Pluto remains a Planet, or is that a Pluton? Good luck if you can understand them

[ballaratdragons (Ken)]

The announcement is out!

Pluto remains as a Planet! or is that a Pluton?

And Ceres the asteroid is about to become a Planet/Pluton too. They are now hinting at 12 Planets!!!

Read todays report and see if you can make heads or tails of it:

http://www.iau2006.org/mirror/www.ia...1_release.html

[ballaratdragons (Ken)]

This is what they say:

"If the proposed Resolution is passed, the 12 planets in our Solar System will be Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon and 2003 UB313".

Charon is a Moon of Pluto!!!! and Ceres is a potato shaped Asteroid!

Oh well, they are the experts.

[AstroJunk (Jonathan)]

And how naff is "Pluton"

[ballaratdragons (Ken)]

Yeah, what happened to the term Planetoid?

Why even differentiate at all. They say they will be 12 planets, but called some of them Plutons!

Glad none of them are Hemispherical Planetoids. They probably would have called them Hemiroids

[Don Pensack]

"A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet."

This is the definition being voted on. Immediate members added would be Ceres, Charon, and Xena, but other candidates for consideration would be Chiron, Sedna, Quaoar, Pallas, Juno, Santa, etc, totaling 23 to39 depending on determination of a round shape.
Well, when faced with new data, science changes its formulae. That's the way it should be.
It should be noted that the entire IAU hasn't approved this definition, yet, so this might not be the adopted definition.

[ballaratdragons (Ken)]

I agree that science must keep up to date with changes Don, but Charon does not fit the category.

is neither a star nor a satellite of a planet."

Charon (also known as Pluto 1) is a satellite of Pluto, is it not?

All a bit confusing at the moment. I hope they clarify the proposal a bit more.

[Don Pensack]

Apparently, Charon would be included because Pluto-Charon would be considered a "double planet". I find that strange, as this would open the door to include Luna as a planet, too. We'll see what happens.

[ballaratdragons (Ken)]

Hmmmm, very interesting point Don.

What ever happens, Science & Astronomical books are about to be re-written. It's watching more history being made before our eyes. Exciting in a way!

[ballaratdragons (Ken)]

From WikiPaedia:

"Charon has been a part of the controversy over Pluto's status as a planet. Under the latest proposal, which will be decided on August 24, 2006, the International Astronomical Union may classify Charon as a pluton, officially making Charon a planet. Under this proposal, Charon would be considered a binary planet with Pluto since the two orbit each other around a center of mass that is outside either body."

[ving (David)]

pluto-charon a double planet? i have never heard such rubbish!!

i'd have thought sedna would be a definite tho...

[robagar]

If you don't like "double planet", how about "co-moons" instead?

[mickoking]

Charon a planet? I think not. And Ceres is only the size of Mare Crisium, fair dinkum . Only 2003UB313 deserves planet status IMHO

[spacezebra (Petra)]

Wow! that was fast


Pluto is a dwarf planet (once classified as a true planet) in the solar system and the prototype of a yet to be named family of Trans-Neptunian objects.

Cheers Petra

[ving (David)]

yup fast alright!@

A trans-Neptunian object (TNO) is any object in the solar system that orbits the sun at a greater distance on average than Neptune. The Kuiper belt, Scattered disk, and Oort cloud are names for three divisions of this volume of space. Pluto and its moon Charon are trans-Neptunian objects.

[Sonia]

The scientists agreed that for a celestial body to qualify as a planet:

• it must be in orbit around the Sun
• it must be large enough that it takes on a nearly round shape
• it has cleared its orbit of other objects

Pluto was automatically disqualified because its highly elliptical orbit overlaps with that of Neptune. It will now join a new category of dwarf planets.

Pluto is no longer a planet because of it overlapping Neptunes orbit.

[Greg Bryant]

Pluto's real disqualification was because it was in an orbital zone shared by hundreds of other fellow Kuiper Belt Objects - the zone hadn't been cleared.