2007-03-30 06:06:24 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
The International Astronomical Union decided that Pluto was no longer a planet. The reason is that while Pluto is round, orbits the sun, and has three moons, it has not cleared (via gravity) its own orbit of debris. Instead, they decided to classify it as a "dwarf planet".
See the details below.
RESOLUTION 5A
The IAU therefore resolves that "planets" and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way:
(1) A "planet" [footnote 1] is 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.
(2) A "dwarf planet" is 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 [footnote 2] , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects [footnote 3] except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".
Footnote 1: The eight "planets" are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Footnote 2: An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
Footnote 3: These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.
RESOLUTION 6A
The IAU further resolves:
Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.
2007-03-30 15:19:38 · answer #1 · answered by Otis F 7 · 0⤊ 0⤋
as astronomical definitions go - Pluto is a dwarf planet now. But physically - Pluto is still the same Pluto that it was when it was considered a planet.
In my eyes - it's still a planet (although a small one) and I really think they should have settled for a definition that would add planets instead of subtract them - or even just set limits that there are only 9 planets and all the rest are KBO's (Kuiper belt objects), OCO's (Oort Cloud objects), TNO's (Trans-Neptunian Objects), or ABO's (Asteroid belt objects).
2007-03-30 13:39:09 · answer #2 · answered by Searching 4 Answers 2 · 1⤊ 0⤋
With the world the shape it's in, who gives a sh** whether Pluto is a planet or not?
2007-03-30 13:38:47 · answer #3 · answered by Chug-a-Lug 7 · 0⤊ 0⤋
I think the scientific community has discounted Pluto as a planet.
I heard it first from a TV news last year. You may want to read this article... :)
2007-03-30 13:14:04 · answer #4 · answered by dangerdizzy 2 · 0⤊ 0⤋
no. it's not considered a planet anymore.
2007-03-30 17:14:13 · answer #5 · answered by neutron 3 · 0⤊ 0⤋
it has been reclassifed as a dwarf planet
2007-03-30 13:13:45 · answer #6 · answered by Jim G 7 · 0⤊ 0⤋
nah.. it was ruled out as a planet......... long ago/
2007-03-30 13:13:05 · answer #7 · answered by puregenius_91 3 · 0⤊ 0⤋