It's not just Pluto's size. All the planets orbit the sun along roughly the same plane and in eliptical orbits. Pluto's orbit is not even remotely similar to any of the planets. To call pluto a planet you might as well call the moon a planet. Or any asteroid locked in an orbit round the sun. It's a big hung of rock, that probably belongs to the same group as UB313 in that it is in the Kuiper Belt.

So no, Pluto ain't a planet. It is an ancient Roman god, a cartoon dog, and an 'Icy Dwarf'. But not a planet.

Is it wrong that the only thing that went through my mind reading this was the pool scene in Red Dwarf

"Intended! Pool God! King of the Cues! Prince of the Planet-Potters!"


White Hole - Best. Episode. Ever!!

It's never wrong to thing about Red Dwarf (though maybe the last two series) and especially so White Hole, which was clearly inspired by my own pool playing skills.

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by Jayjay
...you might as well call the moon a planet ... orbit round the sun...

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The moon is not in orbit around the Sun, it's in orbit around the Earth

Surely orbital path is irrelevant in this particular debate, unless we're saying that there are no planets outside of our solar system? If we come across another "planet" somewhere in the far reaches of space, would we deny it it's status as a planet because it's orbit didn't resemble that of Earth (and the other 7 definite planets in the solar system)?

As for whether Pluto should be classed a planet or not, I don't know. I used to be mad-keen on astronomy as a kid, but my knowledge is severely lacking now. But if it is "de-classified" I imagine there'll be a pretty big uproar. From the people who have to reprint all the Astronomy books (the Junior Encyclopaedia of Space for example ), from the teachers who've been teaching wrong information all these years, and from the random sad geeks who just really like Pluto for some reason and want it to stay as a planet. (I'm in that last group... )

As for a tenth planet, we already have one don't we? It's called Rupert. (diverging from Red Dwarf slightly there... )

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by PictureOfFlowers

As for a tenth planet, we already have one don't we? It's called Rupert. (diverging from Red Dwarf slightly there... )

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http://www.tangent21.com/it.php?topic_id=7302

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by Vinnie
(quotes)


The moon is not in orbit around the Sun, it's in orbit around the Earth

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actually, the moon IS in orbit around the sun - its known as an "eccentric" orbit.
and theres hardly any chance of the IAU deciding to declassify pluto - theres far too many americans in the IAU, and guess which was the only planet discovered by an american??

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by mad
Theres far too many americans in the IAU, and guess which was the only planet discovered by an american??

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Very sad but true.

It was settled today that Pluto is a planet and so are three others including Rupert

Pluto survives as solar system acquires three more planets

Thanks for the reply on the moon's eccentric orbit round the sun, mad, that was the point I was trying to make. Flowers, a planet doesn't have to orbit our sun, but it should be in a regular orbit around a star. Otherwise it's just a smegging great big rock travelling through space. Like Pluto for instance.

Good point also on who discovered Pluto. Still, these are meant to be scientists, and Pluto clearly doesn't fit the category of planet. Who discovered it and issues with updating books shouldn't come into it. All that should matter is the science.

Besides, they could always make the new classification Planetesque, and the Americans would have been the first to discover one, and the books could just drop an errata slip in...

Just seen your update Gerri, and went over to the BBC website to see the full details...

Plutons! That's even worse than Planetesque! So now any big-bottomed asteroid caught in an orbit round a star, how ever distant, what ever the form of the orbit, is a planet. By the definitions reported by the BBC, Luna and all the other moons must also be considered planets. It's just silly. There is no scientific basis for classifying big asteroids with the eight 'classic' planets.

Daftest thing I've heard since I last listened to a member of our government...

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by Jayjay
Flowers, a planet doesn't have to orbit our sun, but it should be in a regular orbit around a star. Otherwise it's just a smegging great big rock travelling through space. Like Pluto for instance.

