IAU Demotes Pluto to 'Dwarf Planet' Status 426
davidwr writes "It's official. Pluto's been demoted. It's now one of several 'dwarf planets.' I guess we can drop the 'Period' from 'Mary's violet eyes make John stay up nights.'" (Of course, no one says you have to privately agree with the International Astronomical Union.) Several readers have contributed links to the BBC's coverage of the downgrade, as well as the usefully illustrated story at MSNBC.
my take on it: (Score:5, Funny)
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Re:my take on it: (Score:5, Funny)
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Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
And, did anyone ever really think of Pluto as a planet?! At best, it's a comet that doesn't enter the inner solar system.
Re:my take on it: (Score:5, Funny)
What's he going to do now?
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I agree...screw Neptune.
Mnemonic to remember planets (Score:2)
To this day, I have Interplanet Janet playing in my head when I think of the solar system.
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...the IAU has been demoted to just a bunch of geeks with nothing better to do than reclassify frozen rocks.
...Earth astronomers destroy any chance of interplanetary relations with Uranus.
...Walt Disney may be rolling over in his grave, but Pluto discoverer Clyde Tombaugh is surely spinning!
And... Congratulations IAU, thanks to you, anyone with born under the Astrological sign Scorpio now has no ruling planet.
Re:my take on it: (Score:5, Funny)
At a rate of once every six days, nine hours, seventeen minutes, and thirty six seconds.
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Clyde Tombaugh is surely spinning!
In astronomy, they don't call it spinning, but "ro...tat...ing" (making finger quotes as I type). You have to give some respect to the man who discovered the biggest snowball that side of the asteroid belt
Re:my take on it: (Score:5, Informative)
I wouldn't call it a screw-up.
The draft proposal was:
Pluto would continue to be a planet, and Ceres, Charon and 2003 UB313 would become planets. However, this criterium is reached by hundreds, even thousands of other celestial bodies in our solar system. Under that proposal, all could gain planet status.
The final text is:
This definition does not define the terms "nearly round", nor "neighbourhood". But having a definition, rather than just an enumeration, is in my opinion a big leap forward. Demoting Pluto is a small price to pay.
I quite like the additional criterion of dominance of a body in its neighbourhood. It's not as arbitrary as simply requiring a minimum mass or size.
On the other hand, I do not like the fact that a planet should orbit to Sun to be called a planet. On this point, I preferred the original proposal in orbit around a star. I don't see why our solar system should be any different, why planet-like celestial bodies orbitting other stars are not called planets.
Re:my take on it: (Score:5, Interesting)
Pluto orbits the sun, but it also orbits a point in space above its surface. Charon doesn't orbit Pluto, but orbits a point in space above the surface of Pluto, while it too orbits the sun. Can someone explain to me why this shouldn't be called a double?
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Not that it really matters all that much. As other astronomers have commented, they mostly just say "body" and give a list of specs. Terms like "planet" are a bit too vague to be useful as technical terms. After all, Mercury
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.. but given enough time... (Score:3, Insightful)
But isn't the Moon's distance from Earth slowly increasing thus, surely, the binary planet definition will also apply to the Earth+Moon eventually?
Re:.. but given enough time... (Score:4, Informative)
Actually (if I did the math correctly) in about 3,529,037,195 years. That's still within the projected lifetime of the solar system, so yes
Re:my take on it: (Score:4, Interesting)
"is not a satellite" does not exclude Charon, because they picked a somewhat peculiar definition of "satelite" (barycenter of gravity inside the primary), which excludes almost everything we typically think of as a moon, but not Charon. This definition makes the Moon a satelite, but if the Earth had a slightly smaller radius but the same mass, the Moon would follow exactly the same orbital track, but suddenly be a planet.
I beleive they picked this definition of "satellite" specifically to exclude Earths Moon. If you actually plot the orbital tracks of the Moon, Charon, and any other moons you like, one stands out like a sore thumb as the one that should obviously be said to be orbiting the Sun. It's not Charon.
