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Pluto Making a Comeback
Posted by
CowboyNeal
on Thu Aug 31, 2006 11:46 PM
from the little-space-mass-that-could dept.
from the little-space-mass-that-could dept.
anthemaniac writes "Space.com reports that the American Astronomical Unions Division of Planetary Scientists recognizes the IAU's authority to make a new planet defintion but expects it to be altered. Separately, 300 astronomers have signed a petition saying they won't use the definition. All this stems from the discontent over how only 424 astronomers voted on the proposal that demoted Pluto. Looks like this little dog is on the comeback trail."
Related Stories
[+]
IAU Rules Pluto Still a Planet 244 comments
scottyscout writes "NPR reports that Pluto has dodged a bullet.
An international panel has unanimously recommended that Pluto retain its title as a planet,
and it may be joined by other undersized objects that revolve around the sun.
Some astronomers had lobbied for reclassifying Pluto as its so tiny. And at least one major
museum has excluded Pluto from its planetary display. But sources tell NPR that under the
proposal, to be presented at a big meeting of astronomers in Prague next week for a vote,
Pluto would become part of a new class of small planets and several more objects could be
granted membership."
[+]
IAU Demotes Pluto to 'Dwarf Planet' Status 424 comments
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.
[+]
Pluto Decision Meets with Frustration 464 comments
fuzzybunny writes "The BBC reports that the IAU's controversial Prague vote on demoting Pluto from planet status was irregular. 'There were 2,700 astronomers in Prague during that 10-day period. But only 10% of them voted this afternoon.'" On a less serious note, lx writes "Nonplussed by Pluto's recent downgrade from Planet Status, Fox News's own John Gibson does an incredible Stephen Colbert impersonation to correct the 'revisionist history' of the IAU's decision. Exemplifying 'truthiness,' from the article: 'Long ago I learned it was a planet and I see no reason to unlearn it. Why should I?' "
[+]
"Xena" To Be Named Eris 167 comments
rdwald writes, "After over a year of hanging in maybe-planet limbo, newly-classified 2003 UB313, nicknamed Xena, now has a permanent name: Eris, goddess of strife. Its moon will be named Dysnomia, after the goddess of lawlessness — in Greek mythology, Eris's daughter — certainly not a reference there... I don't think I'm alone when I say, 'Hail Eris! All hail Discordia!'"
In the same IAU announcement (PDF), Pluto was given its official minor planet number: 134340.
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waiting (Score:4, Insightful)
Re:waiting (Score:5, Insightful)
I am much happier thinking that astronomers are in a hole somewhere in the middle of the night staring into the sky adding to the human body of knowledge, then sitting in a giant auditorium fighting over meaningless bullshit and operating at the lowest forms of the intellectual discourse (semantics and sophistry... voting on definitions.. oh jesus). I liked it better when a bunch of people sitting in a giant room yelling and screaming about nothing and being otherwise useless was called Congress...
This is an argument over terminology. There is nothing of any value, at all, at stake here. This is so people can refer to planets and have it mean something, as a word. This is basically the equivalent of Webster writing down what a word means. This isn't even actual science.. it's just a bunch of people trying to formalize their industry's terminology to facillitate communication. The scientific value of a probe is going to be exactly the same if Pluto is a dwarf planet, a pluton, a planet, a really large Kuiper Belt Object, or anything else.
Just pick a god damm definition. I'm starting to think astronomers are doing this on purpose to get themselves alot of free press and airtime. Professors everywhere are making 6 minutes TV and radio spots to explain this stupid "controversy". It's semantics. Nothing more, nothing less.
Re:waiting (Score:5, Funny)
Kind of like Slashdot, you mean?
Re:waiting (Score:5, Funny)
Re:waiting (Score:5, Funny)
No, it's a plausible deniability thing. If they're good aliens, they come here, we explain that we were very primitive but have since learned to count.
If they're bad aliens, we say "What? We only have eight planets. This isn't the solar system you're looking for. Move along..."
Re:waiting (Score:5, Funny)
we defeat them with reclassification? (Score:5, Funny)
IAU: "i hearby reclassify you from bad alien to good alien"
**poof**
(good) alien: "E.T. Phone home..."
Re:waiting (Score:5, Funny)
You're new here in science, aren't you?
Just pick a god damm definition.
Big Ass Round Thing! Big Ass Round Thing! Big Ass Round Thing!
