[meteorite-list] And the winner is-- Plutoid!

From: lebofsky at lpl.arizona.edu <lebofsky_at_meteoritecentral.com>
Date: Wed, 11 Jun 2008 13:10:25 -0700 (MST)
Message-ID: <49707.71.226.60.25.1213215025.squirrel_at_timber.lpl.arizona.edu>

Hi All:

I will probably be going to the August meeting in Maryland, so it will be
interesting to see how this new terminology goes over.

So everything round and icy (maybe) is a Plutoid, which means Pluto-like.
Since we don't know what Pluto is (at least what to define it as), this
really makes a whole lot of sense. NOT!

I predict it will go over like a lead balloon.

Larry L.

The previous statements are the opinion of the author and may not reflect
the opinions of other scientists.



On Wed, June 11, 2008 12:58 pm, Darren Garrison wrote:
> http://www.space.com/scienceastronomy/080611-plutoid-planets.html
>
>
> Pluto Now Called a Plutoid
> By Robert Roy Britt
> Senior Science Writer
> posted: 11 June 2008
> 10:30 am ET
>
>
> Updated 2:00 p.m. ET
>
>
> Pluto's years-long identity crisis just got more complex today.
>
>
> The International Astronomical Union has decided on the term "plutoid" as
> a name for Pluto and other objects that just two years ago were redefined
> as "dwarf planets."
>
> The surprise decision is unlikely to stem ongoing controversy and
> confusion, astronomers say.
>
> Sidestepping concerns of many astronomers worldwide, the IAU's decision,
> at a meeting of its Executive Committee in Oslo, comes almost two years
> after it stripped Pluto of its planethood and introduced the term "dwarf
> planets" for Pluto and other small round objects that often travel highly
> elliptical paths around the sun in the far reaches of the solar system.
>
> "Most of the people in astronomy and planetary science community had no
> idea this was going to come out," said Hal Weaver of the Johns Hopkins
> University
> Applied Physics Laboratory. Weaver called the new definition "sort of
> outdated, outmoded, archaic."
>
> A meeting in August at the Applied Physics Laboratory is slated to debate
> the entire topic of defining planets. Meanwhile, other astronomers said
> the new definition needed more definition or that it might simply not be
> used.
>
> "This seems like an unattractive term and an unnecessary one to me," said
> David
> Morrison, an astronomer at NASA's Ames Research Center who, in 2006, said
> the IAU's actions on Pluto have created major rifts among astronomers.
>
>
> The new definition
>
>
> The name plutoid was proposed by the members of the IAU Committee on
> Small Body
> Nomenclature (CSBN), accepted by the Board of Division III and by the IAU
> Working Group for Planetary System Nomenclature (WGPSN), and approved by
> the IAU Executive Committee at its recent meeting in Oslo, according to a
> statement released today.
>
> Here's the official new definition:
>
>
> "Plutoids are celestial bodies in orbit around the sun at a distance
> greater than that of Neptune that have sufficient mass for their
> self-gravity to overcome rigid body forces so that they assume a
> hydrostatic equilibrium (near-spherical) shape, and that have not cleared
> the neighborhood around their orbit."
>
> In short: small round things beyond Neptune that orbit the sun and have
> lots of rocky neighbors.
>
> The two known and named plutoids are Pluto and Eris, the IAU stated. The
> organization expects more plutoids will be found.
>
> "Rather than resistance to 'plutoid,' I think we'll just be hearing
> groans," said Stephen J. Kortenkamp, senior scientist at the Planetary
> Science Institute
> in Tucson.
>
> Controversy continues
>
>
> One IAU leader recognizes it is adding to an ongoing controversy.
>
>
> The IAU has been responsible for naming planetary bodies and their
> satellites since the early 1900s. Its decision in 2006 to demote Pluto was
> highly controversial, with some astronomers saying simply that they would
> not heed it and questioning the IAU's validity as a governing body.
>
> "The IAU is a democratic organization, thus open to comments and
> criticism of any kind," IAU General Secretary Karel A. van der Hucht told
> SPACE.com by email
> today. "Given the history of the issue, we will probably never reach a
