Why isn't Pluto a planet anymore?

Question

I know people already asked this question but the answers arent clear enough! Please say (seriously) in simpler words!

Answer 1

This is what really happened. Scientists discovered a planet out there that is larger than Pluto. They started asking themselves "Well, we've found this planet. Now what? It's larger than Pluto , so should Pluto even still be a planet?" So they made a new way of organizing the planets. They organized Pluto into a "semi-planet" or a dwarf planet. It is now, more or less, an object of the Keplar belt. And there you have it. Hope this helped.

Edit to Anonymous: Pluto is NOT a proto-planet. Protoplanets are moon-sized planet embryos within protoplanetary discs. They start out sort of like what venus looks like, but not exactly. They are mostly lava and molten rock. It becomes a planet later on.

Answer 2

Well for starters, Pluto is just too small. In the neighborhood where Pluto lives? Planets are supposed to be huge. The Jovian planets, Jupiter, Saturn, Uranus and Neptune are 20 to 300 times the size of the Earth, and Pluto is really small compared to the Earth, smaller than our Moon. Kind of stands out.

And Pluto is not made out the same material as the Jovians. The large planets are mostly gigantic spheres of gas, mostly hydrogen and helium. Likely there are no solid surfaces, only denser and denser gas all the way in. Pluto is a small solid world of methane, water, carbon dioxide and ammonia ices, maybe a little rock and with a just hint of atmosphere (that freezes out and falls as snow in her "winter").

And third, Pluto's orbit is the most eccentric (oval shaped) and the most tilted to the plane that the rest of the planets orbit in. Also, Pluto is locked in a resonance with Neptune's orbit and comes closer to the sun than Neptune sometimes.

There were theories that Pluto was a lost moon of Neptune but that was before we discovered she a has one large moon (Charon) half her size (pretty much, this system is a double planet) and recently two other teeny-tiney moons.

Pluto seems like she cant be an ejected moon-she must have formed on her own and seems to be part of an entire army of small icey-dwarf objects that circle just outside Neptune's orbit in what is known as the Kuiper belt. We have no idea of how many or how large these objects may be. NOT "planets" proper, hence the new term "dwarf planet" where Pluto is king.

BUT I still think Pluto should be called a planet because of historical reasons (discovered by an American, financed by Percival Lowell, Tombaugh's life story, etc).

Answer 3

The definition of a planet had to be changed, and the International Astronomical Union, which is the referee in such matters, did so. Several objects have been found which have at least as much claim to planethood as Pluto does, so it was either add them to the list or take Pluto off the list. After much headscratching about what it really means to be a planet, they decided that neither Pluto nor the new objects really qualified, and Pluto got dropped.

Answer 4

The International Astronomy Union defined the term "planet" scientifically. Pluto does not have the necessary dimensions and characteristics to be a planet; however it is to big to be an asteroid and has a natural satellite too.

So, Pluto becomes a dwarf planet, along other Trans-Neptunian objects like Eris (another dwarf planet and bigger than Pluto) and Sedna.

Answer 5

In simple words, science re-classifies things all the time. A new spider is found in the Amazon and at first they classify it as a Tarantula. Then 10 years later they find others that are more like the new spider than Tarantulas. So, they make a new classification for the new family of spiders. The original now becomes part of that family, instead of the Tarantula family.

I don't know why everone gets upset over Pluto. It is a much more exciting object now.

Answer 6

To be classed as a planet, Pluto would have to clear the space around its orbit. Pluto does not have enough gravity to properly clear its orbit out like bigger planets do (bigger planets clear their orbits by sucking in other objects or throwing them out of the way), and so Pluto has been reclassified as a dwarf planet.

Answer 7

Corrie, your an idiot.

It's been re-classified as a "proto-planet" which means it's too small to be a "planet". The definition of a planet was agreed upon a few years back and the requirements were not met by Pluto.

Answer 8

It's to small and doesn't have the qualifying characteristcs to be a planet. Plus it's more in the Kieper belt area. They have found asteriods in the Kieper belt that are bigger than Pluto. Pluto is considered a Dwarf Planet.

Answer 9

Because scientist discoverd that pluto is only a huge block of ice they are saying that pluto's moon might even be a new planet but who know's

Hope it help's ;)

Answer 10

Pluto, in essence is a comet, knocked out of the Oort cloud, where cometary material hovers around our solar system, it got caught by Neptune's gravity, and set in an irregular elliptical orbit around the sun