Demote The IAU!!!!

alokmohan · Aug 29, 2006

Other body larger than itself

bviously it didnot mean .SUN.In case of earth larger that itself means jupiter or like that.Thats the meaning I make out.

vidar · Aug 29, 2006

derekmcd I think using this as a standard would provide confusing results. Take a very large/very small 2 body system and place it close enough to the sun, it is a binary system. Take 2 objects the nearly the same size and place it far enough away from the sun and and it is a planet/moon system. That doesn't make sense... at least, to me it doesn't. -------------------------- Defining a dwarf planet should be more about the object’s nature, than its neighbourhood. See it the other way. Any planet that happens to pass Jupiter will either be caught in orbit or swallowed up whole. It’s not right to rename a planet to a satellite moon just because of its new path. I think the Galilean moons really are Galilean dwarf planets. http://solarviews.com/browse/jup/jupsystm.jpg

cuddlyrocket · Aug 29, 2006

"Defining a dwarf planet should be more about the object’s nature, than its neighbourhood." Which was the very crux of the argument about the definition of a planet at the IAU, and we all know how that turned out. And we all also know that the majority at the IAU eliminated satellites from the dwarf planet definition, probably for the same reason. People are entitled to contrary views of course.

ittiz · Aug 29, 2006

I know what the moon's orbit around the sun looks like. That doesn't mean it doesn't orbit the Earth. Check this out: http://en.wikipedia.org/wiki/Hill_sphere

johns805 · Aug 29, 2006

Hi: My starter post was in part emotional and hyperbolic...It is what it is, but there's more and I'm open to it as long as it's expansive... It is uncomfortable and disconcerting to me when a small group of self installed, unelected "experts" thinks it has some devine, pre-ordained entitlement to confuse, dismiss and denigrate what has been recognised and accepted as a set of increasingly verifiable facts for several decades...To consider the sentiments, sense of wonderment, opinions (educated or not) and enthusiasm of millions as a matter of inconsequence is the height of an arrogance of fools....There are serious matters of credibility, funding and politics here...For any action, there is a reaction....Support is given and taken away... Submitted for your consideration is a point of view that is gaining support among a diverse community every day: Mission Statement Members of the SP3 (Society For The Preservation Of Pluto As A Planet) are dedicated to the proposition that Pluto has been and always should be considered the ninth planet of our solar system. To support our proposition, let the following facts be placed before a candid world. Pluto was discovered in 1930 by Clyde W. Tombaugh, who spotted it right where a new planet was expected to be found. Pluto has three moons: Charon, Nix, and Hydra. Only planets have significant-sized moons. Pluto's radius and mass are comparable to those of the inner planets of the solar system and the Galilean satellites. Both the radius and mass are much larger than that of the largest asteroid, Ceres. Pluto has an atmosphere. Only planets or planet-sized objects have atmospheres. Pluto is not a comet, an asteroid, or a moon, but it is a large object that orbits the sun of our solar system. It therefore must be a planet. http://www.plutoisaplanet.org/ Best Regards! ~

serak_the_preparer · Aug 29, 2006

Pluto was discovered in 1930 by Clyde W. Tombaugh, who spotted it right where a new planet was expected to be found. Pluto has three moons: Charon, Nix, and Hydra. Only planets have significant-sized moons. Pluto's radius and mass are comparable to those of the inner planets of the solar system and the Galilean satellites. Both the radius and mass are much larger than that of the largest asteroid, Ceres. Pluto has an atmosphere. Only planets or planet-sized objects have atmospheres. Pluto is not a comet, an asteroid, or a moon, but it is a large object that orbits the sun of our solar system. It therefore must be a planet. Johns805, the facts you offer in support of Pluto's status work for me. Pluto may have had less going for its ranking as a planet when it was given that status back when it was discovered. But just recently, as you point out, we have found Pluto to be, in fact, a double planet orbited by two lesser moons. You have also noted the double-planet's better half possesses a known atmosphere. Though I'm not much a joiner, I may be forced to make an exception in this case and sign up with the SP3.

