# Twelve Planet Solar System



## Persephone (Aug 20, 2006)

I know this has nothing to do with Tolkien, but I just can't help posting it here.

There are other planets beyond pluto that have been discovered lately (Pluto being reinstated as a Planet, goodshow!  ), and according to BBC, there are more planets to come.

So, perhaps very soon we will hear children in schools reciting the planets of the solar system, as follows:

Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon, and UB313.


You can see the report here
*http://news.bbc.co.uk/1/hi/sci/tech/4795755.stm*


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## HLGStrider (Aug 21, 2006)

We need a real name for UB313. I am thinking of campaigning for Vulcan. It's a Roman god so it fits the requirements, plus think of all those happy Trekkies. 

Other possible names: Juno, Bacchus, Pan, Janus, Apollo . . . or we could leave behind the Greek, Roman thing and go with Norse or Native American or Hindu or something . . .Just so long as I can still spell and pronounce it. 

Personally, I'd also back Juno. It's a good strong name and it is a shame to have Jupiter but not Juno. Though it is a small planet.

Oooh, oooh, what about Minerva?


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## Talierin (Aug 21, 2006)

Minerva and Juno are I believe already used for some of Jupiter and Saturn's moons. And I believe the name they're going with is Xena.

Anyways, the proposel hasn't been passed by the IAU yet, some news places are reporting that it has been, but they don't vote on it till the 26th


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## HLGStrider (Aug 21, 2006)

Obviously astronomy isn't a big hobby of mine.

Anyway, I'd heard that they had "nicknamed" it Xena but this would change because it didn't quite follow the mold of other planet names (Ie comic book characters aren't on the same level as Roman dieties with the scientific community). I really would prefer they change it.


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## Persephone (Aug 21, 2006)

I hope they don't use Xena. Nothing against her fans, but whenever I think of Lucy Lawless I remember that one event where she accidentally shows her bumpers to a huge crowd.


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## Barliman Butterbur (Aug 21, 2006)

Narya said:


> I know this has nothing to do with Tolkien, but I just can't help posting it here.
> 
> There are other planets beyond pluto that have been discovered lately (Pluto being reinstated as a Planet, goodshow!  ), and according to BBC, there are more planets to come.
> 
> ...



When I was a kid, "planet" was defined as a solid (rather than gaseous [with the exception of the gas giants] or flaming) heavenly body in permanent orbit around a star. What's changed since? What's the big hoo ha?

Barley


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## Ermundo (Aug 22, 2006)

Barliman Butterbur said:


> When I was a kid, "planet" was defined as a solid (rather than gaseous or flaming) heavenly body in permanent orbit around a star.
> Barley



There is, nor was, a concrete definition for a planet so your definition was problably more of an assumption.


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## Barliman Butterbur (Aug 22, 2006)

morgoththe1 said:


> There is, nor was, a concrete definition for a planet so your definition was problably more of an assumption.



From the *Oxford Dictionary,* 2nd Ed.:

*Dictionary*

planet |planit| noun* a celestial body moving in an elliptical orbit around a star.* 
• (the planet) the earth : no generation has the right to pollute the planet. 
• chiefly Astrology, historical | a celestial body distinguished from the fixed stars by having an apparent motion of its own (including the moon and sun), esp. with reference to its supposed influence on people and events. The nine planets of the solar system are either gas giants — Jupiter, Saturn, Uranus, and Neptune — or smaller rocky bodies— Mercury, Venus, Earth, Mars, and Pluto. The minor planets, or asteroids, orbit mainly between the orbits of Mars and Jupiter. DERIVATIVES | planetology | noun ORIGIN: Middle English : from Old French planete, from late Latin planeta, planetes, from Greek planet ‘wanderer, planet,’ from planan ‘wander.’

*Thesaurus* 

planet | noun | which planets are visible to the naked eye | celestial body, heavenly body, satellite, moon, earth, asteroid, planetoid; literary orb.

===============================

Hey — this definition's good enough for the Oxford people, so it's plenty good enough for me — so until something earth-shattering happens (no pun intended  ), I'll stick with it.

And, you still haven't answered my questions: What's changed, what's the big hoo ha?