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They claimed to exclude Charon from being a dwarf planet, so they're obviously not using the barycenter definition to determine what a satellite is.
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Legal issues.
If we get off this rock, we will probably allow asteroid mining. It would then be OK to reduce an asteroid to rubble to extract the ore that you want. Now imagine Pluto has some valuable Ultra-rareium at its core. Is it OK for a company or a country to smash it to pieces?
These definitions are important so laws can be made. Is it OK to bury radioactive waste in an asteroid? What about Mars? Does this apply to all planets, or
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C+ - Very sloppy work
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Now about that definition - in my very naive view, shouldn't the definition of "planet" have something about the body in question orbiting in the plane of the star's equator? I think that would go a long way towards differentiating captured comets, asteroids, etc. from the "classically" formed planets.
Can someone explain why that doesn't make sense?
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> Sun to be called a planet. On this point, I preferred the original
> proposal in orbit around a star. I don't see why our solar system
> should be any different, why planet-like celestial bodies orbitting
> other stars are not called planets.
Because they're only defining what a Solar planet is, not the general meaning of the word "planet":
The IAU therefore resolves that planets
Mutually exclusive (Score:3, Funny)
Sorry, I should have said mutually exclusive set. Really wikipedia has a good diagram, but the orderly diagram makes it appear to be a logical distinction rather the linguistic mess that it is.
A: Pluto is a planet
B: No, Pluto is a dwarf Planet.
A: Yes, that's right I said it was a planet.
B: But it is a dwarf planet, so you are wrong.
A: Isn't a dwarf planet just a type of planet?
B: No.
A: Then why is it called a planet at all
B: uhhh, cause
Ok, so no we have... (Score:2)
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8 Planets and 8 Dwarfs? Sounds simple enough...
That's Size Challenged Planets
Thank you very much...
Re:Ok, so no we have... (Score:4, Funny)
Mnemonic device update (Score:5, Funny)
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Now every geek's question is... (Score:5, Funny)
Re:Now every geek's question is... (Score:5, Funny)
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Information Correction (Score:2)
Astrologers panic! (Score:5, Insightful)
So will this render all astrological predictions which took Pluto into account as invalid? I'm sure the kooks will come up with some excuse to explain how their previous charts were accurate at seeing the future as if they ~knew~ this all along.
Re:Astrologers panic! (Score:5, Insightful)
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Then again, when you're dealing with flimflam you can pretty much say whatever you want.
The fact that NPR had this segment only served to legitimize this nonsense and continued to give hope to the gullible that astrology is valid.
A new one (Score:5, Funny)
Why is this "breaking news" (Score:4, Insightful)
Now that would be breaking news!
Re:Why is this "breaking news" (Score:5, Funny)
NJ: Come taste the rainbow... mmmm (Score:2)
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I'm not sure hitting New Jersey would be good, though. Could you divert it so it hits Texas, or New Orleans?
Pluto demoted? (Score:3, Funny)
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Freezer. He is turning over in his freezer.
That changes everything (Score:5, Funny)
Re:That changes everything (Score:5, Insightful)
Mnemonics (Score:2)
I still remember a great one from when the USSR blew up. I think it was a contest in Games magazine or something. Anyway, it goes Gorbachev's khaki underwear always tends to ride up at long lines exiting boring Kremlin meetings. Compare with http://en.wikipedia.org/wiki/Republics_of_the_Sov i et_Union [wikipedia.org]. Amaze your friends! Fool your enemies!
So why does Neptune qualify? (Score:5, Interesting)
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Pluto's response to the breaking news: "Damn you Neptune! This is all your fault! If I don't get to be a planet then I'm taking you down with me!"