Come on people, let's show these Bozos the power of the Web. Send letters, emails, customized party poppers, whatever; and let 'em know we want our Big Ass Round Things.
KFG
Consistent terminology is crucial to any field (Score:4, Interesting)
Nostalgia or neat names your kids like are no reason to violate the rules of your field. AIDS was orginally categorized as a form of cancer, but then we found that it's not a cancer, so we stopped calling it a cancer. It's simple, really. Once you disprove something, it makes no sense to go on believing it.
The simple truth is that if you call Pluto a planet, then you also have to call Ceres and potentially hundreds of bodies in the Kuiper belt planets as well. Pluto does not dominate its orbit around the sun, it shares it with Charon, they spin around each other, one is not a moon of the other. None of the other planets in the solar system have such a symbiosis, they all have moons that orbit them. What shall we do when we manage to spot specific planetary bodies in distant solar systems? "let's see... hrm, that's a class-M planet, that's a gas giant, that's a dead rock, all of these have moons and they're spherical and dominate their orbits, but hey, here's a neat looking body there dancing with another body, I guess that's a planet too, let's call it Mickey and forget the thing it's spinning with." Where does it end? We need a concise definition that works every time, no exceptions.
As it is, with that gold disc in the voyager spacecrafts showing the planets of our system, it's doubtful ET will find us now since he'll see our system has only 8 planets but his directions said there would be 9. If he stumbles into the system anyway, and finds that's he's got the right place, he's going to think we're a bunch of retards for saying we have 9 planets
Re:Consistent terminology is crucial to any field (Score:4, Informative)
What makes the Kuiper belt so different that its inhabitants get to be planets, and the asteroids don't?
Re:Consistent terminology is crucial to any field (Score:4, Informative)
Pluto should have never been classified as a planet, and was only done so for political reasons, not scientific. It's not in a standard orbit like a planet, it highly eccentric, crossing Neptune's orbit as well as being tilted significantly in the plane of the solar system as compared to the other planets. It's moon is over half its own diameter.
It's probably a rock/ice blob from the Oort cloud that came too close to one of the gas giants and ended up in a roughly stable orbit. It's more like a failed comet than a planet.
Re:waiting (Score:5, Insightful)
Everyone at my house just took a vote - We unanimously voted that BeeBeard should send us all his money. And we don't want to hear about sour grapes, like "too few people voted to have any meaning" or "you didn't consider my input first".
The rest, I agree with. These guys have taken to arguing semantics, not a good sign for their future. However, I don't think most of us need to worry, because no one cares what they decide. Consider the definition of a "constellation" - Most of us consider things like the Big Dipper or Orion as constellations; astronomers call those "Asterisms" and refer to large nondescript (except by coordinates) parallelograms of sky as "true" constellations.
Re:waiting (Score:5, Insightful)
Originally the Sun and moon were classified as planets. Should we keep that definition for historic reasons?
What about all the round trans-Neptunian objects? 2003 UB313, Charon, Sedna, Quaoar, or the 1000 others? Should all those be planets as well? And if you're gonna include at least everything in the Kuiper belt, you might as well include all the round asteroids. And all the round Trojan bodies.
Shoot, while you're at it, why don't we just include every single comet in the Oort cloud? Then the solar system would have billions of planets. Take that 55 Cancri!
I don't understand why people have a hard time "letting go" of Pluto as a planet... It's floating in a cloud of objects, just like Ceres. And just like Ceres, once we discovered that it's just one of many (some even larger) in a belt of objects, it got reclassified. What's so freggin' hard to understand?
Re:waiting (Score:5, Insightful)
What more information do we need about Pluto? There's lots to learn, but nothing that bears on the argument at hand.
You seem to think that "planet" is a word astronomer's agree on, and we just don't know enough about Pluto to say whether it is one. It's the other way around.
Despite the headlines, astronomers are not arguing over whether Pluto's a planet. They're arguing over the right way to define "planet". Pluto's relevent only because lots of people are used to thinking of Pluto as a planet, and don't want a definition that leaves Pluto out. But that's hard to do. There are millions of trans-Neptunian objects. If Pluto is a planet, than so are many of them.