> complete consensus."
>
> Van der Hucht said the new designation is not a further demotion for the
> once-favorite planet of grade-school children: "Pluto is now the prototype
> of a very interesting category of outer solar system bodies."
>
> IAU Division III President Edward L.G. Bowell of the Lowell Observatory
> said the ruling stems from unfinished business from the forging of a
> planet definition in 2006. Bowell said there is no agreed-upon way to
> define "dwarf planet" yet, so "officers of the IAU thought it would be a
> good idea to adopt alternative criteria that would at least allow those
> large bodies to be named as though they were dwarf planets."
>
> It remains to be seen whether astronomers will use the new term.
>
>
> "My guess is that no one is going to much use this term, though perhaps
> I'm
> wrong," said Caltech astronomer Mike Brown, who has led the discovery of
> several objects in the outer solar system, including Eris. "But I don't
> think that this will be because it is controversial, just not particularly
> necessary."
>
> Brown was unaware of the new definition until the IAU announced it today.
>
>
> "Back when the term 'pluton' was nixed they said they would come up with
> another one," Brown said. "So I guess they finally did."
>
> Reactions were not all negative, however.
>
>
> "It seems like a reasonable decision to me, and given the excitement
> generated by New Horizons [a NASA probe headed for Pluto], it's in
> everyone's interest to favor the largest Kuiper belt objects with their
> own categorical designation," said Gregory Laughlin, a University of
> California, Santa Cruz extrasolar planet
> researcher.
>
> "The only fly in the ointment that I can envision is if a plutoid larger,
> than, say, Mars is detected," Laughlin points out. "In that case, I think
> we'd see a big flare-up of the what-is-a-planet debate."
>
> More debate coming
>
>
> The dwarf planet Ceres (which used to be called an asteroid, and before
> that was called a planet!) is not a plutoid as it is located in the
> asteroid belt between Mars and Jupiter, according to the IAU. Current
> scientific knowledge lends credence to the belief that Ceres is the only
> object of its kind, the IAU stated. Therefore, a separate category of
> Ceres-like dwarf planets will not be
> proposed at this time, the reasoning goes.
>
> Weaver, the Johns Hopkins researcher, has helped organized a meeting,
> planned earlier this year for Aug. 14-16 at Johns Hopkins University
> Applied Physics
> Laboratory, that aims to bring astronomers of varying viewpoints together
> to discuss the controversy.
>
> "We're not trying to slam the IAU, it's just that we also don't want to
> lead people to the idea that there's a handful of people who decide where
> science should go," Weaver said today. The meeting is designed to "address
> this question in terms of a scientific conference." He said no votes will
> be taken at the meeting. Rather, it's a time to "sit back and take stock
> of everything we've learned in the past couple of decades."
>
> The term plutoid joins a host of other odd words -- plutinos, centaurs,
> cubewanos and EKOs -- that astronomers have conjured in recent years to
> define objects in the outer solar system, whose appearance seems to grow
> more complex every year.
>
> Kortenkamp wonders if "plutoid" isn't just one more confusing term in the
> cosmic lexicon.
>
> "So Pluto is a Kuiper belt object, a plutino (the unofficial but nearly
> universally accepted name for objects in the 2:3 resonance with Neptune),
> a dwarf planet, and now also a plutoid?" he said. "If the IAU is trying to
> make things more clear, I think it needs to try again. This is just
> another layer of confusion that will feed the "pluto is a planet" camp at
> the [Johns Hopkings] meeting."
>
> Kortenkamp also thinks the new defiinition leaves Ceres up in the air:
> "And this
> "-oid" classification doesn't apply to Ceres?" he asks. "Okay, so does
> that means we continue calling Ceres an ASTERoid?"
>
> Asked if Ceres remains a dwarf planet and is not an asteroid, Bowell, the
> IAU
> official, said: "I think so!"
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Received on Wed 11 Jun 2008 04:10:25 PM PDT