Pluto,Is it still a planet or has it been down graded to a big rock?

Question

Pluto,Is it still a planet or has it been down graded to a big rock?

Answer 1

Officially Pluto is a dwarf planet, along with Eris and Ceres.

Eris and Pluto are also consdiered to be Plutoids.

There are many reasons why this came about - but Pluto has always been weird. Even back in 1934 a famous astronomer called Baade said Pluto was "disappointing" and more of an "asteroid" than a planet.

I can send you the paper if you like...

Answer 2

Pluto is classified in the dwarf planet category and it acts as the prototype for the plutoid category of trans-Neptunian objects, because Pluto fails to meet the condition for an object to be considered as planet, those conditions are:

1. The object must be in orbit around the Sun. (OK)

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. (OK)

3. It must have cleared the neighbourhood around its orbit. (Oops...)

Pluto fails to meet the third condition, since its mass was only 0.07 times that of the mass of the other objects in its orbit (Earth's mass, by contrast, is 1.7 million times the remaining mass in its own orbit).

Answer 3

Sorry, Pluto is not planet anymore, because it is too small, and is now considerd a drawf planet. It is too irregular, and scientists don't think it rotates around the sun. I miss Pluto!!

Answer 4

It's a Dwarf Planet.

The only real difference is that Dwarf Planets haven't cleared their stellar neighborhood of other objects.   Pluto, Eris, Ceres, and Makemake (the 4 named dwarf planets) all orbit in areas teeming with other smaller bodies, while the "real" planets have largely cleared their orbital paths of debris.

Answer 5

It's been downgraded to "larger than a bread box".

Until it gets hold of some steroids.

Answer 6

Yes it has been down graded to a planetiod which is outrages, because only planets experience seasons which they have proved that Pluto does have thanks to Hubble Space Telescope.

Answer 7

downraded

it was apperently too small

so now they just call it a huge rock surface

Answer 8

now its just a dwarf so its not really a planet

Answer 9

The IAU definition prevents Pluto from being a planet.

But Pluto is big enough to be spherical, has an atmosphere, and has 3 moons.  So it's an interesting place no matter how you classify it.

The argument that there are lots of objects out there doesn't wash.  Planets do not need to be unique.  So, in my opinion, Ceres is a planet as well as Pluto and Eris.  Though, i'd make an exception for Eris because Mike Brown doesn't want it to be called a planet, and he discovered it.

The idea that planets need to "clear their orbit" eliminates all planets.  The idea that planets need to be the "gravitational bully" eliminates all planets except Jupiter.

For me, the Moon is a planet, as is Titan, and several others.

Answer 10

Looks like someone finally understands what a "plutoid" is... the first answer hit the question right on the dot in the first sentence.

Pluto is so much more than a rock... its an icy, near perfectly spherical collection of matter with a rocky core. Its terrestrial, which means that it is basically rocky, but not a rock.

A rock is very different from a planet.

Pluto is not a true planet, but rather a plutoid.

A dwarf planet is a sub classification of a planet. A plutoid is a specific type of dwarf planet, and the terminology is limited to our solar system.

IN 2006, the IAU (International Astronomy Union) demoted poor Pluto because it was located in an asteroid belt, and also because there are many other objects in the solar system like Pluto. One was just recently added to the list of plutoids... Makemake (pronounced "Makeh Makeh") was just added, although it was discovered before... but now the IAU made it official. If Pluto was still a planet, then we would have many, many planets in the solar system. Probably over a hundred. Now, I can recite the 8 planets and Pluto in order from closest to the sun from farthest, without the help of a nursery rhyme, but after we got up to 20 I would have to memorize a very long poem.

A plutoid is basically a planet like Pluto... it meets all the criteria for it to be a planet, except it is located in an asteroid belt. Objects in an asteroid belt can't be considered planets. The asteroid belt Pluto is in, the Kuiper belt, is after Neptune, which is now the last official planet of the solar system.

And honestly, I have no idea what the order of plutoids are... so if they were considered planets, I would feel pretty embarrased.  

Answer 11

It is now called "Plutoid" and is considered a dwarf planet.