I heard an interview with an astronmer who described our solar system as it would be seen by an alien arriving from outside. The first thing the alien would notice is the huge cloud of trans-Neptunian objects. Then much further in he'd see 8 planets. Or maybe he'd view them as 4 rocky worlds and 4 gaseous worlds. But in any case he'd differentiate all 8, which orbit pretty much in a single plane, from the TNOs, which form a sort of donut-shaped cloud. If he noticed Pluto at all, he'd definitely classify it with the TNOs.
Then suppose he met us, and we tried to tell him that Pluto isn't a TNO, it's a planet, just because it was discovered before the TNOs. He'd think we were being pretty arbitrary — and he'd be right.
Re:waiting (Score:5, Insightful)
So? If there's more trans-Neptunian objects out there big enough to be called planets, our system has more planets. What's the big deal? There's nothing magic about the number 9 (or 8) as the number of planets. When Uranus was discovered, the number of known planets increased; it increased again with Neptune. If we find more planets out there, it will increase yet again. No big deal.
Re:waiting (Score:5, Funny)
Then they'd have to learn things like, "My Very Eager Mother Just Sent Us New Pajamas Which Didn't Fit Properly So We Had To Go Back To Walmart And Exchange Them For Better Ones But We Didn't Have The Receipt So There Was Nothing Else To Do But Cause A Distraction In The Store And Run Out With The Correct Ones And Then We Went To McDonald's And I Had A Big Mac With Small Fries But Then..."
Re:waiting (Score:5, Informative)
Your post intrigued me, and after some quick research with the help of Google, I agree. You can fire up Celestia and actually see some of them, just make asteroid orbits and names visible. Pluto fits right in with them; it seems to be the largest of them.
For you unbelievers, here's a list. These objects are all out of the "normal" plane of orbits, just like Pluto.
Name, Radius
Pluto, 1,151km
Ixion, 600km
Quaoar, 625km
Orcus, 800km
Varuna, 450km
And these are just some "nicely named" ones. See "2003 EL61", "2005 FY9", etc for more examples. And you can add more [celestiamotherlode.net] as well. For those with computers that aren't slow, this page [cornell.edu] contains a Celestia ssc of 1007(!) TNOs. Doughnut shaped indeed.
Also, there is a class (like 20%-30%) of them called Plutinos [cornell.edu] which share Pluto's stable 3:2 orbital resonance with Neptune. How did this come to be? There are theories [hawaii.edu], but nothing definitive yet.
The debate will continue, but if you look at that Celestia ssc of 1007 TNOs, it is pretty clear that Pluto is not a "major planet". If it is, then we've got dozens, possibly hundreds of them.
(Apologies if this has been covered before.)
Re:The whole argument seems quite ridiculous (Score:5, Insightful)
Re:waiting (Score:4, Funny)
Fuck me? Fuck you, you fatuous rube with your puerile lexicon.
More discovery.... please (Score:4, Interesting)
When they demoted Pulto (Score:3, Interesting)
What more can you say?
Re:When they demoted Pulto (Score:5, Insightful)
When Aristotle pointed out that the Earth wasn't flat, it pissed off a lot of people. When Darwin published The origin of species, it pissed off a lot of people. When climate scientists pointed out the dangers of anthropogenic climate change, it pissed off a lot of people. When they found that Pluto, like Ceres, was within a belt of similarly sized objects, it pissed off a lot of people.
I suspect the reason these people were pissed off is because they can't fathom that new observations means that what they were taught before was wrong, and that the new information gives a better approximation of reality.
Now that we have Pluto out of the way (Score:5, Funny)
Re:Now that we have Pluto out of the way (Score:5, Funny)
The first guy to rally against that would have to be mighty brave...
Fuck the pissy "scientists" (Score:4, Insightful)
If they were real scientists, they'd accept the new designation. That's how science works. You modify your model of the universe as new information becomes available. Clyde Tombaugh found the first of an unknown class of objects because Pluto happened to be the closest and easiest to see. They just called it a planet because they lacked the information we have. But now we know about the Kuiper Belt, and have adjusted the definition of Pluto accordingly. Mode me a troll, but stop with the sentimental bullshit. Rather than :losing" a planet we've gained a whole new neighborhood of the Solar System to explore.