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Maybe I'm missing something here, as I said my astronomical knowledge is severely lacking. As far as I was aware Pluto does orbit the sun. It orbits it at an angle compared with the rest of the planets, and it gets closer to the sun at one end of it's orbit than at the other, but surely it's still an orbit? Are these the factors that make it an irregular orbit or am I missing something out? Mercury's orbit shows both of these factors too, though to a lesser degree, so why pick on Pluto?

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by mad
(quotes)

...and theres hardly any chance of the IAU deciding to declassify pluto - theres far too many americans in the IAU, and guess which was the only planet discovered by an american??

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That's a bit silly. Pluto stays a planet because an American discovered it. My goodness...

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by Sandia
That's a bit silly. Pluto stays a planet because an American discovered it. My goodness...

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Actually not so silly at all as it's scientific pride, politics and the human inability to admit their own mistakes. As top ranking members of the American astronomical organization what would you be more likely to do after you and your organization has spent years (if not your entire life) and millions of dollars on researching the planet Pluto:
1: Insist that pluto is a planet and therefore push for a change in the definition of "what is a planet". Which as positive side effect would have your organization (and collegues) would also be credited for the discovery of even more "planets". or
2: Vote for a stricter application of the "what is a planet" definition, stripping all the objects discovered in our solar system discovered by a member of the society you represent from it's title or planet and effectively admitting that you (and your organization) were wrong for 76 years, and you didn't do your work diligently enough.

Luckily is the new definition not yet final as they still have to vote about it next week as if this one passes we might get another 3 - 15 "planets"!

It's totally silly. To say that American scientists would go to this meeting and make this scientific determination based on some sort of misplaced nationalism or personal pride is ridiculous. It insults the scientific integrity of every astronomer, astrophysicist, planetary scientist, and so on, who is American. It's just beyond ludicrous.

Pluto was declared a planet--mistakenly, I believe--because when it was discovered we didn't know as much about it as we do now. It didn't stay a planet because Americans discovered it or had some bizarre obsession with keeping it one because they didn't want to admit Clyde Tombaugh (or whatever his name was)made a mistake. They had no idea decades ago that it WAS a mistake. It stayed a planet because we didn't know enough about it to say definitively that it wasn't one. As we have studied Pluto more extensively, with increasingly sophisticated equipment, we have became increasingly aware of its peculiarities.

Spending millions of dollars studying Pluto--in the United States and elsewhere around the world--wasn't a waste of money. It's scientific inquiry and discovery. It's how we know enough about Pluto now--and about the Kuiper Belt, the Oort Cloud, and planets beyond our solar system--to challenge Pluto's status as a planet.

Just FYI, the fact that Pluto may not be a planet isn't news that has just been uncovered in the United States. It has been a debate in the public domain at least since the 1990s. There's a very good article (a few years old)--on the evolution of Pluto's status and the way it has been thought of--by Neil deGrasse Tyson, an astrophysicist who is now the head of the Hayden Planetarium in New York City. This is the URL if you're interested in reading it.

research.amnh.org/~tyson/essays/PlutosHonor.html

I remember going to the Hayden Planetarium a few years ago, and I was surprised that the astronomical exhibits did call Pluto's status as a planet into question. They had already initiated a change in their thinking. Whether Pluto remains a planet or Pluto gets "demoted" to just another object from the Kuiper Belt, will be based on the scientific evidence that the group of scientists bring to the table, not on a bunch of American scientists who throw all scientific evdience to the wind and vote based only on the fact that some American decades ago looked through his telscope and just happened to see this chunk of rock and ice before anyone else did. Yeah, it's silly.

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by Sandia
Whether Pluto remains a planet or Pluto gets "demoted" to just another object from the Kuiper Belt, will be based on the scientific evidence that the group of scientists bring to the table, not on a bunch of American scientists who throw all scientific evdience to the wind and vote based only on the fact that some American decades ago looked through his telscope and just happened to see this chunk of rock and ice before anyone else did. Yeah, it's silly.

