Talk:IAU definition of planet

See /Archive 1

Binary planet

Here's a good link, which others might think worthy of inclusion: http://www.space.com/scienceastronomy/060816_planet_qanda.html

According to that site, "dwarf planet" is not an IAU definition. This article erroneously leaves the impression that it is.

UTC, apparently Charon and Pluto rotate around each other. Put another way, the center of Charon's orbit is not within the body of Pluto. By contrast, the center of Earth's Moon's orbit is within the Earth, the center of Ganymede's orbit is within Jupiter, etc. --Turtle Falcon 21:06, 16 August 2006 (UTC)

Charon

I'm no astronomer, but is or is not Charon a satellite of Pluto?

By this proposal, Charon and Pluto are a double planet, that is, two planets orbitting each other Nik42 20:21, 16 August 2006 (UTC)

The reason is that Charon does not rotate arround Pluto, the center of rotation is equidistant between both planets.Dr. Guillermo A. Sanz-Berney 21:20, 16 August 2006 (UTC)

The centre of rotation is not equidistant between both planets, although it is in the space between both planets. --thirty-seven 21:22, 16 August 2006 (UTC)

I guess you're right they would have to have the same mass to explain an equidistant barycenter Dr. Guillermo A. Sanz-Berney 06:08, 17 August 2006 (UTC)

Even though Charon may be classified as a "new" planet, what about the system's recently discovered two small moons, because I would find it extremely outragious for a double planet system both orbiting in the same orbit and having two moons. Alastor Moody _(talk) 22:37, 16 August 2006 (UTC)

Why outrageous? If Nix and Hydra orbit the common barycenter of both Pluto and Charon, and since both Nix and Hydra cannot be spheriodal due to their mass, they are, according to the definiton, moons of both Pluto and Charon. Tachyon01 00:04, 17 August 2006 (UTC)

I think that what they need to do is figure out exaclty where the center of rotation is between the two planets. If it is closer to Pluto than Charon, which it probably is becuase pluto is the bigger planet, then, I personally would say what Pluto is a planet and Charon is it's moon. But, of course I am no IAU, and okay I'll let my bias out... I like the idea of UB313 becoming a planet, and I don't mind if Ceres joins either, but I don't like the idea of Charon becoming a planet... I just don't. If this happends then the other 41 found so far have to join too and we've just got ourselves a big mess, in my opinoin. Not to mention re-adding Vesta, Pallas and that fourth one, I can't remember the name. I know they haven't voted yet, but I'm just respoding to with initial reactions. and I also love odd numbers, nine or eleven planets sounds good. (but that's completely subjective for me).Omnibusprogression 11:23, 16 August 2006 (PST)

Ceres is substantially larger than Pallas and Vesta. It is not obvious that they meet the criterion of sufficient self-rounding. Dragons flight 07:24, 17 August 2006 (UTC)

It's possible for planets in a Binary system to have their own moons. Once the centre of rotation is below the surface of the planet, it's a moon of that Planet. So, if the moons' centre of rotation are beneath Pluto's surface(which I believe it is), then they will be moons of Pluto.Eccentricned 15:07, 17 August 2006 (UTC)

Additional questions, Why aren't Nix and Hydra considered planets? (sure they might not have the Hydrostatic equilibrium, but indulge me for a moment) I guess they could each be considered moons of Pluto and Charon, because the barycenter of the Pluto-Charon double planet and nix is within the bounds of the pluto-charon orbits, but similar things happen in star systems too ternary star, and they don't cease calling binary stars binary just because they orbit like a planet would? McKay 03:50, 18 August 2006 (UTC)

The lack of evidence, mainly. If we can find that Nix and Hydra maintain hydrostatic equilibrium AND that the barycenter of the moon falls outside both the surface of Pluto and Charon, then we are forced to concede that it's a polyplanetary system. This doesn't sound bad, this sounds really awesome. Pluto's always been the weird one, and we found a reason to make it weirder. Echternacht 00:00, 19 August 2006 (UTC)

Nix and Hydra will never be considered planets. They are ridiculously small, and are nowhere near the definition of a "planet." Hydrostatic equilibrium is NOT merely a spherical shape, but is specifically a spherical shape maintained by a mass large enough to overcome rigid-body forces by means of its own gravity. This means that a small object that just randomly happens to be spheroidal is not a "planet." Only objects approximately 500-800 km or lager (depending on their chemical composition and temperature), can qualify as planets. As for the other question, what body do they rotate, I am not sufficiently knowledgeable to state whether they should probably orbit the Pluto-Charon barycenter or a different barycenter beneath Pluto's surface, but in either case, they are not a "multi-planetary system," because that would imply they are all planets. If their barycenters are all in space, hypothetically speaking, then the whole thing could be described as a multi-body planetary system, consisting of a binary planetary system and additional non-planetary bodies or KBOs. However, it seems apparent to me from the information being published that the barycenters of Nix and Hydra are probably inside of Pluto, making this question moot--Supersexyspacemonkey 06:12, 20 August 2006 (UTC)

I quite get this, but thanks for the clarification. Like I said before, "If..." I see no overwhelming evidence to make Nix and Hydra planets, but we won't know until we get more information. Echternacht 06:01, 22 August 2006 (UTC)

Nix and Hydra are much further from Pluto and Charon than P&C are from each other. Nix and Hydra orbit the same center of mass ("barycenter") that Pluto and Charon do, outside all four bodies. 64.122.41.167 03:42, 26 August 2006 (UTC)

What is the status of Charon then in the final decision? A dwarf planet? tobywhcheng 02:59, 25 August 2006 (UTC)

Better name

This article probably needs a better name, feel free to come up with one ... Cyde Weys 18:04, 16 August 2006 (UTC)

I'd suggest simply merging it with Definition of planet Nik42 20:21, 16 August 2006 (UTC)

Is there a current IAU definition? I thought that's what this is about - that there isn't one. If I'm on the right track, maybe IAU definition of planet? --Elliskev 20:32, 16 August 2006 (UTC)

• No, there is no current definition of what a 'planet' actually is. I agree with Nik42 in that this article be better suited as part of the larger definition of planet article. Tachyon01 22:01, 16 August 2006 (UTC)

I tend to agree. I think that the split was a good idea in theory, but in practice a section in definition of planet will eventually be reduced and the rest of the article will be rewritten to encompass anything that could be here. Sorry, Cyde Weys, but I think it might be time for a poll. --Elliskev 22:40, 16 August 2006 (UTC)

There is a previous IAU definition, though it was issued in 2001 (and modified in 2003) with a caution that it was only a "working definition applicable to the cases where there already are claimed detections..." http://www.dtm.ciw.edu/boss/definition.html

Also, I believe it best to keep this article separate for now. If the draft definition is voted down, this separate article will be quite justified. Bustter 02:23, 17 August 2006 (UTC)

I believe this article should remain separate regardless of the decision of the IAU. This is not an article about the definition of a planet, but rather an article about an event. For now, the article is about a current event. And if the draft definition is voted for, then this article will be about a historic event, and an important one too. Harperska 20:55, 17 August 2006 (UTC)

The Moon

I read on the Bad Astronomy Blog that, given the Moon's rate of drift away from the Earth, in 40 million years it will classify as a planet under these new guidelines because the center of mass of the combined system will no longer be within the Earth's interior. This might go into the article at some point (if it's true!). --Cyde Weys 19:50, 16 August 2006 (UTC)

The EM barycentre will "erupt" from the Earth when the EM distance is about 520000km. Current distance is 384000km. At the rate of 4.4cm/year, this is something like 3.5 billion years. Probably a bit longer, since the rate will decrease. In any event, even if it did occur in 40 million years, it would only highlight the arbitrariness of the definition. A better "double planet" definition should reflect dynamics: tidal lock comes to mind. Someone notify IAU! mdf 20:24, 16 August 2006 (UTC)

They could just redefine it in 3.5 billion years...if they and we are still around ;) Mucus 02:26, 17 August 2006 (UTC)

• While it is true that the Moon's orbit is growing by 4 cm a year, the Earth-Moon center of mass is moving at only 1/81 of that (the center of mass is 81 times closer to Earth than the Moon). The center of mass will on average be outside Earth’s surface only when the Moon reaches average distance of 81 Earth radii, which may not occur for several billion years. Tachyon01 22:05, 16 August 2006 (UTC)

Under other Double planet definitions the Earth-Moon System already qualifies as a double planet as the moon does not double back on its orbit. I like the offered definition and it makes sense... if the barycentre does rise above the earth's surface then it should no longer be a moon... as it is technically not orbiting the earth... but rather an empty position is space.

Indeed, far from "highlighting the arbitrariness of the definition," any indignation towards the possibility of the moon becoming a planet in several million years time highlights the arbitrariness of those opposed to the new definition. The solar system evolves, and things change, especially over millions of years. If the moon no longer orbits a point within the earth, then it no longer orbits the earth, and it is a planet, like it or not, and insisting that it should remain our "moon" forever and ever until the end of time is just sticking one's head in the sand, and is an irrational sentiment, comparable to arguing that the sun will never become a red giant and consume the inner planets. Let facts be facts, even if our paradigms of reality are forced to change in order to assimilate those facts.--Supersexyspacemonkey 06:29, 20 August 2006 (UTC)

Let's face it, the definition of planets, moons, etc are deeply flawed, if they depend on minor details like having a bit more space between objects (what you call "paradigms of reality" I think is better termed slight changes in the system). This definition seems like the sort of thing that is going to result in pointless debates in the coming years over whether extra-solar objects are planets due to subtle questions about orbital dynamics that can't be observed for a few more years.

So this brings me to my real questions. First, how definitive was this vote? Second, if they should for some reason decide to redefine planets again, what would be the procedure for doing so? -- KarlHallowell 19:31, 24 August 2006 (UTC)

What do you mean by "double back on its orbit"? Huh? --Cyde Weys 06:52, 20 August 2006 (UTC)

As in when its orbit is traced from above... it doesnt move backwards at any point... say if our moon had alot faster orbit... it would double back on its orbit as the Earth-Moon System was moving slower than the orbital speed... Interestingly Pluto-Charon does double back on its orbit... if a draft was made with this as the guideline, we would become the double planet :P

Future event

Would everyone please keep in mind that this is merely a proposed definition being put to wider IAU vote, and not yet an accepted definition. Dragons flight 19:57, 16 August 2006 (UTC)

A new subsection for "Definition of planet"

Will someone please rewrite the end of Definition of Planet to accommodate the fact that it no longer has its subsection? Serendipodous 20:12, 16 August 2006 (UTC)

Sorry for botching up the transfer and not copying the pictures too. Thanks for fixing that. jaco♫plane 20:14, 16 August 2006 (UTC)

Forgive me, but I feel like this section has been hijacked. There's no point in Definition of planet linking to the 2006 redefinition of planet if it doesn't actually mention the 2006 redefinition anymore. And if it isn't going to discuss the IAU debate, than what, pray, is it for?

You know what? I'm putting it back. I don't care about duplication. Right now, DoP NEEDS this section. I did not write that section to be its own article; I wrote it to follow on from what I had already written in the DoP article. If another article uses the subsection, that's fine, but I'm not simply getting rid of it. Not yet. When the definition is voted on and finalised, DoP will, of necessity, be completely redrafted from beginning to end, and when that happens, the subsection will probably go. But not until then. Serendipodous 20:41, 16 August 2006 (UTC)

That basically brings up the entire problem with wanting to choose what information goes in which article and how many articles we need: Whichever way the IAU ends up voting, both articles will probably have to be thoroughly revised and then we can decide what is repetitive. Right now we've got an article for the definition (which, if the IAU votes against, will probably have to be deleted), and another for the debate which will stay if the draft is voted down and probably be merged if the draft is accepted. We still need to see what the official decision is. Tonberry King 20:44, 18 August 2006 (UTC)

Definition question

Can someone write in an explination of "has sufficient mass for its self-gravity to overcome rigid body forces". My guess in my own feeble mind is that it has to contain enough mass for its gravity to force itself to become spherical. Is this the case? — Preceding unsigned comment added by 208.45.168.113 (talk • contribs)

That's an excellent suggestion. I was thinking that the article may lean to the too-technical side language-wise. --Elliskev 22:42, 16 August 2006 (UTC)

Your own "feeble mind" had done an admirable job of inferring the correct meaning from the text. I think this shows that the passage explains itself very well. -- MiguelMunoz 08:48, 27 August 2006 (UTC)

As far as I understand it, your suggestion is correct - the slightly awkward part is (AFAIK) it depends on the material the object is made from - some objects require less mass to overcome the rigid body forces to become round than others simply because they are not so rigid, so some "planets" would be smaller than other non-planets simply because they are more pliable. So if an explanation is given, should it include this (if that is correct?) Neilljones 00:23, 17 August 2006 (UTC)

My guess in my own feeble mind is that it has to contain enough mass for its gravity to force itself to become spherical. That's more-or-less correct. There's a slight caviat, in that the planet's rotation causes the equilibrium shape to be slightly non-spherical, but the difference is (usually) minor. Bluap 04:12, 17 August 2006 (UTC)

Link to Planet

Am I just missing it? There are links to double planets and dwarf planets but not to plain planets. --hydnjo talk 22:55, 16 August 2006 (UTC)

I think I fixed that problem quite nicely. --Brandon Dilbeck 23:01, 16 August 2006 (UTC)

I think that this article should try to be a teensy bit more understandable to your average lay-idiot, such as myself. 68.49.18.12 00:07, 17 August 2006 (UTC)

The article should probably link to all the planets listed in the images too, which are 2003 UB₃₁₃, "Xena", Charon, Ceres, 2003 EL₆₁, 2005 FY₉, Sedna, Orcus, Quaoar, 2002 TX₃₀₀, 2002 AW₁₉₇, Varuna, Ixion, Vesta, Pallas, and Hygiea. Janizary 00:15, 17 August 2006 (UTC)

"Redefinition"?