i just wrote a story about this at kuro5hin.org (Score:5, Interesting)
the issue centers on one the IAU itself says it hasn't addressed with it's new definition of a planet: extrasolar systems. as new telescopes come on line with more resolving power, our bestiary of planets is going to grow by leaps and bounds. it will render the debate over pluto moot
i think a definition of planet should be:
-round, with a significant atmosphere
-this is distinct from a gas giant, which should be considered closer to stars than to planets (round, mostly gas: really just stars without enough critical mass to ignite fusion)
-and distinct from a moon (no atmosphere, but still round)
-asteroids, comets, etc make up the miscellany
and notice, most importantly, i said nothing about what something orbits. what something orbits is really secondary in consideration to what something is composed of. if we find an earth-like "moon" orbiting a gas giant in another solar system, is what it orbits really the first consideration in picking what to call it? no, composition should come first, orbit second. so you could have a moon of the sun (pluto), or a planet of saturn (titan), or an asteroid of mars (deimos/ phobos, etc.)
so this system demotes not only pluto, but also mercury. while promoting titan. so our solar system is composed of:
-4 planets (venus, earth, mars, titan)
-4 gas giants (jupiter, saturn, neptune, uranus)
-and countless moons (of the sun and the planets)/ asteroids (of the sun and the planets)/ comets/ ring systems/ kuiper belt, oort cloud objects/ etc
really, as we see more and more exotic arrangements in extrasolar systems as new telescopes come on line, this debate about pluto will look more and more pedantic. and the IAU should really begin focusing on a more rigid definition no matter what, something they said they weren't doing at their last congress. we will soon have a vastly larger catalogue of strange orbital objects/ arrangements out there. pluto is small potatoes... literally
Oh Pluto (Score:5, Funny)
Better tell solar system (Score:5, Funny)
What can the IDers take from this? (Score:5, Insightful)
Yes, I know that this whole planet thing is just taxonomy, but do they? Do the politicians really understand that, either?
Re: (Score:3, Insightful)
Objective definition? (Score:3, Insightful)
They demote pluto because it hasn't cleared the neighborhood of its orbit because its orbit intersects the orbit of Neptune. But doesn't this necessarily mean that Neptune has not cleared its neighborhood and therefore is also not a planet?
What does clearing the neighborhood mean? To me it suggests the planet should have no moons either?
If you are going to make a big deal and change the definition of something like this you should put a heck of a lot of thought into creating a definition that is objective and not open to interpretation.
The story so far... (Score:5, Funny)
~800 bc - Roman god of the underworld.
05-01-1930 - New planet. Also Mickey's new canine companion. Retains position as god of the underworld.
08-10-2006 - Still a planet. And a dog. Takes time off as god of the underworld to "spend more time with his new ceslestial family".
08-24-2006 - Demoted as a planet. Reclassified as a "dwarf planet" (or as they prefer to be called "Little planetiods"). Resumes job as god of the underworld.
Today - A planet again. Maybe. Title of "Roman god the the underworld" undisputed. Still a dog.
(ps. Tomorrow - Profit ???)
Open letter to all US scientists (Score:4, Insightful)
Humanity has arrived at an inflection point in our history, one whose influence will steer our course for decades, or, more likely, centuries. The post-millennial rise of both Islamic and Christian fundamentalism tears at the very skirts of the Enlightenment.
Your fellow citizens have twice elected an inarticulate and violent demagogue as President, a man who has expressed deep personal doubts [bbc.co.uk] about the validity of the scientific method and its relevance in America's primary-school classrooms. Three-fourths [biblicalrecorder.org] of the adult population profess a belief in angels; two-thirds [wnd.com] believe the Christian Bible is the literally-true word of their God. Over half [cbsnews.com] state that humans were created by God in their present form.
One American adult in one thousand [rrmtf.org] can state the freedoms guaranteed by the First Amendment to the Constitution.
Meanwhile, to the elected representatives of this singularly-unenlightened population, you, America's scientists and engineers, have cheerfully handed control of several thousand thermonuclear weapons [cdi.org].
And now you're bickering endlessly about... whether or not Pluto is a planet.
Cut this shit out. Now. I don't want to live in another Dark Age, or worse, die upon the threshold of one.
Let Pluto be Pluto, whatever Pluto is, and let's put our heads together and figure out how to deal with the delusions we've created for ourselves here on Earth. We need intellectual leadership, not semantic panem et circenses.
Answers? Sorry; you're the scientists, I'm just some obviously-unlaid AC, ranting into the night on Slashdot's nickel. If I had any suggestions, believe me, I'd be making them, but I don't.