Barley


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## Ermundo (Aug 22, 2006)

Barliman Butterbur said:


> From the Oxford Dictionary, 2nd Ed.:
> 
> *Dictionary*
> 
> planet |planit| noun* a celestial body moving in an elliptical orbit around a star.*


A celestial object, that could mean any asteroid, comet, gas cloud, anything that can move in an elliptical orbit. 

Perhaps I was not in my right mind, but there is no *formal *definition for a planet. The oxford dictionary is simply to generic for my taste. And anyway, if a planet were categorized by such a definition, than there wouldn't be such a hassle for astronomers, amatuer or not, to decide whether a sattelite (spelled right?) should become a planet.


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## HLGStrider (Aug 22, 2006)

I think at issue is that some astroroids match that discription as well as about a hundred plus Kuiper belt objects, which is why Ceres had been listed as a planet at one time. Plus the scientific community was never happy with any of the definition, from what I've been reading. There had been some talk of discrediting Pluto as a planet because of its size or lack thereof for sometime.


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## Barliman Butterbur (Aug 22, 2006)

morgoththe1 said:


> A celestial object, that could mean any asteroid, comet, gas cloud, anything that can move in an elliptical orbit.
> 
> ...The oxford dictionary is simply too generic for my taste.



Well, _whatever_ these things are circling the sun, they are what they are _despite_ Man's problems with defining them. (As William James said, Truth is independent of human thought.) _They_ won't change; Man must keep on fine-tuning his science: thankfully, a never-ending situation. Truth is just at the horizon... 

Barley


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## Ermundo (Aug 22, 2006)

We all have issues than. Man it seems, has more than most, specially when it comes to naming things.



Barliman Butterbur said:


> they are what they are despite Man's problems with defining them.



Yes, but that won't change the fact that man DOES try to categorize them in a logical way. And in that, it seems that they're simply stuck like a piece of fish caught in a net.


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## Uminya (Aug 24, 2006)

Pluto has lost its status as a planet, as a panel 2,500 astronomers in the IAU has voted to redefine the term.

http://news.bbc.co.uk/2/hi/in_depth/5282440.stm

I agree with the decision. Science is not a place for sentimentality. Just as pennies should be removed from the US monetary system, so also should Pluto.

BBC has a good explaination of the whole thing.

http://news.bbc.co.uk/2/hi/science/nature/4798205.stm


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## Barliman Butterbur (Aug 24, 2006)

Ciryaher said:


> Pluto has lost its status as a planet, as a panel 2,500 astronomers in the IAU has voted to redefine the term.
> 
> http://news.bbc.co.uk/2/hi/in_depth/5282440.stm
> 
> ...



Thanks, Cir, for pointing us to those excellent pieces, part of which I quote here:

===============================

*So what definition have they decided on?*

For a celestial object to be considered a planet, it must satisfy two conditions:

The object must be in orbit around a star, but must not itself be a star
It must have enough mass for the body's own gravity to pull it into a nearly spherical shape.

Any object with a mass greater than 0.6% that of our Moon and a diameter greater than 800km would normally meet the second condition. But borderline cases will have to be resolved by more observation.

Some objects currently considered to be moons and asteroids could be eligible if they meet those basic tests. So the definition leaves the door open for other objects to join the expanding club.

*So was Pluto downgraded or not?*

In one sense, Pluto has been demoted. This world has always been the odd one out; it has less than one four-hundredth the mass of Earth and has a tilted, elliptical orbit around the Sun.

The IAU's draft proposal recognises eight "classical" planets - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune - three "plutons" - Pluto, Charon and UB313 - and the asteroid Ceres.

Many astronomers think Pluto is part of a vast population of icy objects that orbit the Sun beyond Neptune, in a region called the Kuiper Belt. These objects have a different origin from planets like Earth and Jupiter; they are thought to be leftover debris from the formation of the Solar System.

The new category of plutons distinguishes Pluto and other "icy dwarfs" from classical planets in that they reside in orbits around the Sun that take longer than 200 years to complete, circle the Sun with high "inclination" (are highly tilted with respect to the classical planets) and typically have orbits that are far from being perfectly circular.

But the plutons fit all the criteria of the new definition of a planet, so Pluto does not receive the full demotion some astronomers had hoped for.

