[X] My Assistant

[Guest_Kevin Heider_*]

I had assumed that 1 Ceres was still considered an Asteroid since it orbits in the asteroid belt and has the same origin as the other asteroids.

But I noticed that on wikipedia they say: "Ceres is a 'dwarf planet', and may no longer be classified as an asteroid."

Wikipedia cites the IAU website at http://www.iau2006.org/mirror/www.iau.org/...u0603_Q_A2.html that states:
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Q: What is Ceres?

A: Ceres is (or now we can say it was) the largest asteroid, about 1000 km across, orbiting in the asteroid belt between Mars and Jupiter. Ceres now qualifies as a dwarf planet because it is now known to be large enough (massive enough) to have self-gravity pulling itself into a nearly round shape. [Published reference for shape of Ceres: P. Thomas et al. (2005), Nature 437, 224-227. Dr. Peter Thomas is at Cornell University.] Ceres orbits within the asteroid belt and is an example of a case of an object that does not orbit in a clear path. There are many other asteroids that can cross the orbital path of Ceres.

Q: Didn’t Ceres used to be called an asteroid or minor planet?

A: Historically, Ceres was called a “planet” when it was first discovered (in 1801) orbiting in what is known as the asteroid belt between Mars and Jupiter. Because 19 th century astronomers could not resolve the size and shape of Ceres, and because numerous other bodies were discovered in the same region, Ceres lost its planetary status. For more than a century, Ceres has been referred to as an asteroid or minor planet.
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Is Ceres still classified as an asteroid since it is located in the asteroid belt? Pluto is a Kuiper Belt Object (KBO) even though it is also a 'dwarf planet'.

Has Pallas become the 1st asteroid discovered? Has Vesta become the largest asteroid (at least until the IAU decides that since Vesta is a damaged, differentiated protoplanet that it was probably spherical in the past)? *IF* Ceres is truely no longer an asteroid, because it is spherical, then those two very basic questions have new answers!

How do we contact the IAU for an official statement on the classification of Ceres as an asteroid?

-- Kevin Heider

[gpurcell]

The real issue I see here is a fundamental misuse of science.

The question "What is a planet?" is not a scientific question! There is no Platonic "planetness" out there which can serve as a referent. Any "tests for planetness" are simply an application of more-or-less arbitrary boundary conditions.

What bothers me so much about this is that we see scientists, who for various reasons believe something, employ an argument from authority as opposed to a scientific inquiry on the subject. Of course, they have to do this--a scientific inquiry into the meaningness of the word "planet" would quickly descend into philosophy.

Anytime, anytime I see argument from authority it makes me question the agenda and motives of those making the spurious call. It is particularly obnoxious in science because the whole point of the enterprise is that truth claims can be tested without reference to the individual making the claim.

If an astrobiologist claims that certain tests prove life on Ganymede, the testing procedure can be examined and duplicated. Independent inquiry will settle the truth value of the claim.

THERE IS NO TRUTH VALUE TO THE IAU'S POSITION. IT CANNOT BE TESTED. It is SIMPLY a statement of opinion...and the underhanded and devious manner with which it was arrived at suggests, strongly, that the motives behind those pushing the demotion of Pluto are not good.

[JRehling]

What bothers me so much about this is that we see scientists, who for various reasons believe something, employ an argument from authority as opposed to a scientific inquiry on the subject. Of course, they have to do this--a scientific inquiry into the meaningness of the word "planet" would quickly descend into philosophy.

This aspect of it, quite apart from any specific worlds we are talking about, bothers me a great deal and I think loses scientists a lot of "capital" in terms of winning the masses over to a greater interest in science.

A particularly annoying (though brief) moment in my own education that I recall: An English teacher was talking about a mirror (which I imagine was mentioned in a story; that, I don't recall) and asked the class: "What does a mirror do?" He got several answers: "They reflect light." (Teacher shakes his head 'no'.) "They create an image of something else." (Teacher shakes his head 'no'.) "They create a reverse image of something else." (Teacher shakes his head 'no'.) After everyone with gumption had given up, the teacher let a silence hang in the air for a while. Then he said, "Nothing. A mirror does nothing."

Well, he was free to go ahead and make whatever point he was making, but overall, that minute of classtime was an exercise in jackassery on his part. The real upshot was that no matter how valid an answer was, he was going to shake his head 'no' and stymie everyone before giving his answer, which wasn't any better than anyone else's. At worst, his answer was technically wrong. At best, it was one of several valid answers. But given the moment and his magisterial status (and his generally antisocial personality), he was determined to shoot everyone else down.

The greatest disservice that teacher did was to teachers who actually had a REASON for saying some answers were right and some wrong.

And that's what we have with the 2006 IAU definition. The public is being told that scientists know best (which in many cases they do) when this is really an aesthetic matter and at BEST is an arbitrary selection being introduced for the purpose of adopting some standard, any standard. At worst, it's an arbitrary selection being introduced out of a slavish adherence to aristotelian categories that are vertically hierarchical while mutually exclusive within the same level of the tree -- an assumption that everyone knows does not work well in many cases.

This spends goodwill capital that burns up a little of the eagerness the public might have for enjoying this interesting subject matter, all for the no-gain adoption of a formal definition for which it is inconceivable that science will profit. (Can we imagine riddles of the formation of the asteroids that were once hard to understand but are now laid bare by clarity regarding Ceres's category? Not possibly.) Lose-lose. This would all be true even if Pluto had never existed.