Is this really a "redefinition"? There is no formal scientific definition to speak of. SYSS Mouse 01:04, 17 August 2006 (UTC)

• There is an atempted definition in the Wikipedia article that was established in 2005. That definition went by "is it round", but with that definition one could argue that there are 53 planets. User:mustang6172

• But there is no current IAU definition of the term "planet" it has always been vague (Latin or Greek for wonderer I believe). This is a proposal to formally define the term "Planet" for the IAU. myork 12:43, 17 August 2006 (UTC)

I must say, I agree that this is a redefinition of the word Planet. The previous definition was: ...heavenly bodies that orbit a star... So if this definition has changed at all it should be known as a redefinition.

Also, the suggestion made to merge this article with definition of planet is a very good idea. Though, since at the current time it is news, I suggest the article remain a seperate article till the definition is accepted around the globe, when it is no longer news.

456 16:23, 17 August 2006 (UTC)

Could you repeat your last sentences at the appropriate place? Thanks. Nick Mks 16:29, 17 August 2006 (UTC)

I suggest we just keep calling it a redefinition because, as far as I know, that's what the IAU and the press in general are calling it. That's what people know it as, whether or not the name is 100% accurate. Tonberry King 20:49, 18 August 2006 (UTC)

I disagree. Why perpetuate a myth that makes this move look capricious? It's not a redefinition; it's just a definition. Keesey 19:45, 24 August 2006 (UTC)

I agree... I do not recall ever hearing about a "definition" of the word planet. I always assumed it was a large object that even had a remote possibility of being able to support life. Tinlv7 03:57, 26 August 2006 (UTC)

Jupiter

Couldn't one aruge that Jupiter (or any Gas Giant) isn't a planet because with out its atmosphere, it's nothing more than a few asteroids and comets? user:mustang6172

• • I'm assuiming Jupiter has a core and the enormous amount of gravity that it has that this core is rounded nicely. :p --Firebird 05:16, 17 August 2006 (UTC)

Wow, just wow ... I don't know why you seem to think that Jupiter is just asteroids and comets with an atmosphere, but that's totally not true. Please see Jupiter for more information. Also our Sun is nothing more than an "atmosphere" by your words anyway ... so if you just take that away there's nothing left, right? The usage of the word atmosphere is very misleading when the gas we're talking about is actually the majority of the object's mass. It's not insignificant like the Earth's atmosphere and you can't just discard it; it's intrinsic to the nature of the object. --Cyde Weys 14:26, 17 August 2006 (UTC)

One couldn't really argue that Jupiter, or any Gas giant rather. They satisfy both requirements of planets, and as well do not have sufficient mass to undergo hydrogen fusion. As to it being nothing but atmosphere, the proposed definition does not distinguish the composition of the planet. It can be made of silly putty and it'll be a planet. Echternacht 00:12, 19 August 2006 (UTC)

I've read over the article on Jupiter, and it confirmed what I already knew: Jupiter has a small, rocky core. That's the "asteroids and comets" I was refering to. Though I was suprised to learn it has a large magnetosphere (that being indicitive of a liquid iron core). The reason I started to question the planetyary status of the gas giants is that I heard an astronomer say that Pluto shouldn't be a planet because most of its mass and volume is frozen methane. User:mustang6172

That astronomer is wrong. Mass is mass, it doesn't matter what it's made from. Frozen Methane wouldn't be atmosphere anyway, it's solid.Eccentricned 03:12, 19 August 2006 (UTC)

Metallic hydrogen drives Jupiter's field, not iron. Dragons flight 03:25, 19 August 2006 (UTC)

The large magnetosphere of Jupiter is not just caused by an internal property, read. Echternacht 04:21, 19 August 2006 (UTC)

Whether or not Jupiter has a rocky core... due to the atmospheric pressure at lower depths the gas becomes compressed into a liquid and finally a solid, descending trhough the atmosphere it would seem a seamless transition hard to define where the "liquid" and "solid" areas begin.

No. The cores are MUCH bigger than asteroids or comets. Even supposing, for the sake of argument, that atmosphere shouldn't count, the statement "small rocky core" is erroneous (or at least it's misleading). It is believed that Jupiter's rocky core is several times larger than the earth, and would be a massive terrestrial planet even if it had no atmosphere. The same is true of the rocky and icy cores of the other gas giants. So no, you could not argue that! ;^) --Supersexyspacemonkey 06:38, 20 August 2006 (UTC)

Actually, I believe you'd be paring away the layers of an onion. The liquid and solid inner layers are there because of the weight of the gas above them. As soon as you strip off everything above a certain layer, that layer would no longer be under as much pressure and would volatilize, driving the new boundary layer inward and eliminating some more mass from the core. Eventually, you'd strip all of the "atmosphere" away, and there'd be nothing left. Or so my intuition tells me.... :) -- Eliyahu S ^Talk 08:03, 21 August 2006 (UTC)

Could it be argued that seeing the Jupiter-Sun barycentre is above the surface of the sun... following the same principle as the double-planet one... Our Solar System is a Binary System with the Sun and a sub-stellar binary (Jupiter), even so, with this definition, Jupiters Moon's would still be moons and not planets as they do not orbit a fusor. This isnt an attack on teh IAU proposal (Im for it)... but its an interesting point!

I think if it were a binary system, the other planets would have to oribt the Sun and Jupiter.Mustang6172 22:37, 22 August 2006 (UTC)

Each star in a binary system can have its own satellites. And Jupiter has bodies of planetary size orbiting it... Ganymede for example

Stripping Jupiter

Jupiter would be a planet no matter what you did to its atmosphere. Its iron-silicate core is about 15 Earth masses; this can be calculated from the planet's oblateness and rotation rate (1). This core is surrounded by liquid metallic hydrogen, then liquid molecular hydrogen, which reaches up to the base of the gaseous hydrogen-helium atmosphere (about 20,000 km below the cloudtops) (1), (2). I had heard speculation that Jupiter may contain large amounts of compressed carbon in the form of diamond, but I started looking into it and the reality is even more interesting: Jupiter may contain "liquid diamond". According to a paper simply called "Phase diagram of carbon at high pressures and temperatures" by Matthew P. Grumbach and Ricard M. Martin, 8 Nov 1996. (journal not known), carbon in Jupiter remains liquid because though the pressures are plenty high for the solid diamond-phase to exist, the temperatures are far *too* high. The carbon melt would be a mixture of two-, three-, and four-fold coordinated atoms depending on the local pressure & temperature (3)pdf. So, if you started vaporizing the outer layers of atmosphere, assuming the internal temperature stayed the same, I suppose you'd get a bunch of amorphous glassy carbon or, if you did it slowly enough for a lattice to form, you'd get graphite. Of course, this would be a tiny amount compared with all the hydrogen and helium, but it'd still be enough to wreak havoc on the pencil industry and you'd have plenty of other wierd phase changes going on in the ammonia and methane component of the atmosphere. If you kept stripping the atmosphere then eventually, the surface pressures would decrease until the various liquid hydrogen phases become gaseous and, finally, the rocky surface would be exposed with further stripping. According to (1), Jupiter radiates lots of excess of heat thought to be leftover from its formation, which suggests to me that the planet we're left with would be highly tectonic. This would be further aggrevated by the release of its atomspheric overburden, probably causing rapid liquification of previously solid silicates in the outer crust, so the end result would be a giant ball of rock with lots of volcanoes. Without knowing the radius of this "core" we can't calculate the surface gravity, but at 15 M_e, it would certainly be extreme. Okay, that's the end of my semi-off-topic speculation. --Aelffin 12:59, 21 August 2006 (UTC)

You all are looking at the wrong question. What does "clearing out the orbital neighborhood mean"? Jupiter by this definition is not a planet. Trojan asteroids are in the orbital neighbourhood of Jupiter. Hopquick 00:02, 25 August 2006 (UTC)

"Clearing out the orbital neighborhood" does not mean that every single thing has been swept up or ejected. What it means is that any small body in the neighborhood has either been ejected, swept up, or coralled into an orbit controled by the larger body. All objects in Jupiter's path are either forced into position by Jupiter, or they're in the process of being ejected or swept up by Jupiter. Thus, there is *no* ambiguity. Jupiter is a planet. --Aelffin 15:20, 25 August 2006 (UTC)

It just means there are no other objects of similar size in the same orbit. Different language that has been thrown around for the last several years to express the same criterion is "comprising more than half the mass of all objects in the orbit." Pluto loses out because it's in an overlapping orbit with Neptune, and Neptune is unambiguously most of the mass in the orbit. 64.122.41.167 03:52, 26 August 2006 (UTC)

That's true, but it couldn't be in an overlapping orbit with Neptune if it weren't in a resonant orbit. We're saying basically the same thing. --Aelffin 18:10, 27 August 2006 (UTC)

Thanks, Aelfinn! That was much more fun than just metallic hydrogen volatilizing to gas and being "stripped" away with the rest. :) It also makes the sci-fi concept of "scoop-mining" for hydrogen as a near-term replacement for our current petroleum-based economy more politically viable. Even if we mined ALL of the hydrogen over the coming centuries (and the way we humans accelerate our energy consumption I doubt it would take millennia) we could argue that there would still be a substantial planet left in orbit that dwarfs the inner rock balls, so why worry? ;) ("Environmental impact study? We don't need no stinkin' environmental impact study!") Well, it's been fun, but now I have to earn my paycheck. :( --Eliyahu S ^Talk 6:09, 28 August 2006 (UTC)

Not 12 Planets?

This sentence in the article "Despite what has been claimed in the media, this proposal does not automatically leave our solar system with 12 planets." seems to be completely wrong, if the new definition is passed there will immediately be 12 planets! Can someone explain why this sentence is in the article? If no-one can think on a logical reason to keep it, I'll remove it. --Hibernian 14:32, 17 August 2006 (UTC)

I think that the intended meaning was: "Despite what has been claimed in the media, this proposal does not automatically limit our solar system to 12 planets." --Vibragiel 14:51, 17 August 2006 (UTC)

Which makes no sense at all, no definition would ever impose such limit. It's like making a law that says PI is exactly 3.14. Wouter Lievens 12:11, 18 August 2006 (UTC)

That isn't the point. When I wrote that section, I was responding to the media, not to the IAU's definition. Radio, television and internet news sources were reporting that the definition meant our solar system had 12 planets, and leaving it at that. This misinformation needs to be clarified. Serendipodous 12:20, 18 August 2006 (UTC)

Related, on the sentence "Another criticism is that the proposal will lead to too many new planets: while only twelve are currently known to match the new definition, this number is almost certain to increase, and may reach 54 or even more", could this concern not be immediately addresses by adding to the definition an orbit with a limited eccentricity, specifically that it does not come closer to the sun than an inferior (closer) planet. (Yes, I know this would demote Pluto officially, but I'd rather lose one Pluto than gain 43 others!) 72.83.112.110 00:33, 20 August 2006 (UTC)

I'm just waiting for them to discover a KBO that is the size of Mars, and to then hear the anti-new-planets people still arguing that size is irrelevant and it should be classed as a "trans-neptunian object" and a "minor body" simply because of its orbital characteristics. Come on! We need a standard, universal definition of a planet (like the one proposed), which is based on a body's physical charactersitics and not where it is located, and then, no matter how many of said objects we find, we must call them all planets, because that is the nature of science and discovery: finding more stuff in the universe. Limiting planets to orbital inclination and eccentricity is like saying that feathered animal species from North America are called "birds," but those in Asia are "minor birds" or "trans-North-American feathered animals" because there are too many species of bird in North America and we don't want to recognize there being any more of them! If it looks like a planet, then it is a planet, screw the number! And increasing that number to 50 or a hundred or to 200 won't makes planets any less "special," when compared to tens if not hundreds of THOUSANDS of minor bodies--Supersexyspacemonkey 07:01, 20 August 2006 (UTC)