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Nobody said anything about throwing scientific evidence in the wind as yeah that would be silly. Scientific evidence is however open for interpretation, watching objects millions of miles from Earth is hardly an exact science. So there are many scientists who don't see Pluto as a planet as it doesn't fit the bill in the classical planet sense, which is a valid scientific reason.

However the classic definition of planet only has a fixed maximum weight no minimum one (as something isn't a planet if it's heavy enough to have internal nuclear fusion). Which gives other scientists a valid reason to say: "see pluto is a planet as it orbits a star".

The definition of what will now become a planet is create by a committee and I don't know if you are aware of the statement: A camel is a horse designed by committee.... Well they did come out with a monster of a definition which could even raise the total of planets to well over 50 with all the "round" objects in the Kuiper Belt.

If there are valid scientific arguments on both sides of the line the only thing that you have left to make a decision on are scientific pride, politics and general human nature as both sides of the argument feel they are right.

There is saying that in science that the right answer will also be the most elegant one.... I don't see how adding another 3 - 50 "planets" to the list is an elegant solution.

(Edited by Chambler 17/08/2006 15:36)

Flowers, was going to post a link to a site that summarizes why Pluto is not a planet, but to be honest, Sandia's link is better, not very long and very readable. Recommend that anyone with a passing interest reads it. Basically, it's the only planet that would melt into a puddle if it got too close to the sun. It is the only planet with an orbit that at times moves closer to the sun than other outer planets, before moving back out to being the furthest away: All the other orbits form concentric ellipses around the sun. The other planets were formed together at the birth of the solar system. Pluto is an icy rock that just happens to be trapped by the Sun's gravitational pull. It is no more a planet than the asteroids between Mars and Jupiter, the icy bodies in the Kuiper belt (like UB313 and Pluto itself), or Haley's Comet.

It's quirky, it's kinda cool. But a planet it ain't.

Sandia, thanks for the link. I don't think the concerns expressed here are an anti-American one (if that's the impression you got, and I could see why). More misanthropic than anything. Personally, if Pluto had been discovered by a Brit, was the only planet discovered by a Brit, and its finder had died less than 10 years ago, then I'd not be surprised to find the BAA defending Pluto's planet status despite the glaring anomalies. Basically, Astronomers, like all scientists, are humans first and logical, objective scientists last. And are as susceptible to pride as anyone else. There really is very little in the way of a scientific argument to classify Pluto (or Ceres, or Charon, or UB313 or the other trillion new 'Plutons') as a planet. It's inelegant, and that's a sure sign of a scientific theory being fundamentally flawed. Yet the vote amongst the IAU chairman for this new, ridiculous, classification of planet was unanimous. There has to be motives here other than science.

I mean, Plutons! What *****************...**********..* came up with that tosh!

Thanks for your post, Jayjay. As usual, intelligent and well-reasoned. I do see your point about the way nationalism could get in the way. It was just that, here I was reading arguments about whether or not Pluto should be a planet, and then there is this comment stuck in there saying that any Americans on the panel would vote based on some misplaced nationalism. I reacted to it because I just thought it was unnecessary.

That said, I do agree that the solution they came up with is bizarre, and probably creates more problems than it solves. Pluton? And I also have to agree that there had to be something working here other than scientific reasoning to come up with that. They obviously didn't want to say Pluto isn't a planet, because "Pluto the planet" obviously has a constituency. I need to read more about it to find out why they decided to keep Pluto a planet. I have read some quotes from Neil deGrasse Tyson, the author of the article I linked to, saying that he did not agree with the decision. I've read quotes from other astronomers here in the U.S. who also said, to use your words, it was "tosh." I guess the fallout isn't over. And, if I'm not mistaken, the entire group still has to vote on it this week.

Bloody hell, it appears you can't even count on the planets these days!

Interesting debate. I find myself coming down in favour of de-planeting the oversize snowball. This idea of "plutoids" or whatever they're calling them is going to make astronomy lessons impossible (although they'll probably be replaced with "advanced citizenship double-plus" classes before long, if they haven't already).

Failing that, the proposal to de-planet the earth would do wonders for the human ego.