MeteorWayne · Aug 29, 2006

All your points are good. However, pluto is just one of many. All you 3 P'ers can argue your valid points. Mine are valid as well. Now you may think the IAU is self installed experts, but they are not. They are an organization of astronomers worlwide, experts in the field, for what ever that's worth. How many research studies have you published? For me the answer is none. How long have you been considering this issue? For me, it's at least a decade. The IAU does not presume any devine (sic) pre-ordained entitlement to do anything. They, as the accepted arbiter of these issues, have come up with the first "official" definition ever of what a planet is. I happen to disagree with some of their points. Here's one of yours " Pluto was discovered in 1930 by Clyde W. Tombaugh, who spotted it right where a new planet was expected to be found. Except as has been repeatedly shown this was a PURE ACCIDENT. Luck does not make a plutino (KBO/TNO) a planet. Pluto has three moons: Charon, Nix, and Hydra. Only planets have significant-sized moons. First of all, I believe Pluto Charon to be a binary KBO (or dwarf planet, or plutino). Many KBO's have moons. It has been suggested that a minimum of 20% and perhaps as many as 50% of KBOs may be multiple objects. Pluto's radius and mass are comparable to those of the inner planets of the solar system and the Galilean satellites. Both the radius and mass are much larger than that of the largest asteroid, Ceres. Not really, pluto's mass is 20 times smaller than Mercury's and is again, smaller than other objects in the same orbit. It is smaller than 6 satellites plus our moon. And that justifies it being a planet how? It's mass and size are larger than Ceres? It's not a planet, so what's your point? <fo></fo> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

adman69 · Aug 29, 2006

What about Mercury? It's pretty damn tiny too...a little larger than Pluto but much smaller than Neptune, Uranus, etc. Mercury shouldn't be a planet either...

MeteorWayne · Aug 29, 2006

Mercury is 20 times the mass of pluto, and is in it's own unique orbit around the sun. Yeah it's small, but compared to it, Pluto is a dwarf. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

adman69 · Aug 29, 2006

Again the same arguements...Mercury is less than 5000km at it's equator. It's mass is only because of it's iron gut. Pluto also has it's own unique orbit, yes? It's mass can't be conclusivly proven until 2015 at the earliest...so what is size? What is orbit? The IAU's new definition just made it even harder to define planets. So what if it's sentmentalism? Pluto has been an accepted planet by the IAU since it's inception. It's discovery was a technical marvel and a pivotal, historical moment for mankind. Leave it be!

kheider · Aug 29, 2006

The discovery of Pluto led to many questions about the planet. One of the most puzzling was the fact that Lowell had predicted that Planet X would have a mass 6.6 times that of Earth. The tiny dot that was actually discovered could not possibly be that big, unless it was extraordinarily dark. Estimates of its diameter, for example, ranged from 6,000 to 14,000 kilometers. After the discovery of Charon in 1978, which permitted determination of the mass through a few simple calculations, the mass of the Pluto system was determined to be about 500 times smaller than that of the Earth. This was a long-term mistake and I am glad that it is now corrected. There are 19 moons (7 BIGGER THAN PLUTO & 12 smaller) in the solar system that are worthy of being called planets, but we do NOT call them planets because they orbit around DOMINANT spheroids that we do call Planets. Saturn moon Titan is a great example. With it's thick Nitrogen atmosphere resembling what the Earth was probably like billions of years ago, it is the most EARTH-LIKE spheroid in the Solar System. Yet, by either proposed definition, it is a satellite, not a planet! If they really want to be all inclusive they have to open up the definition of Planet to include the current 19 moons that would be Planets except that they are not GRAVITATIONALLY DOMINANT in their orbit around the sun. -- Kevin Heider

adman69 · Aug 29, 2006

Science doesn't always have to be the right answer. Pluto is a planet because it has always been a planet and it always will have an orbit around our sun with it's own unique, "cleared out" and hydrostatic disposition. That's all I can say about that.

vidar · Aug 30, 2006

johns805 Members of the SP3 (Society For The Preservation Of Pluto As A Planet) are dedicated to the proposition that Pluto has been and always should be considered the ninth planet of our solar system. ------------------------- Consider this illustration; http://www.solarviews.com/browse/misc/plntmoon.jpg Pluto could be the ninth dwarf planet, in size.

vidar · Aug 30, 2006

CuddlyRocket Which was the very crux of the argument about the definition of a planet at the IAU, and we all know how that turned out. And we all also know that the majority at the IAU eliminated satellites from the dwarf planet definition, probably for the same reason. People are entitled to contrary views of course. ---------------------------------- I must admit I have altered my view these few days. Now I am thrilled that we have got a new category called dwarf planets. But I am disappointed that noone seemed to agree on a single one fitting the definition. What is this? Is there a definition, but no real dwarf planets? In my view, nine dwarf planets were discovered long ago. The most known one is our Moon. Next there are the magnificent Galilean four. Titan might be the most interesting of them all. Triton is included due to a size limit. And finally there are Pluto and Mercury that still are free of larger planets domination. http://www.solarviews.com/browse/misc/plntmoon.jpg Looking at the picture I find it obvious. But the definitions don’t quite fit reality. What’s most important, nature or definition?