It's difficult to see a KBO the size of Mars not qualifying as a planet under the orbital definition. It would certainly be "by far the largest body in its local population", which would give it planet status. Still, "by far the largest" is beyond vague. I prefer Mike Brown's definition; that a planet should be larger than the combined mass of all bodies in a similar orbit. By that definition, a Mars-sized KBO would NOT be called a planet, but you know what? That doesn't bother me. It would be the ruler of a grand family of worlds within its orbit, and that would be honour enough. Hell, if Titan can't be called a planet because of its orbit, I don't really see what the issue is here. Serendipodous 07:17, 20 August 2006 (UTC)

LOL, and by that last definition, the terrestrial planets themselves, Mars, Earth, Venus, and Mercury would not be planets either. This just gets more and more absurd. The "problem" here is refusing to grant "planet" status to anything else but a completely arbitrary number of previously-discovered bodies and not recognizing the discovery of new large celestial objects as being in the same class. You have no qualm against calling such bodies "worlds," yet "planets" is so offensive. Makes no sense to me. But you are entitled to your opinion. --Supersexyspacemonkey 07:40, 20 August 2006 (UTC)

I don't see how the terrestrials woudn't be planets under that defintion. They are larger than any other objects in a simiar orbit. If you're going to call the terrestrial planets' orbits "similar" you may as well say Saturn's orbit is similar to Jupiter's, or that Pluto is close to the Sun. Heck, all of those statements are true from far enough away. The problem here is that the term "planet" is not scientific. It was invented by seers, sorcerers and priests, not scientists. Astronomy's problems have emerged trying to co-opt it into a workable scientific definition. Any term that intends to include Mercury, Earth, Pluto and Jupiter is already arbitrary enough to be completely meaningless.

Then I also don't see why the hypothetical Mars-sized object "wouldn't" be a planet just because it lies in the Kuiper belt. Or perhaps I misunderstood.

I agree. Whenever you use a definition based on location, you introduce a certain amount of ambiguity. Therefore a "similar orbit" would have to be defined as a certain fraction of the object's semi-major axis. I'd say 20 percent, taking the asteroid belt as precedent. Serendipodous 09:56, 20 August 2006 (UTC)

Yes, I agree 100% that the definition of "planet" is historically non-scientific, it is arbitrary, but it is not meaningless, it is basically "Any object that orbits the sun, and is not a moon, and is far too big for us humans to psychologically feel comfortable equating it to just another one of thousands of space rocks, is a planet." The classical definition is a lot simpler: anything that moves in the sky. But the bald fact is that no matter how "arbitrary" the human notion of "significant size" or "significant importance," or just plain "significance" may be, it's still there, and we have to deal with it. Personally, I wouldn't mind putting an arbitrary diameter cap, a nice round number, on the definition of "planet," since, in reality, we have always held such a distinction but failed to put a number on it. The fact that we don't feel comfortable calling thousands of space rocks "planets," even if they lie in the same general region or have similar orbital properties, proves that size is everything and has long been the real issue, supplanting the simpler classical definition of "wanderer." The fact you object to the idea of "I could throw a beach ball into space and call it a planet" proves that you, like everyone, fundamentally perceive it in the same subjective manner of "significant celestial object" vs. "insignificant/common" celestial object.

What gets me is, I agree with you 100% that the inclusion of gas giants and terrestrial planets is already pretty arbitrary, so arbitrary that the only logical thing remaining to connect these objects to one-another is the fact that they are subjectively considered more "important" than asteroid 1244543. But, your argument takes me to the opposite conclusion. I am uncomfortable pretending like Jupiter and Earth have more in common than Earth and pluto. I would argue, abandone the whole "planet" nomenclature altogether, and leave it to astrologers, or just fess up to what "planet" really means and give it a fixed arbitrary definition. It's not like we don't have plenty of subjective, human-paradigm-defined definitions in science. Many aspects of physics, weather, geology, etc., depend on arbitrary definitions of what is "big" and what is "small," what is "weak" and what is "strong." So what? I would argue that placing 4 so-called "terrestrials" and 4 so-called "gas giants" into a group, wich excludes all other large objects residing in different orbits, makes less sense and is far more arbitrary than inventing a set definition based on physical characteristics and allows the induction of new members. You see, in the end, it might be true that the ancients invented the term planet, but we have been using it in a semi-intuitive way for a long time now, and the commonly understood sense of "big enough to be considered important as opposed to the rest of the rubble" should be respected, because most people think of planets that way.

An interesting idea, but getting rid of "planet" would be next to impossible. It's just too entrenched. Better to come up with a definition and be done with it. Most astronomers don't care about it, and quite frankly, most non-astronomers don't care about it either. The only people who care about this issue are raging pre-teen space nerds trying to protect Pluto. As to your comment on "bigness", my main problem with it is that it would make an already arbitrary term even more arbitrary. Tens of thousands of objects in the asteroid belt won't be planets, but one will, whereas potentially hundreds of objects in the Kuiper belt will be. It just makes more sense to me, aesthetically speaking if for no other reason, to recognise the structure of our solar system as eight solitary objects bisected by two belts. Serendipodous 09:56, 20 August 2006 (UTC)

Frankly, I think that the opposition is being hyperbolic in the extreme. Saying that 50+ planets (or however many they "estimate"), out of how many THOUSANDS of solar system bodies, is "too much," is like saying they should have ended the Period Table with the first 10 elements, and denied "element" status to all the rest, calling them "trans-elemental matter" or "minor chemical elements." Come on, let's not be silly about it. Are we lovers of science or are we ditsy air-heads afraid of "big" lists??? What about extra-solar planets? People psychologically and culturally accept the premise that there are hundreds and thousands of planets in the galaxy, waiting to be discovered. Heck, science fiction deals with this issue regularly. And they are in fact being discovered rapidly. But yet there is some psycho-moral-spiritual-existential issue with discovering more planets in our own solar system? That is cause for some people to go crazy and their heads to explode because of all the little "beachballs" being classified as planets?

Nonsense.

Something is only "special," in the exclusive sense, if it really is exclusive in character, and not if there are others like it and we are only pretending they as if there are not. By calling 8 bodies "planets," and only 8, we are naively pretending as if they are the only celestial bodies large enough to merit the badge of "I'm more than just a rock," when it is untrue. I'll take a hundred "beachball" planets, based on a rational definition that acknowledges new discoveries and is not afraid of our expanding knowledge of the universe, any day, over "We found these 8 first and we're tired of counting so let's stop." Besides, taking issue with the idea of giving a historically arbitrary concept a new and updated, rational, well-defined scientific definition is self-contradictory, because in that case it should not really matter at all, whether there are 8, 9, 53, 0r 200 "plantes," if the fall-back argument is "it's a meaningless term." I cannot think of a more logical definition, based on nature, than mass-created spheroids are planets and everything else is not. I conforms to the popular cultural paradigm of what a "planet" looks like, and nature puts its own cap on the population, ensuring that non-spheroids are far more abundant and less "special" than the beachballs.

Conversely, you could argue that your sphericity definition gives too much distinction to, say, Quaoar over the other KBOs, with which it shares most of its composition, formation, geochemistry etc, simply because it happens to be just large enough to be round, whereas its next door neighbor, which may be almost as big, isn't. Serendipodous 09:56, 20 August 2006 (UTC)

Like I said, I agree with your "planet is arbitrarily defined" argument, but I see that as cause to change the definition, to include all existing planets, plus others. If you meant it sincerely, then there would be no issue against accepting Pluto's 70 year historical status as a planet. But, since there is an emotional "good riddance" attitude towards demoting Pluto, and towards excluding any of those distant "iceballs" no matter how big they are, this proves that the opposition is also trying to impose its own standard definition based on defined properties, only they are biased towards orbital region while people like me are biased towards size. It's all a question of perceived degrees of comfort and what "seems good." Some people can't wrap their heads around 50 planets, while others welcome it and are excited by it, and in the end, majority wins, but one thing is for sure, arguments that the definition is "arbitrary" are extremely hypocritical.

I have no special desire for Pluto to be a planet, I simply want a definition based some rational criterion that's more than just "I'm emotionally attached to these dirt and gas balls but I don't want any damn snowballs to join the club." Despite your previous observation, it make far more sense to include dirtballs, gasballs, and snowballs all into the same club if they have at least some major attribute in common (like size/mass/roundness), than to put the utterly dissimilar dirtballs and gasballs in one club, and then segregate all of the snowballs into their own club no matter what. That's just insane--Supersexyspacemonkey 09:25, 20 August 2006 (UTC)

[Edit: I apologize for the length of this reply, and this is the wrong section for me to be pursuing this debate. I will add no more and respect your position]

What really gets me about the definition isn't the definition itself, it's the fact that they're trying to fudge it. They don't want a solar system suddenly swarming with tiny planets, so they make up this excuse about having to actually SEE the object before they can call it a planet. Why? If you know what an object is made of, and you have a degree in geophysics, you can work out the chemical strength of its structure vs. the force of gravity and determine how massive an object must be to be spherical. Anything beyond that mass limit is a sphere. It can't not be. So this saying that there are "12 planets now; maybe 12 planets later" is, not to put too fine a point on it, bollocks. We know exactly how many planets there are now; at least thirty, probably more. So why not say it?

EDITED: I like being glib, but I'd rather be accurate.Serendipodous 07:49, 20 August 2006 (UTC)

I find the notion that we can already accurately assess the mass of said objects accurately enough to determine whether or not they surpass said limit to be highly disputable. We can barely give rough estimates based on gestimations of albedo, and chemical composition, and you claim we "know" they "must" be spheres and they "can't not be?" That, my friend, is the bullocks, I think. If anything, I would argue that the watch-list is TOO inclusive, and there are many obje cts there whose candidacy is laughable, such as Vesta, and we know a LOT more about Vesta's composition, mass, and geometry, than we know about most of those large KBO's. You can certainly argue that they are fudging on the biggest ones, like Sedna and basically half of the dozen watch-list objects, which they would almost certainly promote to planet status after a short while. You are 100% correct in that. But, to say that we could actually, immediately, fit 50+ objects into the definition is preposterous. We barely know how big they are + or - hundreds of kms. --Supersexyspacemonkey 09:28, 20 August 2006 (UTC)

Well, Mike Brown appears to think he can. I'm not him, nor am I even an astronomer, but if anyone could claim to be an authority on the subject it would be him. Vesta is technically a spheroid, apparently. I don't think we will ever settle the debate about what constitutes "round enough," which for me is just another reason not to use that definition. Serendipodous 09:59, 20 August 2006 (UTC)

Image removal rationale

File:Newplanets.jpg

How the solar system could look if all the potential planets currently under observation were given full planet status

I removed this image because it is inaccurate. Not only is it jpeg, and therfore pixilated, artifacted and limited in resolution; but it states an unusual number of planets - only 1 asteroid and fourty three kuiper belt objects, rather than 4 asteroids and 11 kuiper belt objects (as the article discusses). Also, it groups the first four planets as a confusing ring, and ceres seems to occupy a similar ring. Conclusion; a bad image - Jack (talk) 17:31, 17 August 2006 (UTC)

The image is not the "current" system of 12 planets (which, whatever the outcome of the IAU congress, isn't likely to survive August 25), nor the dozen "candidate planets," but the total number of possible planets that currently exist within our solar system IF the "roundness" definition is adhered to. The solar system is very big; this necessitates a certain amount of compression when trying to describe all of it. Ceres is part of a ring because it is part of a ring; the asteroid belt. The image is of the solar system from the asteroid belt outwards; since no new planets exist between the Sun and the asteroid belt, the terrestrials don't need to be in the image. Serendipodous 17:35, 17 August 2006 (UTC)

Inaccurate? The linked source explains all. I concur with Serendipodous: the image is informative. Please put it back, but use an accurate tagline. mdf 17:52, 17 August 2006 (UTC)

I have no quarrel with the statement "current nine planets", this is accurate, but the way they are depicted is not up to standard. As for the compression issue, a large SVG image would solve that. I feel as a newbie may be checking out this page (as is to be assumed), the other nine planets should be shown accurately as people have come to understand them, if only to provide a simple source of reference. But thats not the main issue - what's up with the numbers?! - Jack (talk) 17:53, 17 August 2006 (UTC)

Please read the direct reference that the image sources. mdf 17:58, 17 August 2006 (UTC)

