[meteorite-list] Defining 'Planet': Newfound World Forces Action

From: Dawn & Gerald Flaherty <*grf2_at_meteoritecentral.com*> Date: Tue Aug 2 21:18:14 2005 Message-ID: <027401c597c9$2d8b9430$6502a8c0_at_GerryLaptop> · grf2_at_meteoritecentral.com

---
>
> A Revolution
>
> A swarm of small worlds discovered in recent years is remaking our view
> of the solar system, astronomers agree. Pluto, once an oddball, is now
> thought to be one of many round objects out there.
>
> "It's really a revolution," says Alan Stern of the Southwest Research
> Institute. "We are finding out just how quaint our view of the solar
> system was."
>
> Improved technology promises more discoveries. Some astronomers won't be
> surprised if something as big as Mars, or even Earth, is found way out
> there but still bound to the Sun. So far, only a fraction of objects
> thought to be in the Kuiper Belt, beyond Neptune, have been found.
>
> Stern, who is managing NASA's New Horizon's mission to Pluto, points out
> that there is a billion times more space in our solar system beyond the
> Kuiper Belt compared to inside that region.
>
> "Hold onto your hat," he said. "It's just going to get more bizarre."
>
> --Robert Roy Britt
>
> --------------------------------------------------------------------------
-
>
> But practically speaking, Marsden, who expects it will take "somewhat
> more than a week or two to come up with a policy," prefers another
approach.
>
> "The only sensible solution is to accept that the solar system contains
> the eight planets known a century or so ago," Marsden said via email,
> "and to add new members only if they are larger than, say, Mars -- or
> maybe even the Earth."
>
> (Stern and others contend that such large worlds indeed await discovery.)
>
> The discovery of 2003 UB313 presents "the best chance to resolve the
> problem," Marsden said. "I doubt that all astronomers will be happy with
> the outcome, but I would hope that what is decided is enough of a
> compromise that most of them are."
>
> Forget science
>
> Mike Brown yesterday attempted to shift the whole debate away from
science.
>
> In Brown's mind -- and he admits to changing it recently -- Pluto is too
> enshrined in our culture, from place mats to postage stamps, to strip it
> of planethood.
>
> "Some astronomers have rather desperately attempted to concoct solutions
> which keep Pluto a planet, but none of these are at all satisfactory, as
> they also require calling dozens of other objects planets," Brown wrote
> on his web site this week. "While people are perhaps prepared to go from
> nine to 10 planets when something previously unknown is discovered, it
> seems unlikely that many people would be happy if astronomers suddenly
> said, 'we just decided, in fact, that there are 23 planets, and we
> decided to let you know right now.'"
>
> Brown's team is taking a stand.
>
> "We declare that the new object, with a size larger than Pluto, is
> indeed a planet," Brown wrote. "A cultural planet, a historical planet.
> I will not argue that it is a scientific planet, because there is no
> good scientific definition which fits our solar system and our culture,
> and I have decided to let culture win this one."
>
> He advises the public to "ignore the distracting debates" of the
scientists.
>
> It seems clear the IAU Working Group plans to ignore Brown, at least
> insofar as they expect to forge a scientific definition.
>
> Yet no matter what the group comes up with, you can bank on at least one
> more year of debate. For a definition to be made official, it must be
> voted on at an IAU General Assembly meeting. The next one is in Prague
> in August, 2006.
>
>
>
============================================================================
>
>
> http://news.bbc.co.uk/1/hi/magazine/4737647.stm
>
> Farewell Pluto?
> By Alexis Akwagyiram
> BBC News
> August 2, 2005
>
> The discovery of a new planet in our Solar System could have an
> unintended consequence - the elimination of Pluto in the list of planets
> everyone has in their heads. Is it time to wave this distant, dark piece
> of rock farewell?
>
> To the casual observer, the announcement that scientists have identified
> a tenth planet orbiting the Sun is primarily of importance to few people
> other than science teachers and schoolchildren.
>
> But, on closer examination, the revelation may have more far-reaching
> consequences for the way in which we think about space.