serak_the_preparer · Aug 30, 2006

except there should be no "force of history" exerted upon a scientific classification scheme. Unfortunately, it is all about the force of history in this case. The original meaning of the word 'planet' has more to do with myths and astrology than science. Over time, our civilization has slowly moved away from the concept of gods patroling the heavens toward actual worlds worthy of scientific scrutiny. That scrutiny, naturally, has everything to do with the history of the technological advances behind it. From Dictionary.com: < />-<>-<> plan·et [plan-it] –noun 1. Astronomy. a. Also called major planet. any of the nine large heavenly bodies revolving about the sun and shining by reflected light: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, or Pluto in the order of their proximity to the sun. b. a similar body revolving about a star other than the sun. c. (formerly) a celestial body moving in the sky, as distinguished from a fixed star, applied also to the sun and moon. 2. Astrology. the sun, moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, or Pluto: considered sources of energy or consciousness in the interpretation of horoscopes. [Origin: 1250–1300; ME planete (< OF planète) < LL planeta, planetes (found only in pl. planetae) < Gk (astéres) plané t ai lit., wandering (stars)] Dictionary.com Unabridged (v 1.0.1) Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006. American Heritage Dictionary - http://dictionary.reference.c</safety_wrapper

serak_the_preparer · Aug 30, 2006

And now along comes the BBC's Paul Rincon to untangle the whole mess: Pluto vote 'hijacked' in revolt A fierce backlash has begun against the decision by astronomers to strip Pluto of its status as a planet. On Thursday, experts approved a definition of a planet that demoted Pluto to a lesser category of object. But the lead scientist on Nasa's robotic mission to Pluto has lambasted the ruling, calling it "embarrassing". And the chair of the committee set up to oversee agreement on a definition implied that the vote had effectively been "hijacked".... Dr Alan Stern, who leads the US space agency's New Horizons mission to Pluto and did not vote in Prague, told BBC News: "It's an awful definition; it's sloppy science and it would never pass peer review - for two reasons. "Firstly, it is impossible and contrived to put a dividing line between dwarf planets and planets. It's as if we declared people not people for some arbitrary reason, like 'they tend to live in groups'. "Secondly, the actual definition is even worse, because it's inconsistent..." But Dr Stern pointed out that Earth, Mars, Jupiter and Neptune have also not fully cleared their orbital zones. Earth orbits with 10,000 near-Earth asteroids. Jupiter, meanwhile, is accompanied by 100,000 Trojan asteroids on its orbital path. These rocks are all essentially chunks of rubble left over from the formation of the Solar System more than four billion years ago. "If Neptune had cleared its zone, Pluto wouldn't be there," he added. Stern said like-minded astronomers had begun a petition to get Pluto reinstated. Car bumper stickers compelling motorists to "Honk if Pluto is still a planet" have gone on sale over the internet and e-mails circulating about the decision have been describing the IAU as the "Irrelevant

MeteorWayne · Aug 30, 2006

No Pluto does not have a unique orbit. It is one of several dozen (that we know so far) plutinos that are in 2:3 resonance with Neptune. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

MeteorWayne · Aug 30, 2006

And they are free to pursue that goal. I will argue the opposite <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

jaxtraw · Aug 30, 2006

"No Pluto does not have a unique orbit. It is one of several dozen (that we know so far) plutinos that are in 2:3 resonance with Neptune." ...and Mercury is one of 9 objects we know to share a near-circular zone around the Sun <img src="/images/icons/smile.gif" /> There isn't another object in the same orbit as Pluto (other than its satellites of course). There are other objects that *cross* that orbit but that isn't the same thing. Why does sharing a *resonance* exclude a planet? Pluto's orbit is as unique as any other orbit. It has a unique incilination, aphelion, perhihelion and blah de blah. And what of Sedna? What arbitrary qualification will we impose on that to prevent it daring to sit at the top table with the mighty Planets? How many objects do we know of that are in Sedna's lonely "neighbourhood"? Or are we saying that there are loads of discrete orbits within the first few AU of the Sun, and then everything past Neptune is one big "orbit" and thus crowded by neighbours in that vast expanse?