This image bothers me too. Mike Brown (the image's author) obviously has strong feelings on the issue and is trying to make a point based on his interpretation of how the definition will be applied. Right now the IAU is considering a 12 planet system with an additional 12 candidate planets. Based on those facts, using Mike Brown's interpretation of the new solar system as the one we show to users is rather POV and crystal ball-ish. I support telling people what Mike Brown thinks might happen, but I think showing this image as the only image of a new planetary configuration gives undue weight to his views. Dragons flight 19:03, 17 August 2006 (UTC)

I second the removal of the image. Nick Mks 19:04, 17 August 2006 (UTC)

As far as I know, the IAU is considering the definition of a planet, not a "12 planet system with an additional 12 candidate planets". The current proposal is written in what appears to be plain, simple, English lacking little (if any) wiggle room re: "interpretation". Brown has taken this proposal, combined estimates based on best knowledge and reasonable inferences, and published his results. And far from being what he thinks is the "new planetary configuration", Brown notes that this is merely a reasonable consequence ... and is just the beginning. And heck, he isn't the only one saying this either. I'm not sure what the NPOV has to do with this either, since we aren't talking about whether corn tastes better than peas, but trivial deductions from a clearly written definition. Even if his estimates are off wildly, there are likely tens of thousands of other objects awaiting discovery, and if even .5% of them qualify, we still obtain Brown's conclusions. Can you cite a refutation of his analysis? Honestly, are there other "interpretations" at all? mdf 20:03, 17 August 2006 (UTC)

The IAU press release says 12 now and 12 current candidates: [1]. Dragons flight 20:14, 17 August 2006 (UTC)

Yes. We get that. But is the purpose of objectivity the slavish adherence to one interpretation because it happens to be the official one? Have they explained or justified their decision in keeping the solar system down to a maximum of 24 planets, when quite obviously dozens more would fit the definition they gave? Serendipodous 20:18, 17 August 2006 (UTC)(UTC)

It is not obvious what fits the definition since they don't say what is "round enough" (and propose creating a committee to decide). For all we know, round enough will end up excluding most of the candidate planets. I don't mind mentioning his views, but his view shouldn't be the only image about what a new planetary system looks like. Better no image than a single image representing only one point of view. Dragons flight 20:23, 17 August 2006 (UTC)

I third the removal of the image. Including the image would mean that the article would lose its neutral point of view. It does not show any possible outcome of the ongoing events, and so adds nothing to the article other than bias. Readro 20:15, 17 August 2006 (UTC)

• I think one of the problems with this image has to do with Brown's estimation of how many planets there might be if this resolution is adopted. On his webpage, he uses a figure of 400km as the lower limit for hydrostatic equilibrium, but the IAU definition roughly places the lower limit at 800km, thereby inflating the number of potential planets and rendering this image invalid. Tachyon01 20:32, 17 August 2006 (UTC)

On his website, he points out that 800 km is the approximate diameter for rocky bodies like Ceres to attain hydrostatic equilibrium, but that icy bodies attain this point far more easily than rocky bodies do, and thus they are likely to be round at 400 km. Serendipodous 20:36, 17 August 2006 (UTC)

Plus, you guys are all forgetting the most important point, which is that NO candidates will be promoted until their discs and masses have been observed and measured with sufficient resolution and in sufficient detal to determine, beyond the shadow of a doubt, that they have achieved hydrostatic equilibrium. And that means that MANY of the candidates, even if they are planets, will not be so recognized for several years to come. Thus, the only immediate effect of the proposed definition is a 12-planet solar system, with a small handful of candidates (less than half a dozen) that might be promoted in the near future, and a dozen that will remain on the watch list over a long term period, or indefinitely, or might eventually be removed if they fail to meet criteria.--Supersexyspacemonkey 06:47, 20 August 2006 (UTC)

full draft resolution

Is there a reason why this article does not quote the full text of the IAU's proposed resolution? If this is because of a copyright issue, shouldn't there at least be a prominent link to the entire resolution? --Nebular110 17:48, 17 August 2006 (UTC)

Yes, we're an encyclopedia, not a republisher of original source documents. If the IAU's work is released under a compatible free license, which I doubt, it might be suitable for inclusion on Wikisource. --Cyde Weys 17:53, 17 August 2006 (UTC)

Improper Archive

Cyde threw material he didn't like here into an archive1 which has entries dated later than the earliest entries on this page. Now we're getting our archiving messed up by these people who are going militant over "relevance" in Talk space... Wish I had the time and energy to really fight this trend (I'm very ill). Anyone out there up for it? It would involve identifying editors and admins (like Cyde) who go wayyyy overboard with their notion of what is proper for a Talk page and who have taken to wholesale blowing away of comments that don't match these notions. They need to be stopped administratively. Maybe informal mediation would do it, but you should be prepared for RFC. Anyone? JDG 00:25, 18 August 2006 (UTC)

Well there's no point in having the archive really since it's all irrelevant discussion that should have simply been deleted. Deleting the archive would solve the problem. In any case, I doubt you'll get much support from the admins for using this page as a discussion forum. It was twice as long when it included the irrelevant banter.  -- Run!  07:16, 18 August 2006 (UTC)

Seems to me you are now using this talk page as a discussion forum. And looking over most of the other entries here, I can probably remove about half of them on "irrelevant" grounds by appeal to the standard you are setting up. Will you support me in this action? Rhetorical question of course, since I actually agree with JDG -- but not to the point of taking on an administrator (which, at this point in Wikipedia's development, is as useful as taking legal action against a police officer, even if you have an egregious, undeniable case) -- in that the so-called "irrelevant" discussions can indeed help focus participants. Take, as an example, the current blather over the Mike Brown image of the solar system to be. Arguably, it would make sense, to help other editors understand Brown's point, to dissect the current proposal, explain why it is over-broad and likely to lead to as much use as the 55mph speed limit was on the interstates. Part of this discussion would indeed involve raising and commenting on counter-proposals, why they would be better or worse, and general guidelines about how such proposals can be structured in the first place. Without question, none of this discussion could enter the article directly, but can obviously serve as "mental triggers" for readers to find material which can be included. mdf 12:17, 18 August 2006 (UTC)

Article discussion pages are about the article. It gets archived in a manner that editors can easily view and understand past discussions. If discussion edges into personal exchange, then that sort of discussion can easily go to one user's User page, or to another's. This keeps the article discussion page appropriate to the article, reduces clutter, etc. Terryeo 07:18, 18 August 2006 (UTC)

None of the discussion removed was personal, trollish, inflammatory, or generally detrimental to the community or even Wikipedia as a whole. I have personally removed material from other talk pages that satisfy these conditions. And I mean "removed", not just left little notes about "please don't reply to the following" and other sanctimonious wimp-outs. There is no doubt a high pile of policy and guideline about talk pages. However, the general intent of said wikilaw is to improve the article. If "irrelevant" discussion can do this, then it is, ipso facto, not irrelevant for this purpose. mdf 12:17, 18 August 2006 (UTC)

Criticism of the redefinition

Two of the source cited here are blogs. Strict, literal, obeyance of Official Wikipedia Holy Script says we can take the people who added these sources outside and whack their peepee's with a lead pipe ;-). Arguably, even Brown's reference is in the same situation as it appears to be self-published. I recommend nothing actually be done (since the arguments offered at all sources are sound), but if better sources are known they should be used instead, lest some under-employed admin stomp in, gun drawn. mdf 13:10, 18 August 2006 (UTC)

Yup, I'm aware of that. But I felt it was best to "Ignore all Rules" on this since there isn't anything official yet as this is still at an early stage. The blogs aren't being used to describe anything other than the writers opinions, so turning a blind eye to this violation until better sources arise is my view. Jefffire 13:22, 18 August 2006 (UTC)

Few would contend Brown's authority in this matter. Just like if Hawking writes something new two of the sources are Hawking's texts, it gets recorded. According to the above mentioned WP:RS, Self-published sources: "Exceptions to this may be when a well-known, professional researcher writing within his field of expertise, or a well-known professional journalist, has produced self-published material. In some cases, these may be acceptable as sources, so long as their work has been previously published by credible, third-party publications, and they are writing under their own names, and not a pseudonym." Brown is totally in the clear. McKay 15:57, 18 August 2006 (UTC)

Advantages

It would be cool if 195.137.85.173, or someone else, could document this section's provenance. mdf 15:35, 18 August 2006 (UTC)

News from Space.com

Don't want to put this in yet, because it's pretty small on specifics, but I thought it should be mentioned anyway:

Pluto may get demoted after all Serendipodous 15:54, 18 August 2006 (UTC)

Does anyone have a copy of this "alternate" proposal? Daveharr 17:08, 18 August 2006 (UTC)

If it's true, good riddance! Scientists are so scared of "Public outcries". Come on people. Don't be slaves to old thinking. Just necause PLuto's been a planet for about 75 years doesn't mean it can't be demoted. IF they really are so worried about public perception, call it a "minor planet", "planetoid", "dwarf planet", "microplanet", whatever! --Planetary 22:02, 18 August 2006 (UTC)

I haven't seen from any other sources anything about this 'proposal,' not even a press release from the IAU. This new 'proposal' may not even get before the full IAU assembly for a vote. Tachyon01 00:43, 19 August 2006 (UTC)

Sky and Telescope mentioned it in their article at http://skytonight.com/news/home/3601616.html. The proposed definition is: a planet "is a celestial body that (a) is by far the largest object in its local population, (b) has sufficient mass for its self-gravity to overcome rigid-body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) does not produce energy by any nuclear-fusion mechanism." According to the article, a straw poll indicated greater support for this than the official proposal. It looks like the draft proposal may be revised.

About the criterion c: does this cover the object's whole lifespan (i.e. if it fuses at some phase of its lifespan) or current situation? In the case of former, most massive planets would be around 13 M_Jupiter (no deuterium fusion). In the case of latter, situation becomes laughable; most massive brown dwarfs are about 80 times as massive as Jupiter. Not to mention compact objects (white dwarfs and neutron stars; black holes can't be said to be round in the sense of the definition).--JyriL ^talk 13:13, 19 August 2006 (UTC)

And what is its local population? That could conceivably include the entire solar system. What is Venus's "local population"? It has no satellite.Serendipodous 13:47, 19 August 2006 (UTC)

It also mentioned on New Scientist: http://www.newscientistspace.com/article.ns?id=dn9797&feedId=online-news_rss20 The physics behind the alternate definition takes into account basic planet formation. Planets are formed by mass "clumping" together in a debris disc about a star. The Kuiper Belt is made up of outlying masses that were too far out to be clumped together(in effect these belts are failed planets), hence it's a bunch of similiar objects in a relativiely crowded space over a large area. Same for the asteroid field(althouh it may have been formed differently, for example by a planet being impacted by a large object early in formation). Local area could not include the entire solar system, it is purposely refering systems like the asteroid belt and the Kuiper Belt. Each planet has it's own orbit and angular velocity, but the majority of objects in "local feilds" would have similiar angular velocities(like ring systems of the Gas Giants, each ring has an angualr velocity which is shared by all the particles within the ring). The entire Solar System could not be considered a local field by any stretch of the imagination, it's not crowded enough, the make up of the planets are extremely varied and their angular velocities are different. There would be no confusion over Venus either, it is the largest mass in it's area(since it's the only one) and thus doesn't share an orbit or angualr velocity with a myriad of similiar sized objects. Eccentricned 17:48, 19 August 2006 (UTC)

So, is this worthy of inclusion yet? Serendipodous 18:54, 19 August 2006 (UTC)

I think it should definately be included, as Space.com has published an improved version of the proposal that includes definitions of things such as "local population", etc. I'm assuming from the way the article is written that this proposal will be an option in the August 24 vote. Here's my idea for a section that could be added (Alternate Proposal, below). --69.161.146.61 19:44, 19 August 2006 (UTC)

Looks good. I'll just paste it in, source it and see what happens. Serendipodous 20:46, 19 August 2006 (UTC)

Another thing. Earth has produced energy by a nuclear-fusion mechanism. With luck, we will begin doing so continuously at some point. And Earth's categorization as a planet is significantly older and more important to people than Pluto's. DanielCristofani 20:00, 20 August 2006 (UTC)

Minor quibble but, "Prague in the Czech Republic"?

As opposed to the Prague 27 miles southwest of Walla Walla, Washington? Really I think we can rely on our readers to have at least a vague notion of geography. Serendipodous 22:08, 18 August 2006 (UTC)

Honestly? Often, when I mention Prague, the reaction I get is "Oh, you've been to Czechoslovakia?" And that's the smart ones. Aelffin 22:45, 18 August 2006 (UTC)

"Oh you've from the Soviet Republic of Yugoslavia?" is what I usually get (the smart ones are interested in my proficiency in the Czechoslovakian language), so I say keep the republic in. +Hexagon1 ^(t) 13:28, 21 August 2006 (UTC)

Cheers to that. Or should I say.... Nádraží! :P --Aelffin 17:46, 21 August 2006 (UTC)

• • I think Prague should be enough. There are plenty of cities that have a namesake (Paris, Brussels,London, Berlin,...). We can hyperlink it to the correct city if necessary, but adding 'in ...' seems excessive. We shouldn't cater for the lowest denominator I think.