>
> At around 3,000km across, 2003 UB313 - as it has been named - is the
> largest object found in our Solar System since the discovery of Neptune
> in 1846.
>
> --------------------------------------------------------------
> PLANETS MNEMONICS
> My Very Excellent Mother Just Sent Us Nine Pizzas
> My Very Earnest Mother Just Served Us Nine Pickles
> Matilda Visits Every Monday, Just Stays Until Noon, Period
> --------------------------------------------------------------
>
> And it is thought to be larger than Pluto, whose status as the furthest
> planet from the Sun has been enshrined in accepted thought since it was
> identified in 1930.
>
> But this could all change.
>
> Technological advances have enabled astronomers to find more minor
> planets, stars, asteroids and comets.
>
> And in the late 1960s scientists found that Pluto's size had been
> over-estimated.
>
> It was first thought to be around as large as Earth, whereas accepted
> thought now suggests that the planet's mass is only around a fifth of
> the moon's.
>
> "Today, the world knows that Pluto is not unique. There are other
> Plutos, just farther out in the Solar System where they are a little
> harder to find," says David Rabinowitz of Yale University, who was among
> the astronomers who discovered 2003 UB313 two years ago.
>
> His point is echoed by Professor Mark Bailey, director of Armagh
> Observatory in Northern Ireland.
>
> "Increasingly, objects are far away and there are objects which are of
> comparable size to Pluto, so if you think of Pluto as a planet then you
> should refer to those objects as planets," he says.
>
> He estimates that there could be tens of thousands of objects beyond
> Neptune in the Solar System region known as the Kuiper belt, many of
> which may be larger than Pluto.
>
> The discovery of 2003 UB313 comes soon after it was announced that 2003
> EL61 had been found.
>
> And a number of distant objects around the same size of Pluto have been
> found in recent years, including Quaoar (found in 2002) and Sedna
> (detected in 2004).
>
> It is widely accepted that the struggle to provide an adequate
> definition of a planet is the crux of the problem.
>
> "Originally a planet was a wandering star. Then it was something that
> moved across the sky. Then it was something that revolved around the
> Sun. The criterion about when it should be called a planet is something
> that is changing over time," says Prof Bailey.
>
> "I'm sure we will continue to discover more and more objects of
> comparable size which will continue to challenge established thought
> about planets."
>
> 'Size does matter'
>
> Dr Brian Marsden, director of the International Astronomy Union's minor
> planet centre, believes the simplest way to resolve the confusion is to
> reject Pluto's claim to being a planet on the grounds that "size does
> matter".
>
> Instead he says people should accept that "we have eight planets and
> only an object bigger than Mars could be considered to be a planet in
> the future".
>
> He argues that the disruption that would be caused to accepted thought
> would, ultimately, provide a more accurate understanding of space.
>
> "School text books concentrate too much on the idea that Pluto is the
> ninth planet. Teaching should stress that there are hundreds of
> thousands of much smaller objects. Knowing a mnemonic and naming the
> planets is not science."
>
> But not everyone believes science has the right, or influence to turn
> accepted thought on its head.
>
> "Our culture has fully embraced the idea that Pluto is a planet and
> scientists have for the most part not yet realised that the term planet
> no longer belongs to them," says Michael Brown, one of the astronomers
> who discovered 2003 UB313.
>
> His conclusion is simple: "From now on, everyone should ignore the
> distracting debates of the scientists. Planets in our solar system
> should be defined not by some attempt at forcing a scientific definition
> on a thousands-of-years-old cultural term, but by simply embracing
> culture. Pluto is a planet because culture says it is.
>
> "It is understandably hard for scientists to let go of a word that they
> think they use scientifically, but they need to."
>
> He considers 2003 UB313 to be a planet in a "cultural" and "historical"
> sense, adding: "I will not argue that it is a scientific planet because
> there is no good scientific definition which fits our solar system and
> our culture and I have decided to let culture win this one.
>
> "We scientists can continue our debates, but I hope we are generally
> ignored."
>
>
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