Re:So why does Neptune qualify? (Score:5, Informative)
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http://www.google.com/search?q=pluto+neptune+reson ance [google.com]
http://en.wikipedia.org/wiki/3753_Cruithne [wikipedia.org]
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Re:So why does Neptune qualify? (Score:5, Informative)
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Son of a B*****!!! (Score:3, Funny)
Teaching about Pluto in School (Score:3, Interesting)
I got in similar trouble to telling my teacher that her solar system model was wrong because all of her planets were on the same plane. And, got in more trouble when I mentioned that Pluto is not the furthist planet from the sun, but rather Neptune was (at least, at that time). Of course, the worst was when I corrected a teacher whom said Saturn was the only plane
Stupid (Score:2, Insightful)
Create the new definition with a stipulation that for historical reasons, Earth's generally accepted planets will remain in the planet class. There's nothing wrong with that. It's not like any meaningful astronomy research is going to get confused.
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Besides, if Pluto wasn't discovered by Clyde Tombaugh at Lowell Observatory in Arizona (US), I don't think there would have been much strong objection to demote Pluto as a dwarf one.
Still it is a planet, I guess it's a compromise fro the pride.
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Ask the Creationists.
To stay on topic, now that Pluto is no longer an "official" planet, Jupiter should be next. It's a brown dwarf star after all, isn't it? Even the definition of is a little up in the air [wikipedia.org].
Re:Stupid (Score:5, Insightful)
Given the level of scientific illiteracy, what the hell is the point of taking something that everyone does know and declaring it to be wrong?
"Everyone" knew there were eight planets prior to 1930. Did the world end when it was changed to nine, especially with something that wasn't even obviously a planet?
Guess what? A whole generation of children will grow up with the new, consistent rules and won't know any different. What's unarguable is that the new rules are better. I'm all in favor of fixing things that are broken, even if certain curmudgeons are too mentally inflexible to make the adjustment. See also: the metric system in the US, which is kept down by the same curmudgeons.
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Not sure why the IAU gets to decide what a planet is. There seems to be useful no scientific distinction between a planet and a planetoid. Popular meaning should prevail.
Courtesy correction to terminology (Score:3, Funny)
Actually, "dwarf planet" is considered rude.
It prefers to be called a "little planet".
(And besides, if Pluto is going to be the dwarf planet, which planet do the elves get? Or the hobbits? Won't someone think of the hobbits?)
You mean (Score:2)
The demotion was due to this factor: (Score:2)
Napoleon... (Score:3, Funny)
I don't like this at all.
You IAU bastards! Now, My Very Educated Mother no longer Just Sat Under Napoleon's Picture. Now, My Very Educated Mother Just Sat Under Napoleon.
You guys are sick. Leave my mother out of this.
cool? (Score:2)
"Brown was pleased by the decision. He had argued that Pluto and similar bodies didnt deserve planet status, saying that would take the magic out of the solar system.
UB313 is the largest dwarf planet. Thats kind of cool, he said."
cool?
Holst was right. (Score:5, Funny)
Pluto needs out help ! (Score:2)
Oh yeah, and couple billion tons of mass as development aid wouldn't hurt, either.
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No. Erm, wait. Do they have oil ?
Methane ? Close enough.
Mary? (Score:2, Informative)
Andrew
why? (Score:2)
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From before Pluto was a planet (Score:2, Insightful)
Anyone? Anyone? (Score:4, Interesting)
Pluto is automatically disqualified because its oblong orbit overlaps with Neptune's.
1) - Is it possible for Pluto and Neptune to one day (like within the next couple billion years) collide? Or are their respective orbits degrading to the point where by the time they'd be near each other orbit-wise, their orbits would no longer overlap significantly? Or by 'overlap' do they mean "diagrammatically speaking, on a two-dimensional representation they overlap but even at their closest possible point they're still a squillion miles away from each other"?
2) - If so, how cool would that be? Would it be funny enough to make it onto an America's Funniest Home Videos video montage? Would it need special clown-horn-honking sound effects?
3) - Considering their distance from Earth and their relatively small size, would a collision of the two have any noticeable effect here on Earth?
4) - Seriously, how cool would worlds colliding be?! Costanza jokes aside, I think it'd be awesome to the max.
Re:Anyone? Anyone? (Score:4, Informative)
Is it possible for Pluto and Neptune to one day (like within the next couple billion years) collide?