===============================

Let us not forget something here: Despite humankind's wrestling with this "problem," it's still nothing but an ultimately _human_ classification system. All these objects will go on being exactly what they are and what they have always been, totally independent of what those little creatures on that small planet third from the sun happen to call them, despite all the hoo ha and reclassifying that astronomers may decide upon.

I am reminded of a Sufi story (and I wish I could remember the whole thing correctly): A trail of ants was wandering over a vast white plain, when suddenly they saw a gigantic pink and gold monster trailing rivers of black blood. This had them quite agitated until they came up with an explanation which satisfied them, and also which, unbeknownst to them, was completely wrong. What they really saw was a hand holding a fountain pen writing a letter. Ants being ants, they could not come even _slightly_ close to apprehending any of that.

And a 19th century story from Judaism: A crowd of Jewish men were new in Moscow, and there were sights they had never seen, one of which was an electric trolleycar. They considered this a miracle — until their rabbi made a totally logical — and entirely incorrect — explanation. But the men were satisfied: "Ah, _now_ we understand!" But they _didn't_ understand, they only _thought_ they did, because the explanation made logical sense to them. 

My point: people want things to make sense. And when they get an explanation that _makes sense *no matter how far-fetched*_ never mind whether it's _correct_ or not — then they relax, then they feel satisfied. This occurs in all levels of human discourse and commerce, anything you can name. It's a fundamental part of how our thought process operates. And it's a part of what always has us in so much trouble.

Barley


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## DGoeij (Aug 24, 2006)

Barliman Butterbur said:


> My point: people want things to make sense. And when they get an explanation that _makes sense *no matter how far-fetched*_ never mind whether it's _correct_ or not — then they relax, then they feel satisfied. This occurs in all levels of human discourse and commerce, anything you can name. It's a fundamental part of how our thought process operates. And it's a part of what always has us in so much trouble.
> 
> Barley



Funny. Have you been reading those books by 'discworld' author Terry Pratchett and two scientists? The first is about how todays science explains the rise of our solar system and earth itself. In the second book they do the same for the evolution of mankind and they classify humans as the Pan Narrativium (the storytelling ape). Partly because of our tedency to make stories (lies to children as they call them) to understand our surroundings as you so funnily describe.

You are absolutely right as well. I don't think the relatively small rock (although I do not wish to bump into it) we call Pluto is very impressed. But I do agree it has some importance for us and I'm glad that the people that consider themselves scientists, try to classify things by logic, not by sentiment. It does have its merits, but not when you try to communicate about the solar system, IMHO.


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## chrysophalax (Aug 24, 2006)

Publishers of school science books all over the world are seeing $$, I'm sure!


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## Alcuin (Aug 24, 2006)

Funny. I’ve been alive for a while now, and when I woke up this morning, the universe didn’t feel any different to me. 

Do you think it would make any difference if astronomers decided to call Pluto a “planet” or a “dwarf planet” or a “fsxyazz”? Does it matter to Pluto? Was it there before Clyde Tombaugh discovered it in 1930? Will it still be there when mankind is no more? Did its orbit or its composition or its mass or its reflectivity change at all? Come to think of it, isn’t Pluto too small to account for the perturbations in the orbit of Neptune that led the Lowell Observatory to search for a planet in that region of space in the first place? (“Holy astrophysics, Batman! There’s still a great big undiscovered ‘planet’ out there someplace!”)

Oh, yeah, and how many elementary school teachers will continue to teach kids that the next solar system object outside Neptune’s orbit is called “Pluto”? and how many of them will continue to teach those bright little minds that “Pluto” is really a “planet,” regardless of what the IAU says?


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## Barliman Butterbur (Aug 24, 2006)

Alcuin said:


> Funny. I’ve been alive for a while now, and when I woke up this morning, the universe didn’t feel any different to me.
> 
> Do you think it would make any difference if astronomers decided to call Pluto a “planet” or a “dwarf planet” or a “fsxyazz”? Does it matter to Pluto? Was it there before Clyde Tombaugh discovered it in 1930? Will it still be there when mankind is no more? ...



Yup yup yup, you got it! As William James famously said, "truth" is quite independent of what Man happens to think of it at any given moment. 