Hicham,

• • • I think there are only a few cities in the world that are so famous that *everybody* is familiar with them: London, Paris, New York, Washington, Hollywood, Tokyo, Mexico City, Rome, and Moscow. Maybe Berlin, maybe Venice, and maybe Dublin. All others should be given with their country name attached, especially in situations where the country's name has changed in the last couple decades. Then again, it doesn't really matter that much. --Aelffin 15:09, 25 August 2006 (UTC)

PSR B1257+12D

You know, with the proposed redefinition of planet, PSR B1257+12 D is bigger than Ceres, so would be a planet, so this proposal is already having an impact on extrasolar planets. 132.205.45.148 04:26, 19 August 2006 (UTC)

Thought id just put the direct link to the D object here (to save future "its a star" trouble): http://en.wikipedia.org/wiki/PSR_B1257%2B12#PSR_B1257.2B12_D

The mass value for PSR B1257+12 "D" is an upper limit based on the non-detection of gravitational effects... it could easily be much smaller. I'd hold off on claiming planethood. If the object exists, it has been detected via cometary activity (the object's coma affects the transmission of the pulsar's emissions). Chaos syndrome 10:12, 19 August 2006 (UTC)

"...is in orbit around a star, and is neither a star nor a satellite of a planet." It would not qualify because it's a star.

See here: stars can't be planets! Neither can satellites of planets...unless the center of mass of the larger body is above the surface of said body. In which case the satellite would be a planet. But only for a little while, until its orbit changes. Could a star have a brown dwarf orbiting, causing the center of mass to be above the star's surface? Well, yes it could, in which case they'd be two planets in orbit about each other. Or two stars. Ok, damn you all.

And damn the IAU especially for introducing this idiotic definition. Marskell 21:59, 19 August 2006 (UTC)

You do know that PSR 1257+12 D is not a star, right? PSR 1257+12 is a star though. D is an object in orbit around the pulsar, so it is not a planetary satellite. 132.205.93.88 03:36, 20 August 2006 (UTC)

The pulsar couldn't be a planet, but the object orbitting that's smaller than Pluto might be with the new definition. --Patteroast 02:20, 20 August 2006 (UTC)

I wonder how Wolzscan feels about it... 132.205.93.88 03:36, 20 August 2006 (UTC)

I was just being glib and didn't look closelay :). Sorry. Marskell 05:42, 20 August 2006 (UTC)

It's Wolszczan, for your information. :P

Looking through the history of this page, I noticed that Cyde deleted this section once, claiming that PSR B1257+12D is a pulsar, when clearly it is not. Cyde should be more careful in reading the what he's deleting. 70.51.10.212 13:35, 20 August 2006 (UTC)

Oppose Merge

I disagree the idea that this article should be merged with Definition of a planet. Think to the situation in 5 years time. The article "Definition of a planet" is where people would look to find the current agreed definition. The article might mention, in a brief section, the fact that back in 2006 it was changed and formalised and the debate that this created but would not go into much detail. The section woudl then refer people to this article, which would haev all the details of the historical debate, effect of the change and so on. Hence wikipedia should still have two articles.

Does that make sense? AndrewRT - Talk 14:02, 20 August 2006 (UTC)

I agree. This article is about the debate (maybe it could be renamed "2006 planet definition debate"), and the definition page is about the final decision. --Age234 16:58, 20 August 2006 (UTC)

Oppose the merge as well for concuring reasons. Definition of a planet should be an article about what it is then and has been. This article is (and should be) more like a news article on a slow moving story. Jon 18:32, 20 August 2006 (UTC)

Alternative proposal - 50-50 split - not 18-50 split

First para of article says: 18 for the draft proposal, 50 against, then referring to reference 16, "Pluto May Get Demoted After All." Space.com. 18 August, 2006.. But that article says the votes where c:a 50-50, not 18-50!

/spake, Tomas S. Kindahl (tomas.kindahl@comhem.se) 20:30, 20 August 2006 (UTC)...

I didn't see any actual stat of 50-50 in the article, I think that's just a header to give an idea of what was going on. The 18-50 refers to the actual poll: Today, a subgroup of the IAU met to discuss the proposal. A straw vote was held in which only about 18 astronomers favored the proposal, according to Alan Boss, a planet-formation theorist at the Carnegie Institution of Washington. Another 20 or so said it should be reworked. And about 50 favored an alternate proposal put forth by Julio Angel Fernandez, an astronomer from Uruguay. http://www.space.com/scienceastronomy/060818_planet_newprop.html --Age234 14:46, 21 August 2006 (UTC)

Criticism

There's some blatant POV emerging in this article. The draft proposal has both "advantages" and "criticism" subsections, both well sourced. The alternative proposal only has a "criticism" section, completely unsourced, and written in a purely hypothetical manner. It's merely stating someone's anonymous opinions. Where's the "Dr. Mervern Collar from Wales University says X", or "Dr. Milly Vasily from Moscow University says Y"? Serendipodous 19:39, 20 August 2006 (UTC)

This is definately a problem. I took the liberty of adding the "Unreferenced" tag to it. --Age234 03:10, 21 August 2006 (UTC)

1. Nice try, but you are confusing different issues and obfuscating others. The only reason there is no "advantages" section is because nobody has bothered to write it yet. If you have a problem, then go ahead and write one yourself, and quit being so melodramatic.

2. That is the lousiest definition of "POV" I have ever heard. A statement need not be referenced in order to NOT be POV, that is absurd. A criticism can be a logical and hypothetical one, so long as most readers agree that it makes logical sense and makes a valid point (even if they don't agree with it per se). Practically any article you find in Wikipedia contains unreferened criticisms, on both sides of an argument, because they don't require citations to be valid unless they make FACTUAL claims. The ones in the present section do NOT make factual claims, but merely take issue with certain logical consequences of the definition in question.

3. Do not lump all of the statements into one category for your personal convenience. Some are irrefutable a priori statements that stem directly from the facts of the proposed definition, while others are opinions.

4. The section as written was already a blatant advocation of the proposal, and already contained blatant POV, thus necessitating a "criticisms" retort for the sake of achieving overall balance. References alone are insufficient to claim neutrality, if the references are all one-sided, and if opposition obviously exists over a controversial issue. Really, how convenient: if it goes with definition you like, it's ok, but if it criticises it, then it's "POV." As I said before, citation does not eliminate POV, and, conversely, lack of citation alone does not create the same.

5. It is hypocritical to level accusations of "POV" when you are showing such open hostility to the presence of opposing argument within the article. An environment of intellectual honesty tolerates criticism for the sake of clarity and completeness. This whole deal about not providing references is a cheap and vacuous attempt to promote a lop-sided article. Anyone who is more interested in the overall quality of the article than in promoting one argument over the other would welcome opposing views rather play these infantile games.

I also have noted that in discussion you make facetious comments regarding how people take the issue too seriously, yet you yourself express your point of view rather vehemently, at times condescendingly (egg in face), and carry it to the extreme of opposing dissent within the article itself, like now. It would be nice if in the article we could leave such attitudes behind and be more inclusive of both the pros and cons of any contentious definition, be it the preferred one or not, and rather than leveling indignant accusations, we could simply request/conduct research to fill in the citations as needed and as available, as they do in most other well-written articles.

--Supersexyspacemonkey 18:19, 21 August 2006 (UTC)

I feel there's something of the pot calling the kettle black here regarding fecetious comments. I think the two of us have had a constructive debate on the issue so far, and I don't see the need to stoop to personal attacks. The "egg on face" comment referred to me, because I was attempting to move up a paragraph that I felt belonged in a higher section, and ended up accidentally moving it to a lower section. You can call my writing style melodramatic if you want, but that's how I write. If you notice, however I may have disagreed with the fact that the alternate draft had a criticism section but no advantage section, and that the criticism section was unsourced, I didn't remove it or change it, because, however POV I felt it was, I thought it was right. I just wanted sources so that it wouldn't be original research. It actually made me rethink a paragraph I put on the Definition of Planet article months ago that might by original research, even though technically it may be correct. All I was asking for was sources. I wasn't criticising the section. Serendipodous 18:31, 21 August 2006 (UTC)

5. I am removing the present tag and restoring the more appropriate "unreferenced" tage, because the fact of the matter is that nowhere is any factual claim made that requires verification. The present tag is too harsh and implies some sort of deception, while the original tag politely requests references, which is appropriate.

--Supersexyspacemonkey 18:19, 21 August 2006 (UTC)

Actually, there are two "Criticism" sections...

Criticism can be both positive and negative. -- Jordi·✆ 07:45, 21 August 2006 (UTC)

That isn't the point. The point is that a) the section is neither attributed nor sourced and b) it introduces a POV into the article against the alternate draft by not listing its advantages. Serendipodous 08:15, 21 August 2006 (UTC)

Oh, you were referring to the second criticism section. Overlooked it. The first criticism section is referenced. -- Jordi·✆ 08:22, 21 August 2006 (UTC)

Planet Naming Presentation

Anybody get a chance to see the planet naming presentation the IAU webcast this morning? Aelffin 12:05, 22 August 2006 (UTC)

Here's a video of the discussion: [2] (scroll down to bottom). This was a mess, but there were lots of reasonable objections (IMHO) though the chair seemed to be overly defensive and a lot of the comments were too heated I think it's possible to get an idea of how this is going to go. They're holding another discussion session tonight at 5:30 Central Europe Standard Time. Aelffin 13:47, 22 August 2006 (UTC)

Found this link discussing ther goings-on: http://rawstory.com/news/2006/Astronomers_divided_over_planet_def_08222006.html . One interesting thing is that the word "pluton" is now apparently gone from the proposal. Daveharr 17:05, 22 August 2006 (UTC)

And this: http://www.newscientistspace.com/article/dn9817-battle-of-the-planet-definitions-heats-up.html . The author's sense is that the proposal is likely going down to defeat. Daveharr 17:06, 22 August 2006 (UTC)

Yes, "pluton" was a poorly-considered choice. From the mood of the video, it seems like the IAU overstepped their authority in the minds of most astronomers. I've rarely seen scientists so agitated and humorless. I'd give about 2% chance Resolution 5 or 6 will pass. It's too bad; both camps behaved in a rather embarrasing manner. This "War of the World-Definitions" is likely to drag on for a long time--then again, it's just the upset people who speak up, so maybe we've got a sampling problem here. --Aelffin 17:18, 22 August 2006 (UTC)

Woah. I'm watching this right now. I never knew scientists could be so vociferous. Is this going in the article? Serendipodous 18:28, 22 August 2006 (UTC)

WOW this is like Science CSPAN...Love it!!!Dr. Guillermo A. Sanz-Berney 21:02, 22 August 2006 (UTC)

"...like Science CSPAN" And the Plebians did look upon this phrase; and some did shiver with glee, whilst others did shiver with fear. Aelffin 13:57, 23 August 2006 (UTC)

A good watch, and a unique event to behold. Will add something to the article. --Ross UK 03:39, 23 August 2006 (UTC)

Latest Draft

New Scientist (http://www.newscientistspace.com/article/dn9818-astronomers-lean-toward-eight-planets.html) says there is a new official draft. Sky & Telescope reports at http://skytonight.com/news/home/3707031.html. The text of the draft is:

"A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid-body forces so that it assumes a hydrostatic-equilibrium (nearly round) shape, and (b) is the dominant object in its local population zone, and (c) is in orbit around the Sun."

This kicks out Pluto, leaving it and Ceres as "dwarf-planets" (with the hyphen), although the New Scientist article indicates that this term may end up being something like "planetoid". This is getting very close to the alternate proposal, other than terminology differences. No mention of the double-planet rule in the articles, but I'd guess Charon can't be a planet if Pluto isn't... :-)

But isn't Ceres the "dominant object in its local population zone" (the dominant asteroid in the asteroid belt)? I hope they will clarify the notions of "dominant" and "local population zone". Also, it would seem more logical to state the "orbit around the Sun" criterion before the "local population zone" criterion, which is linked to the notion of "orbit". Wikipetzi 07:42, 23 August 2006 (UTC)

My guess is that dominance is basically defined as an object that clears all the minor debris out of its orbit, which would mean we have 8 planets and that's it, period. Aelffin 13:54, 23 August 2006 (UTC)

Also, the draft apparently specifically states that it only applies to this solar system, and that classifying objects in other systems will wait for a future day.