But come on. We've got to do something productive here.
misses the point (Score:3, Interesting)
The final "definitions" that they came up are not scientifically useful or even useful for any reason. No better than the previous enumeration of planets. Really a lot worse in that now by definition planets only exist in our solar system. So, all those things that orbit other stars... oh well now they are just thingies that orbit other stars. The draft proposal seemed much better by comparison and provided a much more broadly applicable definition. Hell kick pluto out of the main planets if you want, but do so by increasing some arbitrary size threshold and then don't use planet as part of the name for whatever you are left with, at least if by definition it is now not a planet or any type of planet. Even the dorky sounding "pluton" would have been better than "dwarf planet"
And you have to imagine we are going to be finding a lot more planets around other stars in the coming decades as telescopes and processing power improve. or we would have, now we can't since all we can find is something that has no category of its own, unless they too will get a two word name that includes the word planet, such as "extrasolar planet" even though the word "planet" alone is not applicable.
And the part about clearing the neighborhood of the orbit part of the definition seems like it could be problematic from an observational standpoint. The idea that even if we agree to extend this new "definition" to other star systems, then observations probably won't be sensitive enough to be able to determine if the planet-like object has cleared all the asteroids from the "neighborhood". So, until we actually go to another star system, the likelyhood of finding another object and consitently (with the definition) say that we have found a planet will be nil.
Those of you who think the problem some of us have with these problematic new definitions is merely nostalgia, think again.
Bring back the draft proposed definitions and maybe tinker with those a bit. These ones they came up with need to be thrown out.
What was wrong with the first suggestion? (Score:4, Interesting)
* It is round under its own gravity
* it is not already classified as a star
* It is not a satellite to something else not classified as a star (ie. when the common point of rotation is located within the body of the other object)
A possible fourth criteria could be:
* It orbits something classified as a star
though I'd be happy without that criteria, making solitary, wandering bodies be called planets as well.
Sure, that will probably get us planets by the dozen as we get a clearer idea of what't out in the edges of our system - but why is that a problem? It's not like having nine planets has some mysterious significance, and it hasn't been nine - or eight for that matter - for very long either.
A "planet" is . . . (Score:4, Interesting)
. . . something you look at and say, "hey, that's a planet."
No, seriously. Given all the historical baggage surrounding the term "planet", people shouldn't be trying to use it as a scientific term in the first place. If you want something that can be used to scientifically denote a certain class of astronomical objects, call them "primary satellites" or something. What's wrong with saying something like this, for example? "A planet is one of the nine satellites of Sol: Mercury, Venus, Earth, ..., Pluto; or a similar object orbiting another star that is widely recognized as a planet." That keeps the status quo with respect to our solar system, which doesn't seem to have hurt anything in the 76 years it's been around, and lets public opinion decide on anything else that pops up. Which leaves astronomers free to spend their valuable time actually watching the sky rather than trying to convince people that something that looks like a planet and smells like a planet isn't actually a planet.
there's only one reason for all this (Score:4, Interesting)
In order to find this planet, and ensure that Lovell wasn't primarily remembered for his fanciful and incorrect thesis regarding life/civilisation on Mars, a junior astronomer was set to work searching for this suposed super giant Gas Planet.
Note that I say Junior, no-one else wanted the job, no-one....
Instead of a Huge Gas Giant, he found a tiny rock. As it turns out this was the first sighting of a Kuiper Belt Object, a noteworthy acheivement in itself which was sullied and robbed of its true importance as a milestone in astronomy due to the politics of the day within the astronomy movement.
So, this tiny rock was hailed as Lovells planet, in spite of the ludicrous nature of this claim, given the obvious disparity between the predicted object, and the one found. It could never have caused the gravitational perturbance by which the presence of the gas giant was inferred by Lovell.
It's status as a planet, whilst debated by some then, and many since, has been assured due to this fear of blackening Lovells name.
Interestingly, none of the astronomers who wanted Pluto to be a planet would consider calling our moon, or Ceres planets, even though admitting Pluto into the list of planets meant these, among others, would now qualify.
It is this bizarre situation that the decision regarding Pluto is seeking to resolve. That not many astronomers were there to vote is beside the point. The vote was known to be taking place a long time in advance (many months), it wasn't a rushed secret ballot or anything.
The people who want to discredit the vote don't actually have an alternative classification, they just want the ambiguity to remain.
