluto doesnt have its own orbit it crosses paths with neptune so now its a "dwarf planet"

Answer 4

Pluto was never a plant.

Answer 5

i don't know the exact answer but, something along the lines of scientists discovered that it was too small to be a planet and it must be a moon that came from another solar system or galaxy.

Answer 6

too small
not the right amount of gravity
and some smart people who have nothing else better to do with their brains ( like solve some real health problems or something )
they sit around thinking about this stuff

Answer 7

do you mean planet?