The draft will undergo further refinement before Thursday, so it will likely change. Both reports are calling this "The Day We Lost Pluto". :-)

I'm not sure when this should go into the article. It's a moving target, but it should probably go in soon anyway. Daveharr 01:07, 23 August 2006 (UTC)

The documentation is more than strong enough. A new section noting this proposal and the basic consequences should be inserted ASAP. --EMS | Talk 03:26, 23 August 2006 (UTC)

Okay so Pluto is removed, but are any new planets going to be added, or are we going to be stuck with 8? Dionyseus 03:40, 23 August 2006 (UTC)

We'd be left with 8 planets, just like God intended ;) Robert Brockway 03:58, 23 August 2006 (UTC)

If a trans-Neptunian Object is found that is larger than Mercury it immediately become planet by this proposal because it would be the dominant object in its local population zone. The reason for Mercury is that it would become the smallest planet. They also need to define "local population zone" because if the trans-Neptunian region is a "local population zone" then would it not make sense that the largest object should be classified as a planet. The problem that arises is that if astronomers find an object that is bigger than above mentioned object would they then classify that object as a planet and demote the former. In my opinion the first proposal has the least number of problems with it. -- Daniel Schibuk 13:41, 23 August 2006 (UTC)

Well, I think that the proposal calls for only objects that dominate their population "by far". Though this is left undefined, I think it's safe to say that if there were any such object in the Kuiper Belt, we'd have discovered it already. In effect, the new revisions lock us into having 8 planets. --Aelffin 13:49, 23 August 2006 (UTC)

There is no mention of "by far" in the wording of the proposal so either they reword it or they define what they mean by "dominant". You have to remember that the trans-Neptunian region includes the Oort Cloud region as well as the Scattered Disc region. There are objects in that region that have not been discovered or officially announced and other objects that we have very little data about. It is conceivable that there objects in the trans-Neptunian region larger than Mercury. --Daniel Schibuk 14:12, 23 August 2006 (UTC)

Sorry, I was thinking of the alternative proposal. Still the feeling I got from both proposals was that the eight uncontroversial planets would most likely be the limit. I mean, whatever they decide upon for the definition of "dominant", I doubt it will be simply the biggest mass in the population. I really don't think this is the way they're using the term. I think they mean "dominant" in the sense that the body dominates all of the properties, including the orbital mechanics and configuration, of the entire local population. The eight classical planets clearly dominate in this sense; one cannot speak significantly of the Trojan asteroids, for example, without Jupiter as a reference point. One can, however, treat main belt asteroids and KBO's as independant of the influence of Ceres and Pluto (or UB313). If you take away the largest body in these populations, the populations will still retain their shared orbital features. If you take away Jupiter or the Earth, then the configuration of their local populations would have to alter radically. I could be wrong, but I think it's safe to say that any object sufficiently massive to dominate the Kuiper Belt in this sense will have already been discovered. Of course, I could be wrong. --Aelffin 18:02, 23 August 2006 (UTC)

When you refer to Kuiper Belt do you include the Oort Cloud and Scattered Disc because they have found 2000 CR105 and 90377 Sedna in those regions so it is possible that astronomers could still discover massive objects in those regions of the solar system. --Daniel Schibuk 19:36, 23 August 2006 (UTC)

No, the Oort Cloud and the Scattered Disc are seperate populations, but I would expect the same ideas to apply. If there were a body big enough to "dominate" those populations in the sense that is intended by the IAU, we'd have discovered it by now. Of course, I'll admit ignorance here. I don't know how big an object must be to dominate those populations, and I don't know what the maximum currently-observable size would be for an object orbiting at that distance. Anybody care to speculate? All I know is that the alternate proposal, which would have defined things in this way, was also referred to at the IAU discussion as the "Eight Planets" proposal. I inferred the rest from that. --Aelffin 02:46, 24 August 2006 (UTC)

Good to hear. 8 planets, with Mercury being smallest, and Neptune farthest... all of the time. WHy so many people have a problem with it I don't know.

I don't have a problem with it per se, but I was looking forward to hundreds of "new" planets from a pedagogical point of view. After all, this re:definition won't affect astronomers too much since they're more likely to refer to a body by a more specific term than "planet" (see cubewano, Centaur, Plutino, Hot Jupiter, etc). The people that will be effected are teachers, who will have to (thankfully) change their paradigm of astronomy education. The real definition for the term planet is "those nine things you have to teach in astronomy class". If we say there are hundreds of planets, schools will feel obliged to either teach them all or (better) teach a systematics approach to astronomy, which is long overdue. If, on the other hand, we say there are actually only eight planets, then they'll all just say, "Great, we don't have to teach about Pluto any more." I realize this isn't a scientific consideration, but primary education is where it all starts. --Aelffin 19:03, 23 August 2006 (UTC)

When it comes to Kuiper Belt/Oort Cloud Objects... there is still plenty of chance for large body... take for example Sedna, it Aphelion is nearly 1000AU and its orbit takes 12000years to complete. If it was near Aphelion we wouldnt have discovered it, if a larger body is at that range now... we probably wont either

Yes, but "large body" and "dominant" are not the same thing. Like I said, I think that it wouldn't be considered a planet under the final draft resolution unless it actually dominated teh orbital mechanics of the Kuiper Belt. If I'm not mistaken, if any such object existed, it would be obvious from its effects on the surrounding bodies by now. So, Sedna's big (but not as big as UB313), but not nearly big enough to clear out its orbit. (by the way, you should sign your posts) --Aelffin 01:26, 24 August 2006 (UTC)

The resolution states that a planet must be a "celestial body". According to Wiktionary, a "celestial body" is "an astronomical object that is visible in the sky". Is Neptune a planet? Only with a good telescope. O.K., but even with a very good telescope, you won't find Earth in the sky. Therefore Earth will no more be a planet. Won't somebody please think of the children? Wikipetzi 01:47, 24 August 2006 (UTC)

See the discussion below. --Aelffin 02:40, 24 August 2006 (UTC)

In the wikipedia articles for 2000 CR105 and 90377 Sedna they say that astronomers do not know why those objects have such highly eccentric orbits. It even goes on to say(exact wording from 2000 CR105 article): One theory states that they were pulled from their original positions by a passing star or a very distant and undiscovered giant planet. If this planet side is true then we would therefore have to add this gaint object as a planet it found to orbit the Sun. This therefore says that there is a possibility of large planets in the outer reaches of the solar system. --Daniel Schibuk 12:19, 24 August 2006 (UTC)

The article 2000 CR105 is not using the IAU's proposed definition of planet, and it is unclear whether this hypothetical "giant body" would be classified as a planet according to the new definition. I'm not saying it's not possible; I just get the feeling from the IAU discussions that nobody expects to find any more bodies large enough to fit the current definition (which I heard has passed, sans "classical"). So, it looks like Pluto's out. --Aelffin 13:52, 24 August 2006 (UTC)

general minima

The roundness factor generally results in the need for a mass atleast 5 x 10²⁰ kg, or diameter atleast 800 km in size.

Do Nature's sums work? 132.205.93.195 04:26, 23 August 2006 (UTC)

It depends on the composition and and structure of the object in question... there is no magic number... just a range where objects tend to become round

The IAU seems to be defining sub-stellar objects by criteria that have little to do with what they are. The spherical component is perhaps a valid one, though a very small amount of water would be spherical by surface tension and then freeze. But the other two components are vaguaries, which is asking for trouble down the road.

Perhaps we'd be better with gas giants, rocky planets, planetoids and planetismals. Even that isn't perfect, as 'super-earth's' just keep getting deeper atmospheres until you are at the Uranus and Neptune level. The division between planet and planetoid, both being spherical, is purely arbitrary. A planetismal would be the small objects that are not spherical, whether rocky or ice. If we go by having an atmosphere for planet versus planetoid, then we loose Mercury.

It does seem sensible that we should define objects by what they -are-, and discuss separately their orbits. The Moon, the Gallilean moons, Titan and Triton (and possibly several Saturnian spherical moons) would be planets and planetoids, but are sattelites, nonetheless.

We need non-arbitrary boundary criteria based upon what the SSO -is-.

I contributed to a paper submitted to the IAU back in '96 on the SSOs. sschaper_iowa@yahoo.com

Why aren't orbital dynamics valid criteria for defining planethood? Though I agree with you; ideally, we should have a nomenclature for orbital mechanics and a separate nomenclature for composition and/or gravitational effects, as you say. So, a gravitational spheroid that orbits a center of mass located within a larger body would be a "sattelite planemo" and an irregularly shaped one would be an "asteroidal sattelite" perhaps, and one that orbited a star would be a "planetary planemo" or a "sub-planetary asteroid" or something like that. I guess the debate is over which criteria should take precedence. --Aelffin 01:35, 24 August 2006 (UTC)

The final resolution text

is out: Last page of Meeting newsletter No.9. My bet: 5A yes, 5B no, 6A yes, 6B ?(50/50) --Scan 21:04, 23 August 2006 (UTC)

Agreed. 5B is a sneaky way of getting back to the original resolution, it seems to me. Daveharr 22:20, 23 August 2006 (UTC)

FWIW, I think they'll go for 6B. I think 5B is the best attempt at compromise we have yet seen. --Ross UK 00:38, 24 August 2006 (UTC)

From a grammar point of view, the name "dwarf planet" implies a class of objects which is a subset of the class "planet", but the classes defined in 5A1 ("planets") and 5A2 ("dwarf planets") are mutually exclusive according to criterion (c). What a mess: it's like saying that "small dogs" are not "dogs". Resolution 5B tries to solve the problem with the two names "classical planet" and "dwarf planet" but then we would have "classical dogs" and "small dogs" and still no definition for "dog"... I would rather have the names "planet" for 5A1 and "planetoid" for 5A2. That's clear, that's it, that's all. Wikipetzi 00:53, 24 August 2006 (UTC)

Back to the article - the current text says that 5B would result in classical planets and dwarf planets as subsets of planets, and this seems to be incorrect to me, as you have noted - 5B would not provide any proposal for "planet" at all. Am I misinterpreting the article or does this need to be changed? Daveharr 00:56, 24 August 2006 (UTC)

I agree that it's a bit of a mess, with "dwarf planets" exluded from the definition of 'planets'. What I am saying on 5B is that the definition of 'planets' would be the sum of two mutually exclusive parts (paragraphs (1) and (2)) instead of a single, explicit statement. They are not, however, 'subsets'. Without 5B 'planets' would be defined solely by (1), and (2) would add a "consolation prize". It is this upon which the debate will focus. --Ross UK 01:14, 24 August 2006 (UTC)

Ah, but 5B does not explicitly state that "planets=classical planets+dwarf planets". It actually leaves "planet" formally undefined, which seems to miss the point of the exercise. Daveharr 01:19, 24 August 2006 (UTC)

This is true, there could be any number of different types of planet, and 5B does not set out an exhaustive definition. This ambiguity is necessary to such a compromise. --Ross UK 02:22, 24 August 2006 (UTC)

If you read the comments titled "250 Words Against" which is directly below the final draft resolution in the IAU newsletter linked above, the point is addressed. The detractors oppose the new definition because it implicitly defines "planets" as "classical planets+dwarf planets". It's not explicit, but the other comments, titled "250 Words For" do spell out the fact that Pluto is a planet, but...only a dwarf planet. Essentially, the new definition gives 12 to 50 planets and counting, but all the new objects will merely be "dwarf planets". I think that's a good compromise. But then again, I'm not an astrophysicist. --Aelffin 01:43, 24 August 2006 (UTC)

Hear, hear. It steers a course between the two camps, bringing in dynamics which were previously neglected and honouring Pluto et al with their proper status. --Ross UK 02:22, 24 August 2006 (UTC)

With 5A alone, the situation would be not that much different from now, where we have "planets" and "minor planets" (which are also not planets), just termed differently and given a definition based on physics. That makes it very attractive, as it defines the things we started with to define without having too much changed. The best definition would express what everyone agrees on anyway on a physical basis. This, however, is obviously not possible. 5A results in one object at the upper end resorted and a cutoff defined for the lower end. If the 5B suggestion would have been to add "major" instead of "classical", it would have had much higher chances IMO. So, with "classical" it sounds a bit like "that's the old stuff, and here comes what we really believe". --Scan 01:48, 24 August 2006 (UTC)

I agree that 'major' would have been a better choice. --Ross UK 02:22, 24 August 2006 (UTC)

The final resolution states that a planet must be a "celestial body". According to Wiktionary, a "celestial body" is "an astronomical object that is visible in the sky". Is Neptune a planet? Only with a good telescope. O.K., but even with a very good telescope, you won't find Earth in the sky. Therefore Earth will no more be a planet. Won't somebody please think of the children? Wikipetzi 01:53, 24 August 2006 (UTC)

That's actually not the definition an astronomer would have in mind. For astronomy, a celestial body is the fundamental subject of celestial mechanics. Therefore, the earth is a celstial body. A binary star is an astronomical object, but not celestial body. It is build of two of them. --Scan 02:06, 24 August 2006 (UTC)

Huh? A binary star is not subject to celestial mechanics? I must admit ignorance here. Aelffin 02:13, 24 August 2006 (UTC)

I meant the components are considered the celestial bodies of that system, indeed not the system itself (unless you go into galaxy dynamics, of course, where you can treat the whole system as pointlike). --Scan 02:16, 24 August 2006 (UTC) PS: if you like, you can consider celestial bodies as the "atoms" of celestial mechanics.