And no, I've never read any of the Discworld books. The idea that we are constantly slapping Labels on Things, and then slapping on New Labels when we come to understand more about them is simply a conclusion I've come to by general observation, reading and chewing things over, over the course of a reasonably long life. Our knowledge is always a shifting and a becoming, never a final arrival — like trying to catch up with the horizon.

Barley


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## Persephone (Aug 24, 2006)

Alcuin said:


> (“Holy astrophysics, Batman! There’s still a great big undiscovered ‘planet’ out there someplace!”)


 

lol!!! I would never have thought of this!

Well, I thought they took back that "Pluto is not a planet" statement and keeping the old idea that it is? Now, I'm confused.


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## Alcuin (Aug 25, 2006)

Narya said:


> Well, I thought they took back that "Pluto is not a planet" statement and keeping the old idea that it is? Now, I'm confused.


Here’s a good synopsis from Space.com. Pluto is now officially a “dwarf planet.” 

The argument began not over Pluto, but over what are called Kuiper Belt Objects (KBOs), of which Pluto was the first to be discovered. They are apparently rather numerous, and some of them appear to be quite large, larger even than Pluto, which itself is not as big as our Moon. So there was an argument over whether or not newly discovered KBOs should be counted as planets, too. (Astronomers are finding them rather quickly with new telescopes.) The upshot was that while most folks were comfortable with the idea that Pluto was a planet, not everyone was comfortable that all these KBOs should be considered planets, and defining them down meant that Pluto had to go, too. So the astronomers who wanted to keep counting Pluto came up with a definition that basically said, “If it’s round, it’s a planet.” But that counted 12 planets, including Ceres, which has always been considered the largest of the inner solar system asteroids; and in addition, there are about 40 moons, including our Moon, Saturn’s Titan, and at least Jupiter’s 4 largest moons, that would either also become planets or would be larger than some of the planets. So, back to the drawing board they went, and the astronomers came up with the idea of “dwarf planets” into which Pluto has now been classified.


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## Barliman Butterbur (Aug 25, 2006)

Alcuin said:


> ...the astronomers who wanted to keep counting Pluto came up with a definition that basically said, “If it’s round, it’s a planet.”



Well, that's most of it but not all of it. It has to be in direct orbit around a star but not be a star, and it has to have enough mass so that its own gravity pulls it into a spherical shape. But is Pluto spherical, or does it look more like an asteroid? If it's spherical, it should qualify as a full-fledged planet by their new definition. *sigh*

Barley


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## Uminya (Aug 25, 2006)

Pluto has a spherical shape. I again restate that the best reasoning for Plutos non-planethood is the shape of its orbit. For one, it's not a near-circle as are all of the other planets. It's highly eccentric, like a comet's. Secondly, it's not quite level with the "solar plane" that all of the other planets are orbiting on.

Trying to attach metaphysical reasoning to astronomy doesn't work. No, it doesn't technically matter what you call a planet, or an asteroid, or whatever, because it is what it is. But you can't classify objects without a solid definition, which didn't exist until now, and with astronomy and astrocartography being the tremendous and terrifying complex things that they are, there's no choice but to develop solid systems for classifying objects now that we have the technology to actually know that they're there.

As I said. It's like pennies and states. People like pennies, because they're sentimental and pennies are something they're used to. People like flags with a nice, even 50 states. If Puerto Rico decided to become a state, you can imagine the hubbub there would be from all the items that would have to be redesigned to accomodate 51 stars. People are used to 9 planets, even though it has no bearing on their day-to-day affairs. They like their little MVEMJSUNP mnemonics, and loathe changing textbooks.

It's ok, though. People had a hard time grasping that the world was round and that the moon wasn't made of cheese and stars are big balls of fusing plasma hanging in a vast nothingness and not candles on a big black dome. They'll get over it.


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## Barliman Butterbur (Aug 25, 2006)

Ciryaher said:


> Pluto has a spherical shape. I again restate that the best reasoning for Plutos non-planethood is the shape of its orbit. For one, it's not a near-circle as are all of the other planets. It's highly eccentric, like a comet's. Secondly, it's not quite level with the "solar plane" that all of the other planets are orbiting on.



