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Pluto the Red-headed Dwarf Planet March 9, 2009

Posted by baldricman in astronomy, News.
Tags: , , , , , ,

Many of you will remember the debacle in 2006 about the (finally) successful attempt at reclassifying Pluto, “demoting” it as it were, from a planet to, well, not a planet. The International Astronomical Union (IAU) voted* to reclassify Pluto, originally the ninth planet in our solar system, relegating it to a “Dwarf Planet”. (I’m not even sure that term is politically correct, but moving on)

* Voted in “majority”, though many felt the vote, which was delayed until the last day of the 2006 conference when most visiting astronomers were not present, was more an ambush – only 4% were present for the proposal, by arrangement, some theorise, and no absentee votes were allowed

The US state of Illinois, however, has declared March 13 as “Pluto Day”, and officially declared Pluto as a planet. They have decided to simply disregard the IAU’s decision (read about it here). It turns out the guy who first discovered Pluto, one Clyde Tombaugh, was in fact born in Illinois….

I’ll keep my opinions on the classification to myself, but one thing I will say is that the reactions, justifications, and general politicking of many of the involved scientists seems rather, well, un-academic (for want of a better word). I’m well aware that scientists are also (mostly) human, and as such are susceptible to passions, pride, the need for job security (and of course funding), and the general arrogance that so often accompanies intellectuals, and indeed I feel that some scandal in these circles is probably a good thing (every so often, as history will agree), but it really is a little disconcerting when they let it all hang out like this.

Although this is just a nomenclature issue, it still reminds me to be extra wary (more so than before) of what “science” cries, especially when so loudly. It reminds me just how fluid the views of “fact” are in science (perhaps not without good reason).
I guess sometimes the “bosses of science” need to just make a decision, name something a something, call a half-truth a truth, name a theory without a better alternative as fact, all in the interests of Joe Public’s understanding.


1. Laurel Kornfeld - March 9, 2009

Forget the “finally”; the IAU did not “successfully” reclassify Pluto. In a process that violated their own bylaws, four percent of the IAU bungled the issue terribly and came up with an essentially useless planet definition. That is why the debate over Pluto’s status is far from over and why more than just the state of Illinois have decided to ignore the IAU’s decision.

The Illinois legislature has way more sense than the International Astronomical Union has shown in two-and-a-half years. It’s the IAU who have acted like idiots, with one tiny group forcing a nonsensical planet definition on everyone. The truth is there is NO scientific consensus that Pluto is not a planet. The criterion requiring that a planet “clear the neighborhood of its orbit” is not only controversial; it’s so vague as to be meaningless. Only four percent of the IAU even voted on this, and the vote was driven by internal politics. A small group, most of whom are not planetary scientists, wanted to arbitrarily limit the number of planets to only the largest bodies in the solar system. They held their vote on the last day of a two-week conference with no absentee voting allowed. Their decision was immediately opposed by hundreds of professional astronomers in a formal petition led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto.

Stern and like-minded scientists favor a broader definition of planet that includes any non-self-luminous spheroidal body orbiting a star. The spherical part is key because when objects become large enough, they are shaped by gravity, which pulls them into a round shape, rather than by chemical bonds. This is true of planets and not of shapeless asteroids and comets. And yes, it does make Ceres, Eris, Haumea, and Makemake planets as well, for a total of 13 planets in our solar system.

Even now, many astronomers and lay people are working to overturn the IAU demotion or are ignoring it altogether. Kudos to the Illinois Senate for standing up to this closed, out of touch organization whose leadership thinks they can just issue a decree and change reality.

baldricman - March 10, 2009

Hi Laurel, thanks for stopping by, and for your input.
Just to clarify my meaning of “finally”: I meant that a certain small group of scientists had been slowly gaining momentum over the past years in trying to demote Pluto’s status, and at last they succeeded (albeit by highly questionable means)
On the “clearing its orbit” definition: I think beyond its vagueness and controversial nature, its simply illogical. It largely disregards the possibility for same-mass objects sharing an orbit, as well as “lowering” the potential for any bodies with highly elliptical orbits (such as Pluto, as one example). Its almost as if they think ALL star systems’ “planets” will look like a nice, junior-school concentric-ring model 🙂 🙂
Maybe they do…..

2. Allen - March 11, 2009

Several points here. First, there had never been a formal definition of ‘Planet’ until the IAU’s decision was reached. Up till then, a Planet was a Big Thing orbiting a star, unless it wasn’t very big but we decided to call it a planet instead of an asteroid. Sometimes we had smaller things and we called them asteroids. The distinction was totally arbitrary. Some of the larger asteroids aren’t really distinguishable from the smaller planets. Some of the MOONS are bigger than some of the planers. As more and more new bodies were discovered, the more ridiculous the situation became. Technically, all that the IAU did was to choose and settle on a first-time definition to explain what exactly is meant by the word “Planet”

Second, the manner in which the decision was reached was (as stated by all posters so far) a clever bit of political maneuvering. It was not a popular motion, and the vote was constructed with built-in bias.

Third: If Baldricman thinks that the process wasn’t academic, then he clearly doesn’t know many academics! Despite their lofty claims to the contrary, scientists and academics can be some of the most petty, bitchy and politically minded people on the planet. Anybody who has the experience to be able to compare working in a university environment to working in a corporate (or even government) environment knows what I’m talking about!

Fourth: It is not scientifically important. It’s a taxonomical issue, not an astronomical one. I dont’ understand how people have become so emotionaly involved on the issue that they feel there’s something which needs complaining about. Nothing has changed except the name. But then names are always a highly charged subject. When the government renames “Main Street” to the multisyllabic name of a violent killer who happened to be on their side in the revolution, people get upset. When, 50 years later, the new government scraps that name in favour of some new crony, people get upset all over again. At least with street names, they’re able to come up with rational arguments (“It will be expensive to replace the signposts”). Pluto has no signposts!

baldricman - March 11, 2009

Thanks for your comments Allen!
Regarding the “un-academic” comments, I was referring to the reactions after the fact, not to the process of the vote. But your point is taken, and we are in agreement. And I can be idealistic can’t I? 😉
And, yes, it is a nomenclature issue (or taxonomical) and “not scientific”, but much of science’s very basis is the categorisation of “things” into similar groups, really. These groupings are what allow us to draw conclusions and make assumptions, which are the starting point for theories, which in turn (occasionally) lead to proofs. (Of course its all iterative…)
Scientists think about the universe etc. (see philosopy), and put the results into human-relevant and understandable terms (and to “categorise is human” *coff*)
Names are important to us plebs. We like to know whats what. (Like, we like to know about what keeps us on the earth, and what keeps aeroplanes in the air….. irony intended…)

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