In effect, what we have here is an old fashioned cat fight among supposedly mature people of science (predominantly men).
Scientific classifications change all the time... (Score:5, Insightful)
When I was a kid, there were Baltimore Orioles. Then they decided that they were really the same species as Bullock's Oriole and both of them got renamed the "Northern Oriole." Then molecular genetics studies suggested they were really all that similar and now there are Baltimore Orioles again.
My science teachers were old enough to remember when _their_ sciences teachers had said "There are ninety-two elements. There have always been ninety-two elements. There will always be ninety-two elements." And "elementary" particles? Don't get me started...
The horseshoe crab was Limulus polyphemus. Then it was Xiphosura polyphemus. Now it ''seems'' to be Limulus again... or is it?
Classification is prescientific activity. It's very important but it's always arbitrary and subject to change.
Re: (Score:3, Insightful)
Seen from outside, the solar system has two large gas planets (Jupiter, Saturn) and two small gas planets (Uranus and Neptune). If you look closely, you see two small rock planets (Earth, Venus), and various smaller debris, like Mars, Mercury
Re:Pluto in School (Score:4, Informative)
Quoth the wikipedia, "Mars has half the radius of the Earth and only one-tenth the mass, being less dense, but its surface area is only slightly less than the total area of Earth's dry land".
Re: (Score:3, Insightful)
Re:Pluto in School (Score:5, Insightful)
At least the shitty schools, anyway. Maybe your statement is an indictment on how shitty the school system is.. unfortunately, I don't think so. I understand your point that schools have alot of switching costs, and that the 9 planets concept has alot of inertia, but if scientists decide Pluto isn't a planet, then it's not a planet.. I expect my child's school to teach them that. I expect my child's school to teach my children about what real scientists do, and what real science is going on, and even about what real scientists are arguing about. Once scientists finally agree on what is a planet, and who the planets are, I expect my school to keep up. If science changes... schools are supposed to change with it. This idea that you shouldn't have to keep up with science because it's inconvinient... well, don't make me invoke the intelligent-design drama If you aren't going to teach kids the things that science agrees is correct, then what exactly _are_ you going to teach them? Whatever you feel like? Whatever you were taught?
Re:Pluto in School (Score:5, Funny)
Re:FP? (Score:5, Insightful)
Fine, then - have it both ways (Score:5, Funny)
The rest of the world can use the metric planets that evolved in our solar system.
There. Everyone happy now?
Re:Fine, then - have it both ways (Score:5, Insightful)
You're actually serious, aren't you? In what way exactly does it kick any ass? The metric systems covers lenght, volume, force... all consistent and based on one, single meter.
The "standard" (that is, the standard in the US and hardly anywhere else) is based on how many definitions for lenth etc.? How many pints of fuel are in a rocket? Would that be american pints or british dry pints or british liquid pints? How many inches go into a mile? Would that be a normal mile or a nautical one? How many ounces does a quibic yard or foot of water weigh at room temperature?
The so called (by you) "standard" system is a mess, historically grown and a nightmare to handle.
Kuiper biggotry (Score:3, Interesting)
There wasn't a definition before (Score:3, Insightful)
They didn't change the definition of a planet; there simply wasn't any precise definition of a planet before. As for all of you who want to keep with tradition, I'll refer you to my previous posting on this [slashdot.org].
If you've got a strong case why Pluto should be
Pluto's smaller than our moon. Is it a planet? (Score:5, Insightful)
Geez, you make it sound like they're just some random cranks who got together. This was a meeting of the IAU. Common human consensus had tomatoes as not being fruits and dolphins as fish before people sat down and came up with a consistent definition.
Pluto's essentially grandfathered in from a time when we hadn't yet found other objects in its size class. I hope you realize that Pluto is only about 2300 km across while our own moon is about 3500 km across. Are we in a double-planet system, or is there some logical reason you can think of for making a smaller object than our moon a planet while our moon is undeserving of the status?
I think it's high-time we demoted it as nothing more than an oversized trans-Uranic asteroid. I mean, it doesn't even operate on the same elliptic plane as the planets do and it has a "moon" that's half its size. The only reason anyone cares is a knee-jerk anger over having some childhood lesson overturned.
Re:Pluto's smaller than our moon. Is it a planet? (Score:5, Funny)
Are you suggesting that witches are not actually made out of wood?