why is pluto not a 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

2006-08-31 15:43:41 · answer #1 · answered by Anonymous · 3⤊ 0⤋

Because it's too small, has an eccentric orbit which lies at an angle to the plane the other planets orbit in, and there could be upwards of 50 other bodies similar in characteristics to Pluto in our solar system.

2006-08-29 12:09:23 · answer #2 · answered by DakkonA 3 · 0⤊ 0⤋

I think because they decided that since it's orbit did not coincide with the solar system's natural plane, it didn't belong as a planet. Think of the orbits as being kicked off from a central event and anything of the solar system should appear on the same axis. I'm sure that's not exact but it's pretty close......

2006-08-29 12:10:07 · answer #3 · answered by Anonymous · 0⤊ 1⤋

It is not a planet cause of its size and orbit.I shouldn't have been a planet in the first place its just some garbage that froze and became one tiny ball and then they confused it with a planet.

2006-09-01 09:01:06 · answer #4 · answered by Carlos H 1 · 0⤊ 1⤋

This link will give you a descriptive answer in why pluto is not a planet anymore
http://en.wikipedia.org/wiki/Pluto
And this link
http://nssdc.gsfc.nasa.gov/planetary/planets/plutopage.html

2006-08-29 12:12:10 · answer #5 · answered by jrealitytv 6 · 1⤊ 0⤋

Because stupid people decide it!

They mean it's a dwarf planet so it's a planet.

2006-08-29 12:07:13 · answer #6 · answered by ms. china 1 · 0⤊ 1⤋

the real question is "why was it a planet in the first place?"

2006-08-29 12:12:14 · answer #7 · answered by Anonymous · 0⤊ 1⤋

Because we live in a racist society and we don't like the Plutonians.....they're just second rate.

2006-08-29 19:34:54 · answer #8 · answered by Its not me Its u 7 · 0⤊ 1⤋

too small

too eliptical of an orbit.

2006-08-29 12:09:39 · answer #9 · answered by btownridgerunner 2 · 0⤊ 1⤋

Because it is too small.

2006-08-29 12:09:33 · answer #10 · answered by michaelsan 6 · 0⤊ 1⤋

why is pluto not a planet?

13 answers