If Pluto is no longer a planet, then what is it classified as?

Question

I don't want to know it's new name because all they're calling it now is a number. I want to know is it a STAR, COMMET, ASTEROID....?

Answer 1

A dwarf planet.

The IAU members gathered at the 2006 General Assembly agreed that a "planet" is defined as a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

This means that the Solar System consists of eight "planets" Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A new distinct class of objects called "dwarf planets" was also decided. It was agreed that "planets" and "dwarf planets" are two distinct classes of objects. The first members of the "dwarf planet" category are Ceres, Pluto and 2003 UB313 (temporary name). More "dwarf planets" are expected to be announced by the IAU in the coming months and years. 


Aloha

Answer 2

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).

But opponents of Pluto's demotion remain unconsoled and have generated a thriving industry in T-shirts, mugs and other memorabilia. Among the many slogans of this movement was one which played on the mnemonic for the names of the erstwhile nine:

Answer 3

http://www.iau.org/fileadmin/content/pdfs/Resolution_GA26-5-6.pdf

pluto is not a planet, but pluto orbits the sun, is round, does not have an isolated orbit (a bunch of other similar bodies have similar orbits.), and is not a satellite so it is a dwarf planet. this does not change anything about the solar system or pluto. it just corrects the mistake of classifying pluto as a planet initially.

this same thing has happened before. beginning in 1800, astronomers found a few bodies orbiting between the orbits of mars and jupiter, and they finally stopped calling them planets after the fourth discovery. astronomers then added numerals to the names, and pluto recently got its numeral. 150 years from now, no one will think of "134340 pluto" as a planet. very few will even know we classified it as a planet. "1 ceres" and "136199 eris" are other dwarf planets.

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 illogical and "out of place". this was the right thing to do, believe me. i don't understand why so many are having such a problem with this.

i don't know how long this will drag on tho. many planetary scientists are not satisfied that the definition is rigorous enough.

http://en.wikipedia.org/wiki/Dwarf_planet
http://en.wikipedia.org/wiki/1_Ceres
http://en.wikipedia.org/wiki/Pluto
http://en.wikipedia.org/wiki/Eris_%28dwarf_planet%29

Answer 4

Pluto was defined as a dwarf planet. If this wasn't done, then other objects in space would have had to been defined as planets (including, I believe, one of the moons of Jupiter. And that simply wouldn't make sense!) even though they're not. It's stupid to name it a "dwarf _planet_" when it isn't a planet anymore, though.

Poor pluto. :(

Answer 5

Kuiper Belt Object,Trans-Neptunian Object,Dwarf Planet.

Answer 6

It's officially a dwarf planet, but more precisly a TWIN dwarf planet, because its "moon" Charon is not really a moon because the center of gravity is not WITHIN Pluto, but in the empty spece BETWEEN them, so Pluto and Charon actually comprise a BINARY SYSTEM.

In fact, as you say, Pluto now has a number like non-planetary bodies, Its official name is "134340 PLUTO".

Answer 7

A dwarf planet and also a Kuiper Belt Object (KBO).

Interestingly enough, once they created the dwarf planet classification there was a dwarf planet in asteroid belt I never knew existed was announced (although it was discovered a long time ago), named Ceres. Ceres is the only dwarf planet in the inner solar system so it is not considered a KBO.

Answer 8

Pluto is now classified as a dwarf planet.

Answer 9

Dwarf planet

Answer 10

A dwarf planet...actually it has been given an asteroid number, so technically it's an asteroid.