Ah, but as far as I understand it, the shape of the orbit wasn't mentioned in the new definition, only that it had to be a non-star spherical body in direct orbit (no mention of the type) around a star — but what do I know?



> It's like pennies and states. People like pennies, because they're sentimental and pennies are something they're used to.



Personally, I have absolutely no use for them (except as an occasional screwdriver when I need to open a battery well on some electronic doodad), and they go straight into my penny jar. When it fills (about every five years or so) I give the jar full of pennies to my daughter, a tradition almost 40 years old. On the other hand my wife carries a coin purse in her larger purse with every popular denomination of coin, and it adds another fifteen pounds or so to the whole deal. The last woman other than my darling beloved that I knew who carried a working coin purse was my grandmother.



> People like flags with a nice, even 50 states. If Puerto Rico decided to become a state, you can imagine the hubbub there would be from all the items that would have to be redesigned to accomodate 51 stars.



I thoroughly enjoy flags, and quite look forward to the hubbub accompanying a new star in the field! I hope the new configuration is a Peace Sign!  



> People are used to 9 planets, even though it has no bearing on their day-to-day affairs. They like their little MVEMJSUNP mnemonics, and loathe changing textbooks.



What is MVEMJSUNP?



> It's ok, though. People had a hard time grasping that the world was round and that the moon wasn't made of cheese and stars are big balls of fusing plasma hanging in a vast nothingness and not candles on a big black dome. They'll get over it.



Some still do, and some will not...  

Anyway, here's a vitally important article on the fallout from a Plutoless solar system:

AUGUST 24, 2006

TOP NEWS
By Douglas MacMillan

*A Solar System-Size Headache*

_Now that astronomers have booted Pluto from the ranks of official planets, what's a planetarium gift shop to do?_

It's not often that the solar system loses a whole planet, but it did just that on Aug. 24, when the International Astronomical Union (IAU), meeting in Prague, changed the definition of a planet to exclude Pluto, dropping the count of official planets from nine to eight. And while it was the scientific community that had to deal with the impact of the change in their view of the cosmos, some Earth-bound businesses began toting up the dollars-and-cents implications of Pluto's expulsion.

Affected by the move are stacks of school textbooks, diner place mats, bedroom posters, computer software, glow-in-the-dark mobiles, encyclopedias, and entire museum exhibits depicting the now-obsolete nine-planet solar system. But while it's clear that the change will mean significant replacement costs for businesses in the education industry, other pockets of space commerce are counting on the upsurge of interest in things planetary to generate new growth. 

At Chicago's Adler Planetarium & Astronomy Museum, the ongoing debate about the categorization of planets over the past few months has already sparked newfound interest in museum exhibits, sky shows, and an interactive classroom called CyberSpace—which is equipped to quickly reflect scientific advancements like these. "It's exciting for the general public," said Susan Wagner, Adler's vice-president for exhibits and programs. "We are here to educate, and we will be very happy to engage the visitors in this debate." 

In addition to altering its permanent exhibits, Adler will immediately incorporate the new definition of Pluto as a "dwarf planet" into its live planetarium shows and may soon begin an educational lecture series on the topic, according to Wagner.

Full story here

===============================

The story also covers the looming problems of updating encyclopedias and textbooks, and there is also an entertaining slideshow of products affected by Pluto's "demotion."

Personally, I would advise those affected by the change to hold off on any updates, at least for a while — there may be a rising tide of Pro-Pluto-ites out there shouting for reinstatement, and if they win, then there would be the double cost of downdating after updating — what a lot of tomfoolery! 

Barley


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## Persephone (Aug 25, 2006)

What is MVEMJSUNP?


I think that stands for *M*ercury, *V*enus, *E*arth, *M*ars, *J*upiter, *S*aturn, *U*ranus, *N*eptune and *P*luto.


The thing is we know very little about the Solar System to accept anything about it as concrete fact. We are just beginning to discover many things about the Universe and while we're at that stage of discovery, I don't think we should be afraid of change. It is the only constant thing anyway. What we know today may be challenged tomorrow and updated the following day.


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## Barliman Butterbur (Aug 27, 2006)

Narya said:


> What is MVEMJSUNP? — I think that stands for *M*ercury, *V*enus, *E*arth, *M*ars, *J*upiter, *S*aturn, *U*ranus, *N*eptune and *P*luto.