MeteorWayne · Aug 30, 2006

...and Mercury is one of 9 objects we know to share a near-circular zone around the Sun Exactly! That makes them planets . <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

MeteorWayne · Aug 30, 2006

OK, if you're not getting the point, I can't explain it any clearer. Pluto is one of dozens of objects, some of which are larger than pluto, all of which are smaller than Mercury which revolve around the sun in orbits that are basically the same. Yes each one is different to some extent, but their orbit is controlled by Neptune. All spend most of their orbit outside of Neptune's distance. If Pluto had not been descovered first, we'd not even be able to find it among all the others. Have you looked at the outer solar system animation I posted above? If not, please do. You can not differentiate pluto from all the other plutinos, except that the animation has a white cross instead of a white dot. It is not unique! A tiny chunk of rock/ice, smaller than 7 moons and Mercury, travelling with dozens of brethren is not unique enough to make it a planet. That's just my opinion, and I'm stickin' to it <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

jaxtraw · Aug 30, 2006

You're missing my point. You've slid from "in the neighbourhood" to "have a similar *type of* orbit" now. I really think you're picking arbitrary characteristics. Besides all else, where does the IAU definition say "planets must not have a resonance with another planet"? The other point; I'm not trying to distinguish Pluto from its brethren. That would indeed be silly. Either any spherical world is a planet, or not. Pluto isn't special. I think they're all planets, if they're big enough to become spherical under their own gravity. They may be a sub-type called Ice Planets or Dwarf Planets, but planets they are. I don't see why they need to be "unique enough" to be anything. THere's nothing special about being a planet. The galaxy must contain *trillions* of them, all manner of weird and wonderful types in all sorts of orbits- some no doubt even adrift in interstellar space. Why on earth must we think them "unique"?! Somebody mentioned another confounder- the idea that it's a twin planet and Charon should be a planet. That makes no sense to me. By common agreement, secondaries are satellites. In the Pluto system, Pluto is the primary and Charon the secondary- Charon isn't a dwarf planet or any kind of planet; it's a moon.

MeteorWayne · Aug 30, 2006

Pluto isn't special. I think they're all planets, if they're big enough to become spherical under their own gravity. They may be a sub-type called Ice Planets or Dwarf Planets, but planets they are. I guess that's where we disagree, and it's not a point we're likely to shift on. I prefer planetino to dwarf planet, but that's a small (haha) point. I've not considered Pluto a planet since I started to think about it 10 years ago. (Before that, I never even thought about it) To me, pluto is but a piece of the rubble beyond Neptune. We'll have to agree to disagee. I'm OK with that <img src="/images/icons/smile.gif" /> Somebody mentioned another confounder- the idea that it's a twin planet and Charon should be a planet. That makes no sense to me. By common agreement, secondaries are satellites. In the Pluto system, Pluto is the primary and Charon the secondary- Charon isn't a dwarf planet or any kind of planet; it's a moon. Again, here we'll have to agree to disagree. Pluto and Charon are a double "whatever they are". Charon doesn't revolve around Pluto; it revolves about a point in space between them, since their masses are so equal. It's not a secondary, they both revolve around each other, more than Charon revolves around Pluto. So whatever they are, they're a double. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

jaxtraw · Aug 30, 2006

The problem with the Pluto/Charon issue is it creates ISTM an unncessary grey area. Every pair of objects revolve around a barycentre, at least if Messrs Newton and Einstein are correct <img src="/images/icons/smile.gif" /> Again, I see no reason for an unncessary distinction regarding how far from the bodies' centres that barycentre is. It gets you into another irresolvable "definitions" argument. Firstly, if the barycentre has to be inside the primary, there will be annoying borderline cases where it's right on the surface and indeed, due to exentricities and axial tilts, cases where it dives in and out of the primary body at different points during the orbit. In all cases, there will be one body larger than the other (even by 1 gram!). That's the primary, the other one is the secondary. Simple, straightforward, works for me... In the case of Charon, it's *far* smaller (about 11%? Can't be bothered to look it up) and is clearly the moon. You could make a special category if you like for bodies where the ratio is below, say 10:1 but there's no need for a rigorous definition since it'd only be commonly used by dynamicists studying the dynamics of systems with two similarly sized bodies, and they'd probably set their abitrary ratio as appropriate anyway. I think the problem here is people want everything to be in its own singular category, when really things might be in several categories depending on your point of view. If you're studying large comets, you may want to count some Plutinos as comets, whereas if you're studying planets you may want to consider them to be planets. It really doesn't matter, on those terms. I'm simply arguing that in terms of rational categorisation, it makes most sense to call all the big round things planets then use whatever categories- Plutions, Neptwotinos, Icedwarfinos- best suit the moment. I certainly don't see any point fretting about what a moon is. There's an argument that Earth/Moon i

MeteorWayne · Aug 30, 2006

But Pluto/Charon is not a borderline case. Clearly both orbit a center of gravity between the two objects. There will likely be no others that even come close in the planetary class. Earth/ Moon also doesn't even come close. Clearly, the moon orbits the earth. The barycenter is WELL inside of the earth. I will check and get some actual numbers to go with my statements. And 11% smaller is "far" smaller? That's almost 60/40 in mass. Again, I have not verified these numbers yet, just taking yours at face value. I'll be back when I have the facts <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

Demote The IAU!!!!

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