BREAKING NEWS - IAU Vote

Anyone got a link to exactly what they have passed so I can criticise them properly?

www.iau2006.org/mirror/www.iau.org/iau0602/index.html

5A Accepted
5B rejected
6A Accepted
6B rejected

The Sun is a "Yellow Dwarf".

So there are two "Dwarfs" (or Dwarves ??) in the Solar System now.

(Not mentioning Snow White's seven).

Isn't the word "Dwarf" a bit "non-PC".

Surely we call Dwarfs (Dwarves) "vertically challenged" nowadays.

Pluto is a "Vertially Challenged" Planet.

I ALWAYS KNEW I WOULD FALL ABOUT LAUGHING AT WHATEVER NONSENSE THEY CAME UP WITH.

What a futile waste of time and effort.

So there are two "Dwarfs" (or Dwarves ??) in the Solar System now.

Actually, no. Ceres and 'Xena' are also classified as Dwarf Planets.

I'm glad you got a laugh out of it.

Dave

They never explained why?
Where is the Science in all this verbal manipulation?

So we have 5a:

The IAU therefore resolves that planets and other bodies in our Solar System be defined into three distinct categories in the following way:

(1) A planet1 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) shape2, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects3 orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".

1c is the critical point. I assume that its meant to implicitly exclude satellites. However according to the media reports it is this aspect that rules pluto out as a planet, since it impinges on neptunes orbit. If thats the case it can logically be argued that Neptune, by implication, has not cleared the neighbourhood around its orbit either.

Resolution 6b

Pluto is a dwarf planet by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.

Is therefore needed to create the fudge to exclude Pluto.

Rejecting 5B and 6B are sensible. Though I'd have preferred 6 to be rejected altogether. I don't think it ads anything.

Its easy enough to come up with nit-picking points regarding 5A. Though in our solar system I can see why its written the way it is. The IAU wanted to come up with a defintion that would have 8 planets.

So the IAU conference passes us by and we are left a little worse off than we were. The oppertunity to pass a definition based on physics was passed over in favour of a definition that preserves a classical view of the solar system. In doing so they have produced a rule that is usless for extra solar planetary descriptions; and give our poor understanding of planetary system formation may even not be useful for our solar system in the coming years.

To be honest I dont care whether Pluto is called a planet or not. Once we are consistent. One of the initial drafts simply required that a planet orbit the sun and has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape. Sure it would have given us lots of planets!, but at least its scientific and free from historic prejudice and scentimental classical views. Unfortunately the sentimental view persisted and we have a fudge of a definition to preserve it.

Pluto lasted 76 years as a planet which is longer than I think this definition will last. As our understanding of planetary systems improves with better scans of our own system as well as better data coming from extra solar planets I think there will be a push to open this pandoras box again to create a unified scientific definition.

The world must really think astronomers are just cataloguers of space at this stage. For once being a cosmologist seems a sensibile thing!

Cheers,
~Al

They never explained why?

I assume that by 'they' you mean the IAU. The IAU explained the reasoning behind the various proposals. The convened members were given the oppotunity to ask questions and make comments. Then each proposal was put to the vote.

I'm very sorry they didn't explain it to you personally and ask for your feedback before taking the vote...

As for 'verbal manipulation', there hasn't been any. There was never a definition of a planet before now.

Dave