Is pluto a planet?

Question

is pluto a planet?
Why or why not

Answer 1

nope in November 06 the International Astronomical Union came up with a definition for a planet and unfortunately Pluto did not match the Definition

Answer 2

here's an easy and simple defination!
Pluto is not a planet anymore, A planet has some physical properties that are different from other moving objects in the space. Pluto has only one property of those three propertires/characterstics of the planets. the three characterstics of planets are:
1.) it should rotate on a fixed axis, in a fixed time period and in a relevent manner.
2.) it should clear its surroundings, i.e. it should not have other space objects arround it.
3.) A planet should have a hard, rigid surface.

Pluto has one one property i.e. it has a fixed axis and orbit but has not cleared its surroundings, it has many other small objects surrounding in its neighbour. Pluto also does not have a rigid body, it has a smooth cloudy surface.
so by study it has shown that it has only one characterstic of three so it should be called half planet or a Planetoid.

Answer 3

Pluto is a dwarf planet, because the International Astronomical Union said so. At their 2006 meeting, they passed this resolution:

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" 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, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects, except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".

1 The eight "planets" are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
2 An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
3 These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.


IAU Resolution: Pluto

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.

Answer 4

It has been reclassified a dwarf planet because it is so small, and partly because it is in a slightly odd orbit. We always knew the orbit was, odd, but didn't know exactly how small it was until recently.

Answer 5

this is really a question of semantics. what is your definition of a planet? is it based on size? orbit shape? satellite bodies?? call Pluto a planet if you want, don't get bogged down in the details of semantics

Answer 6

It looks like you are going to have to accept its new designation as a dwarf planet.

Answer 7

Pluto is a planet.
http://www.solarviews.com/eng/pluto.htm

Answer 8

it's now considered a dwarf planet.

http://en.wikipedia.org/wiki/Pluto

Answer 9

It's not in 'The New Solar System'.

Answer 10

Not anymore - too small.