Since Pluto is no longer a planet, what is its official category now?

Question

What should we be calling Pluto? And what should we be calling Charon now?

Answer 1

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.

Answer 2

It's still a planet - a 'dwarf planet'. If the International Astronomical Union can't even make up it's mind as to whether Charon is a satellite or a dual-dwarf planet (with Pluto) while changing all their definitons, then I'll be buggered if I know... Sorry!

Answer 3

Actually, in my opinion, none of the above is correct. If we go by the new definition voted in by the IAU, only Mercury and Venus qualify as planets, so there are now only two. Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, have not cleared their orbital paths which is one of the new criteria for planets. It seems likely that the IAU will reject this definition which was voted upon with not even a quorum at the last meeting. If they go back to the definition that was introduced at the start of the meeting, we are looking at 14 or more planets which also seems unacceptable, therefore the original 9 should stand until a suitable definition is agreed upon.

Answer 4

You can call Pluto "Pluto", and Charon "Charon". Both are now known as minor or dwarf planets as one can consider Pluto-Charon a double dwarf planet, or Charon as the moon of a dwarf planet.

Answer 5

Dawrf Ice Planet

Answer 6

Dwarf planet.
Mathematical rules/boundaries are needed to tell what's a planet or dwarf planet, etc. Right now, it's a mess and totally arbitrary specs are looked at.

Answer 7

No matter what anyone else says, there is only one James Bond and that's Sean Connery.

No matter what anyone else says, Pluto is a planet to me and always will be.

Answer 8

It is now a Dwarf Planet with the "name" of 134340.

See this website: http://www.npr.org/templates/story/story.php?storyId=5631291

Answer 9

Now it's just a cartoon dog that Walt Disney created.

Answer 10

It's just another solitary, celestial body on the outside looking in.