I see. Or, if you bump it up to galactic dynamics, binaries might be "molecules". --Aelffin 02:38, 24 August 2006 (UTC)

Just to poke a bit of fun... what would that make galaxies? :P

Mixtures :)

Introductory text

Is the introductory text quoted in the "final draft", namely

The IAU...resolves that planets and other bodies in our Solar System be defined into three distinct categories in the following way:

present in the final definition (or the text accompanying the final definition)? I would imagine it or something like it must be, but it's not shown here. It's critical, though, because it specifies that the definition applies only our own solar system.

The footnote in the version passed contains "The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune" - which means, yes, this ruling only applies to our own solar system (but will probably be treated as precedent in twenty years when we find something small enough elsewhere). Shimgray | talk | 16:47, 24 August 2006 (UTC)

It's already told in about (seems in the "22 Aug" sub-topic) that astronomers agree that this redefinition only concerns solar system objects.210.17.128.146 05:58, 25 August 2006 (UTC)

The merge tag

I don't see how the tag is hurting anyone and that we need to foreclose discussion. The two articles are 65k between them and given that this one is not summary style and that there is 5 to 10 over-lapping k it still seems to me we should leave the question open. Marskell 08:32, 24 August 2006 (UTC)

It seems fairly uncontroversial that the two be merged after the dicision is made, which I understand to be happening soon. Jefffire 08:48, 24 August 2006 (UTC)

There is marked trend in the poll from "merge" to "don't merge or at least wait and reconsider". The current poll does not reflect a consensus on the current articles, nor can it reach one as long as so many old votes remain. Whatever you think of the reasons behind this shift, we should respect it and table the question. Melchoir 08:56, 24 August 2006 (UTC)

I agree with Melchoir. Dionyseus 08:57, 24 August 2006 (UTC)

you propose to simply ignore many people opinions because they are old? Why not simply start a new poll after the conference is over? Jefffire 08:58, 24 August 2006 (UTC)

Yes, wait and reconsider. So how does the tag hurt in the meantime? I'm assuming this is going back to the main page after the decision. We should invite people stopping by to leave a comment. And Jefffire is right, you can't toss out two dozen opinions by diktat. Marskell 09:00, 24 August 2006 (UTC)

I propose to ignore everyone's opinions because they are too unstable for a consensus to be reached, let alone an informed consensus on the ultimate fate of the articles. We should simply start a new poll after the conference is over. In fact, we should wait a few days after that, and wait for the wild fluctuations in content to settle down. To emphasize that action is not currently under formal consideration, and that new discussions belong in a separate section, we should take down the current tag and put up a new one later. Melchoir 09:09, 24 August 2006 (UTC)

Not "under formal consideration" strikes me as wiki-lawyering a touch. The page is getting hits and the tag may invite newcomers to the talk page. I don't see the harm.

That said, I was concerned the removal was "case closed, no merge." If, rather, it's "let's wait", then I'm less concerned. I would like at some point to attempt a merge in user space to see how it feels but that would be a waste of time if the question is already being cut-off. Marskell 09:14, 24 August 2006 (UTC)

The harm I envision is this: if the tag stays up, it invites a continuous stream of votes. This would make it impossible to impartially choose a cutoff and open a second discussion. I'd like to remove the tag and write at the bottom of the discussion: This poll did not reach a consensus. Until a new poll opens, feel free to continue discussing the merits of a merge, but any votes here will not be counted. Okay? Melchoir 09:25, 24 August 2006 (UTC)

Why don't you write that and leave the tag up, i.e. there is still an on-going merge discussion and it is noted on the page, we're just not polling on it at the moment? Marskell 09:29, 24 August 2006 (UTC)

That might work, too. Let's try it. Melchoir 09:39, 24 August 2006 (UTC)

Personally, I feel that this page should document the last couple of weeks of debate, and the details of the exact proposals. Definition of planet can simply quote the definition that was passed, and point to this page for further details. Bluap 14:26, 24 August 2006 (UTC)

If that's the case, then this article needs to be renamed to something like "2006 soap opera at the IAU re: definition of planet". mdf 14:40, 24 August 2006 (UTC)

I think it would be more proper to remove the merge tags, and if submitting for consideration in a few days, reattach the tags. zoney ♣ talk 14:28, 24 August 2006 (UTC)

Well, I just don't get it. The day the page is most likely to get hits is the day we shut down discussion.

If anything Definition of Planet should be renamed, perhaps Historical Definition(s) of Planet. If this sub-article is going to co-opt what ought to be its subject matter, then its current title is a misnomer. Marskell 17:24, 24 August 2006 (UTC)

The notice on the poll does not shut down discussion; it explicitly invites discussion while honestly stating the hard truth that the first poll didn't work.

We do not yet know what impact the IAU will have on either popular or scientific usage. Renaming the articles as you suggest or allowing this article to co-opt the topic of the other amounts to crystal balling. Melchoir 19:42, 24 August 2006 (UTC)

Citation for final proposal

The listed final proposal is uncited. Serendipodous 09:43, 24 August 2006 (UTC)

The cite's at the end of the preceding text. Shimgray | talk | 13:34, 24 August 2006 (UTC)

From the IAU webcast

...5A has been approved (yes, I know this is unverifiable) Shimgray | talk | 13:23, 24 August 2006 (UTC)

5A has been announced by the Associated Press as being passed thus stripping Pluto of its planetary status. [3] --Daniel Schibuk 13:44, 24 August 2006 (UTC)

So how many voted for and against 5A?

5B is defeated. 6A and B are currently bickering over where to put a colon, they're as bad as us. Shimgray | talk | 13:49, 24 August 2006 (UTC)

So how many voted for and against 5B?

5A was taken overwhelmingly on a show of hands; there was only scattered opposition and no count was needed. 5B had the support votes taken at ninety-something; it was felt unnecessary to count the oppose votes after that, since they were guaranteed to be by far the majority and time was pressing on. Shimgray | talk | 18:19, 24 August 2006 (UTC)

lol, the amount of grammar fighting is quite stupid!

6A passed, 237-157. Shimgray | talk | 14:01, 24 August 2006 (UTC)

6B looks like it's failed, 183-186? Shimgray | talk | 14:10, 24 August 2006 (UTC)

The 6B decision will go into a committee. Shimgray | talk | 14:14, 24 August 2006 (UTC)

Er, so, the Pluto decision is final. And what about the Charon, Seres and UBXenawhatsherface? doktorb _words^deeds 14:22, 24 August 2006 (UTC)

According to the definitions, they are classed as Dwarf Planets. Bluap 14:24, 24 August 2006 (UTC)

No - the definition merely said what the rules are. It's not clear offhand if Charon is covered, but Ceres and UB313 are probably in. I suspect a formal ruling will be issued soon. Shimgray | talk | 14:26, 24 August 2006 (UTC)

Charon doesn't become a dwarf planet, it is just a moon (by this new definition anyway). --Cyde Weys 14:34, 24 August 2006 (UTC)

I believe the new definitions only classify the objects whose primary is the sun. The rest would be satellites. --Aelffin 14:49, 24 August 2006 (UTC)

Yes, but Charon is not a satellite -- Charon and Pluto orbit a common centre, which in turn orbits the sun... —Nightstallion (?) 05:43, 25 August 2006 (UTC)

Well, it depends on your definition of satellite. Remember, *no* object truly orbits another object. Any object in a two-body system orbits the system's barycenter. Always. Period. This is true of the Earth and Moon, the Earth and Sun, a speck of dust and a black hole, etc. No matter what their mass difference, the smaller mass shifts the barycenter somewhat. So, the question is not whether Charon orbits a barycenter, but whether we want to differentiate between satellites and other objects based on the location of the barycenter or based on some other criterion. The IAU did not rule on this matter, but the idea they floated was exactly what you tried to explain: if the barycenter is outside of the primary, then it's not a satellite. The only problem I see with this is that certain systems with highly elliptical orbits might have a barycenter that shifts far enough to mean the smaller object is a satellite part of the time but not all of the time. Obviously, this would be an odd definition, but I think such cases would be rare enough to warrant their own terminology, thus leaving the IAU's suggestion as reasonable for any system it would be applied to. --Aelffin 14:53, 25 August 2006 (UTC)

Some references

Wow, I didn't expect this to make front page news everywhere, but it did. Here are some articles that could go into the article as references:

• [4]
• [5]
• [6]

By the way, I think this has now established enough notability, and there's enough we can say on the subject, that it shouldn't be merged into Definition of planet. --Cyde Weys 14:32, 24 August 2006 (UTC)

Is it the soap opera that is notable or is it the definition itself? If the former, then this article needs to be renamed. If the latter, then this article needs to be merged. mdf 14:42, 24 August 2006 (UTC)

I would say that both are notable, and both have generated enough verifiable information to justify a separate article. I think that the article should be renamed to something more precise and neutral, like IAU definition of planet, mainly because it is difficult to judge whether or not the IAU will succeed in changing the meaning of "planet" in modern use. Melchoir 15:38, 24 August 2006 (UTC)

Personal idea for planet definition has been relocated to my homepage.

Comments are welcome. — Rickyrab | Talk 14:41, 24 August 2006 (UTC)

My personal idea: Rename "Uranus" to "Pluto"! Kids are happy because Pluto's still a planet and we'll finally be rid of that sticky Uranus issue. --Aelffin 16:03, 24 August 2006 (UTC)Aelffin 16:00, 24 August 2006 (UTC)

Date format

Shouldn't this article be in International date (dd/mm/yyyy) format? Rather than American (mm/dd/yyyy)? A little bit of a nitpick with the article in so much flux, but right now the majority of the dates are in American, but there are a few internaional formats scattered around. Figured it'd be a good idea to get the format nailed down now to avoid a mixing of formats for readers that don't have preferences set yet. --Bobblehead 14:56, 24 August 2006 (UTC)

The subject is neither American nor British, so both notations are considered acceptable. Not changing it is the most accepted way to go in these cases. Edits just to change date format are not appreciated by some editors and might lead to an unwanted series of reversions. Everybody understands what date is meant, so why bother... Cpt. Morgan (Reinoutr) 15:19, 24 August 2006 (UTC)

"cleared the neighbourhood"

I would add the term "cleared the neighbourhood" to the sentence "The exact scientific or mathematical definition of "nearly round" and "the neighbourhood around [a body's] orbit" were not explained.". What objects need to be cleared off/collected? In earth's neighborhood there are its moon, several Near-Earth objects of different sizes and other particles and molecules. Is there a minimum size, amount or aggegated mass that divide it in this area from ceres? --RMeier 15:31, 24 August 2006 (UTC)

Ceres is about 1/3 of the mass of its orbital neighbourhood, whereas Earth is about 98.75%; there's a big difference between "largest" and "overwhelming". Also, all objects in Earth's neighbourhood have their orbits "dominated" by Earth, whereas Ceres doesn't exert that kind of gravitational influence over the asteroid belt.

They stated a committee would be formed to decide boundaries later; these are just the general principles. Shimgray | talk | 16:20, 24 August 2006 (UTC)

The latter sentence answers my questions: There is a boundary to be defined, and this is not yet part of the resolution. Thus the term "cleared" is also not yet explained and should be in the list along with "nearly round" and "neighbourhood around its body". --RMeier 16:28, 24 August 2006 (UTC)

I think I misphrased that. The boundaries have been laid down - the committee will decide which side any future objects fall on a case-by-case basis, rather than defining the exact boundaries and waiting to see what comes along. I suspect the first order of business will be to explicitly confirm Ceres etc.

"nearly round" is defined - it's "(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape" - in the Resolution, so we don't need to list that. "nearly round" is just a layman's summary of what HE means.

"Cleared" is very close to "orbital dominance", suggested before, but we don't have an article on that - I don't know if it's an accepted concept already or not. Shimgray | talk | 16:31, 24 August 2006 (UTC)

The notions of "clearing the neighbourhood" or "planet dominance" are well explained and quantified in this article by Steven Soter: What is a planet?. I've read somewhere this week (it was probably on www.space.com) that the inclusion of that concept in the definition of planet was inspired by that article, among others. Maybe there should be a link to that article. Wikipetzi 18:32, 24 August 2006 (UTC)

I'd go beyond that and strongly suggest inclusion of Figure 1 of that paper in one of these articles, as it clearly shows why the IAU definition is dynamically sound. mdf 14:07, 25 August 2006 (UTC)

Why doesn't it say that planets cannot be satelites?