Nope. Their orbits are in 3:2 orbital resonance [wikipedia.org]; basicly this means they constantly miss each other (a bit like your average commuter bus and train schedule :P). Also, due to the declination of the Pluto orbit it doesn't even touch the Neptune orbit. When seen straight from above, the orbits overlap, but if you go off-angle to just the right spot the Pluto orbit can be seen to be completely separated from Neptune.
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2. Yes, it would be interesting (maybe not funny, though)
3. It probably wouldn't have an
Nursery rhyme... (Score:2, Funny)
Eight little planets, orbiting around the Sun, one was deemed too big, and then there were seven...
Seven little planets, orbiting around the Sun, one had too many rings, and then there were six...
Six little planets, orbiting around the Sun, one got too close and melted, and then there were five...
Five little planets, orbiting around the Sun, one got too cold and froze, and then there were four...
Four little p
Amateur Night In Prague (Score:2, Interesting)
In programming terms, the function:
bool Is_Planet( Astronomical_Object* foo );
, does not yet exist. Well, under some proposals, it would have existed in the following form:
bool Is_Planet( Astron
Conspiracy (Score:2)
That's exactly what it would like us to think...
Piss on the IAU! (Score:2)
Beyond the fact that Clyde Tombaugh got eyestrain looking at photogrpahic plates trying to find the damned thing in the first place (he's doing 7200 RPM in his grave as we speak - people in Las Cruces can hear the high-pitched whine), the fact is we all grew up thinking of Pluto as a planet and this whole fracas has been nothing but a circus of uptight astronomers, lame-brained reporters, and fringe wackos.
I for one am not going to give in -- Pluto's a planet, case closed. When we go whippinng through oth
Well (Score:2)
So much for those Sports Night quotes (Score:2)
Pluto and Neptune (Score:3, Insightful)
Doesn't that mean that Neptune also hasn't cleared it's neighborhood? It's orbit overlaps that of Pluto. So why is IT a planet?
textbook makers rejoice... (Score:2)
does anyone know if this ruling applies in kentucky? given that whole "evolution is just a 'theory'" thing and all..
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Neptune has more than enough gravity to munch up anything in its vicinity that's not in an orbit.
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Maybe to someone simple-minded enough to think that words need to have clean cut definitions despite the fact that philosophers have demonstrated for at least a century that word meanings can form 'family resemblances' without there being a single point in common between them. And what is the problem with counting new objects as planets? We have a notion of 'planet'. We look through telescopes and see more of the same. Pe
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No facts of the matter have been found to be different. You do know this don't you? This is an argument over linguistics, not over science. Ancient Greeks (and others) realised that the world wasn't flat. This was an actual discovery about the world - not an argument about the meaning of the word 'fl
Schools slow to act (Score:2)
Twenty years will go by before schools teach this. Schools have to wait for some teachers to die off, posters to get reprinted, new books ordered, etc.
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Re:my take on it: (Score:4, Interesting)
I'm assuming for the moment that it was misreported. The real problem with Pluto is the thirteen other known Plutinos -- objects not gravitationally related to Pluto, but also in highly elliptical Neptune-cossing orbits with a 3:2 resonance to the Neptunian orbit.
Now, there are a bunch of objects which have stable solar orbits with a period the same as Mars. But in the case of Mars, they all either orbit Mars itself, Sol-Mars L4, or Sol-Mars L5. Same can be said for Jupiter, Saturn, Uranus, and Neptune (and Earth, except the "bunch", since Earth only really has the Moon).
Instead, Pluto is like Ceres, which has a number of objects in the same orbit which are all more-or-less doing their own thing. Demoting Pluto now that we know about the Plutinos is like the demotion of Ceres after the discovery of a bunch of other asteroids in the same orbit.
The problem is that the public wasn't right. (Score:3, Insightful)
No. We've known for decades that the "planet" Pluto was far smaller than any other planet and made of fundamentally different stuff. And through all that time, astronomers let it go because every time one of them mentioned that Pluto wasn't really a planet he was shouted down by the public. Now that we know there are dozens of bodies just like Pluto - and some even larger - what little scientific ac