 
Aha! Well, now it's only MVEMJSUN...for now... 

BTW —I was talking to an avid amateur astronomer yesterday about the new definition of a planet, and he refined it slightly for me: A planet must be a not-star in direct orbit around a star, it must have enough mass so that it's own gravity pulls it into a spherical shape, AND its orbit must not interfere with any other planet's orbit. Hey, I don't make this stuff up!

Barley


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## DGoeij (Aug 27, 2006)

If I wasn't so preoccupied with myself as of late, I could have really enjoyed a conversation like this. 

I really sounds like something I could be doing with several of my friends, either around a campfire (boyscout sounds a bit silly when you're 26, but that's what I am) or in a bar somewhere.

But I thought this UB21something was going to be a planet as well, or did it qualify as dwarf-planet in the end?

I could look it up myself, but that's no fun at all, now is it?


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## Barliman Butterbur (Sep 4, 2006)

*(It ain't over till it's over!)*

*The Fight for Pluto Rages On*

September 1, 2006
by the Editors of Sky & Telescope

It's not over yet.

In the past week a small but growing group of scientists made their first formal attack against the International Astronomical Union's August 24th resolution that left the solar system with eight planets and downgraded Pluto to a new class of objects known as "dwarf planets."

On Thursday two heavy hitters in the planetary-science community — Mark Sykes, director of the Planetary Science Institute, and S. Alan Stern, an executive director of the Southwest Research Institute and leader of the Pluto-bound New Horizons mission — unveiled a petition formally disputing the new definition. The petition, signed by more than 300 of the world's leading space scientists, states, "We, as planetary scientists and astronomers, do not agree with the IAU's definition of a planet, nor will we use it."

The signatories call for a "better definition" of a planet and ask that the method to determine that definition includes more input from the global astronomical community. *According to the petitioners, only about 4% of the IAU's nearly 10,000 members were present in Prague to vote on the resolution.* In a prepared statement Sykes wrote, "A more open process, involving a broader cross section of the community engaged in planetary studies of our own solar system and others, should be undertaken."

Says Stern, "From the number of signatories that the petition received in a few days, it’s clear that *there is significant unhappiness among scientists with the IAU’s planet definition and that it will not be universally adopted by scientists and textbook writers."*

Other battle lines are being drawn as *some scientists are questioning the IAU's authority in this matter altogether.* The director of the Center for Space Exploration Policy Research, Mark Bullock, released the following statement: *"A key public-policy question is who has the social mandate to alter the definition of something as fundamental as a planet.* Scientists have in the past vested the IAU with authority to name asteroids and other planetary objects. However, *the word 'planet' has cultural, historical, and social meaning and as such requires much broader discussion and consensus than those required for the naming of astronomical bodies."*

Meanwhile the chair of the American Astronomical Society's Division for Planetary Sciences, Richard G. French (Wellesley College), urged the group's more than 1,200 members to recognize the authority of the IAU to render their decision and reiterated that refinements to the definition are desired. In a letter to the DPS community, he writes, "There is still work to be done, too, in constructing a definition that is generally applicable to extra-solar planetary systems. These and other changes, radical or moderate, presumably will be addressed at the next IAU General Assembly in Rio de Janeiro in 2009, and the DPS community will continue to be involved in all stages of this process."

You can read the Sykes-Stern petition, including the list of signatories, at http://www.ipetitions.com/petition/planetprotest.

Source: http://skytonight.com/news/home/3805531.html

===============================

I recommend you click on the list of signatories above. You'll find that it is not just a gaggle of yammering fringe loonies, but an international list of several hundred serious and accomplished astronomers, representing major planetaria and university astronomy departments in the U.S. and around the world, as well as NASA and JPL.

Barley


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## Shireman D (Oct 12, 2006)

Well, I know what a UB40 is but UB313 is a new one on me.

Mind you, none of the folk in this conversation who are without the borders of this shire will understand the UB40 remark (unless they happen to listen to old Bangles songs).

To my way of thinking it's all quite clear - if Gustav Holst wrote a tune for it, it's a planet, if he didn't it ain't.

Garruumph.


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