In the final definition of a planet, it doesn't talk about not being a satelite. It does so with dwarf planets though.

Ofcourse there is the "has cleared it's neighbourhood", but this seems a bit vague to be actually usable, unless they define this. My question is why add the 'isn't a satelite' just for dwarf planets? Is this really necessary or should it be only 'clearing the neighbourhood' as a criterium? [User:Hichamvanborm]

The definition states they have to orbit the sun. No satellites, therefore. --Scan 16:08, 24 August 2006 (UTC)

Wild stab is because of situations similar to Pluto and Charon's relationship. If they didn't add "is not a satellite" then one might argue that neither is a dwarf planet because they orbit a point in space between the two and that "point in space" is actually what orbits the sun.--Bobblehead 16:15, 24 August 2006 (UTC)

Ok, the sun part explains soemthing, but dwarf planets have to orbit the sun as well, so why add the "is not a satellite" there? Does this mean that they mean to exclude all double (or more complicated) "planets" from being planets? What if Jupiter and Saturn orbited around a point somewhere between them and then orbited the sun together? They would stop being planets suddenly? The need to compromise seems to make for a crappy definition... [User:Hichamvanborm]

Good point. It would appear my wild stab missed its mark. That's the only explanation I could come up with that would require the extra redundancy of 'is not a satellite'. Last I checked the definition for satellite was that it orbitted around something other than a star. Unless they mean an artificial satellite as those can be round, orbit a sun, and not clear out their orbit.;) --Bobblehead 17:03, 24 August 2006 (UTC)

According to the final definition, is the Pluto-Charon system a binary dwarf planet system (orbiting around a common outside barycenter) or rather a dwarf planet (Pluto) with a satellite (Charon)? Wikipetzi 18:44, 24 August 2006 (UTC)

That one's up in the air. As I see it, Charon is not a satellite; at the GA session, however, it was stated that Charon would be a satellite of a dwarf planet. --Ross UK 22:00, 24 August 2006 (UTC)

Either way, I don't really care, but according to Wikipedia's definition of a satellite, "the general criterion for an object to be a satellite is that the center of mass of the two objects is inside the primary object" and Charon would then, not qualifying as a satellite, rather be a dwarf planet in a binary system, which contradicts IAU's final statement. The problem of IAU's adopted definition of "dwarf planet" is that it uses the word "satellite" without defining it. Wikipetzi 23:41, 24 August 2006 (UTC)

It's not just planets

The IAU also created the overall term "small solar system body", to replace "minor planet" et. al. - I've created a very brief stub. Contributions welcome. Shimgray | talk | 16:39, 24 August 2006 (UTC)

Translation

I am going to translate this to spanish so we have other points of view in the discussion.Dr. Guillermo A. Sanz-Berney 17:09, 24 August 2006 (UTC)

Strange

Strange that they would create this new definition without defining the terms used in the definition, such as "nearly round" and "neighbourhood". The word "planet" had an ambiguous definition and now it still does. I guess we haven't accomplished much even after all those discussions. 206.47.141.21 17:19, 24 August 2006 (UTC)

Nearly round is defined by the words in front of it - it's added simply as a laymans term. "Neigbourhood" is somewhat unclear, but I get the gist of what it means - really, these are as much guidelines for a future committee as they are hard-and-fast here-and-now rules. We don't need to define the borderline right now. Shimgray | talk | 17:21, 24 August 2006 (UTC)

It's not ambiguous about any of the objects we currently know of that anyone cares about. There may be some edge conditions down at the lower bounds of dwarf planet ... but that doesn't particularly matter. --Cyde Weys 17:27, 24 August 2006 (UTC)

Tell 4 Vesta it doesn't particularly matter :). Marskell 17:31, 24 August 2006 (UTC)

Cruithne et al, Trojans, TNOs... Don't these all invalidate the Earth, Jupiter and Neptune from the list of planets? The IAU fudged up in my opinion. --Walshicus

Not at all. "Sweeped up other objects in its orbit" refers to long ago when the planets were forming. Had Cruithne and the Trojan point asteroids been around when the planets were forming they would have become part of the planets. When the planets formed they did sweep up everything in their orbit. --Cyde Weys 17:33, 24 August 2006 (UTC)

Does the definition explicitly say that? Does it even matter given the wording? C'mon, they replaced one arbitrary method with another arbitrary method of determining planethood... This would mean that two hypothetical objects of 2 Earth masses each, both sharing an orbit at a distance of 20AU would not be considered planets, and that's plain silly. --Walshicus

No, but the idea has been pretty clear among astronomers for a long time; it's just unfortunate the public doesn't keep up with these things so when scientists tell them there is no Santa, they are taken unaware. As to your hypothetical double planet scenario, I don't see why they wouldn't both fit the current definition of planets. --Aelffin 18:36, 24 August 2006 (UTC)

No, they wouldn't fit the definition. They'd be unexpectedly large KBOs, but they certainly wouldn't be planets, as they wouldn't be nearly large enough to have swept their orbits (and judging by the number of stuff out in the Kuiper Belt we know that there are no planets beyond Neptune). Also, it isn't possible that there are 2 Earth mass planets out at 20AU anyway. You do realize that 20AU is inside the orbit of Neptune? We would have spotted them a century ago if they did exist. --Cyde Weys 19:47, 24 August 2006 (UTC)

Which is precisely why I used the term "hypothetical". The definition of a planet isn't something limited in scope to the to the vacinity of Sol. --Walshicus

They'd fit the definition just fine. Any two hypothetical bodies the size of *Earth* would certainly have cleared their neighborhood, would certainly be spherical, and as long as the barycenter was in orbit around the Sun, then the bodies for all intents and purposes orbit the sun. They would therefore fit all three of the IAU's criteria. Obviously no such bodies exist, but it's still an enlightening question to examine how such a hypothetical system would be treated under the definition. The only open question is whether we'd use some equivalent of the term "double planet" or if we'd call it "a planet and its satellite". If they're precicely the same mass, then there would be no way to differentiate between the planet and the satellite, so they'd either be a double planet, co-orbiting planets, or maybe mutual satellites or something along these lines. If there's a significant mass difference, then one might be able to argue the planet/satellite distinction. --Aelffin 14:41, 25 August 2006 (UTC)

Nevermind, it sounds like affirmative action, keep abreast of new laws as ridiculous as they sometimes seem..Gregorydavid 17:49, 24 August 2006 (UTC)

Yup. I'm sure clarity will come in the next few weeks/months. The decision just came out, not enough time for scholarly journals to hash over what the wording really means. --Bobblehead 17:51, 24 August 2006 (UTC)

Your hypothetical objects would not be planets under any reasonable definition of the word. Please see this paper. In short, the size of an object necessary to sweep an orbit gets larger the farther away the orbit is (because the circumference of the orbit is much larger). Looking at Mercury, it has a small orbit, so it doesn't need to be that big to sweep out its orbit (and it can't be that big because it only had a small orbit to accumulate material from in the first place). Now go out to the larger outer orbits ... the planets there are much bigger. But after Neptune there's no more planets. There's simply nothing out there that's large enough to have swept out its orbit, and if there was, we most definitely would have found it. --Cyde Weys 19:45, 24 August 2006 (UTC)

It's not really ambiguous at all, and has already had a good definition for awhile. Please see this paper. --Cyde Weys 18:29, 24 August 2006 (UTC)

We have a lot more work to do

Now that the designation "minor planet" has been abandoned, we have a lot of work to do to update all of the asteroid articles to change from "minor planet" to "small solar system body". One example of an article that needs to be updated is 991 McDonalda. I suppose the What links here on minor planet will be of good use. --Cyde Weys 19:08, 24 August 2006 (UTC)

This is hardly a job for humans: tell some robot to s/minor planet/small solar system body/ over all the articles. But before any of this is done, consider the plain fact that there are literally decades (and probably terabytes) of published research that use "asteroid", "minor planet" and so forth, but probably zero that use the new name. Would it not be better for Wikipedia to be conformant with extant literature and usage, particularly for those WP articles that quote from these sources? Furthermore, for all we know, astronomers will rapidly tire of a 23-character, 4 word name and just continue with 2-words, 11 characters (or 1 word, 8 letters)? It wouldn't be the first time the pronouncements of a standards body are simply ignored. mdf 19:25, 24 August 2006 (UTC)

Asteroid is still a perfectly good scientific word. The IAU even used it in their definition of small solar system body.Derek Balsam 19:27, 24 August 2006 (UTC)

Exactly, so why do some articles label things "minor planets" that are clearly asteroids? Asteroid is a subset of minor planet, so using the term asteroid should be more specific. --Cyde Weys 19:42, 24 August 2006 (UTC)

Because they are assigned names and numbers by an IAU sanctioned agency called the "Minor Planet Center"? That the vast, overwhelming majority (if not all) of the "minor planets" are asteroids -- ie, its effectively a synonym? And, somewhat irrelevantly, is Brian Marsden, right now, on a ladder ripping off the old neon sign and installing a more power efficient LED one that reads "Small Solar System Body Center"?  ;-) mdf 19:58, 24 August 2006 (UTC)

Building up the sssb page would seem the smart initial move, and figuring out exactly how the term is going to be used before mass-alteration of articles is probably advisable. We don't yet know how much currency the term is going to gain, and a note on minor planet etc is probably enough for now. Shimgray | talk | 20:08, 24 August 2006 (UTC)

Come to think of it, now might be a good time to sit down and figure out how best to handle all our solar-system-bodies articles... Shimgray | talk | 20:12, 24 August 2006 (UTC)

Charon and Pluto

Shouldn't Charon also be a dwarf planet now? Charon doesn't orbit around Pluto, they orbit each other... Does anyone have an explanation for why Pluto is a dwarf planet but Charon isn't? —Nightstallion (?) 19:17, 24 August 2006 (UTC)

• Does the IAU (now?) consider Charon to be a satellite rather than a dwarf planet...?  Regards, David Kernow 19:31, 24 August 2006 (UTC)

The IAU has publicly named only 3 bodies as dwarf planets. They have a dwarf planet watchlist which is not public, yet.Derek Balsam 19:39, 24 August 2006 (UTC)

Petition

Supposely there is petition for astronomers to overturn this redefinition of a planet. The reason is that only a small percentage of astronomers actually voted on the resolutions. See the "A farce" section of following news article. [7] --Daniel Schibuk 19:25, 24 August 2006 (UTC)

• Please forgive ignorance, but are the "424 astronomers ... out of about 10,000 professional astronomers around the globe" who were allowed to vote (a) the membership of the IAU; (b) some cabal within; and/or (c) those who were moved to vote...?  Thanks, David Kernow 19:36, 24 August 2006 (UTC)

This isn't likely to succeed ... the new definition actually makes a lot of sense. --Cyde Weys 19:40, 24 August 2006 (UTC)

Those were astronomers who were present at the time of the vote. If I understand the IAU voting system you must be present to vote so no absentee ballots. --Daniel Schibuk 20:05, 24 August 2006 (UTC)

The IAU's bylaws have, as I understand it, long accepted that a vote of the General Assembly is binding. "Overturning" this isn't going to happen, in the unlikely event that that many astronomers cared. Shimgray | talk | 20:15, 24 August 2006 (UTC)

LOL, someone gets unhappy with the result and think the whole thing needs to be reverted, simple as that. Don't waste time on this. -- G.S.K.Lee 20:22, 24 August 2006 (UTC)

I'd've hoped those of the "about 10,000 professional astronomers" who had an interest in the outcome of the vote (1) would've voted, arranged to vote or been represented; and (2) would accept the outcome. Then again, I guess they're human... allegedly... Chuckle, David Kernow 21:33, 24 August 2006 (UTC)

Actually, that's exactly what happened. The IAU executive committee proposed a definition that included lots of junk that nobody considered planets. About 2400 astronomers showed up to listen to what they had to say. Most of those thought it was ridiculous, so they re-wrote the definition. The new definition fits the way they've been using the term "planet" for decades. This definition will please most astronomers, and it will displease those who are unfamiliar with astronomy. So what. --Aelffin 16:16, 25 August 2006 (UTC)

Mike Brown's take on this whole thing is right here. (Remember, this is guy who started this whole thing with the discovery of "X"). A nice layman's explanation, if anyone's confused.--Planetary 00:58, 26 August 2006 (UTC)

effects on education

Should we allow a section on the effects on education, I mean learning about the planets is something we all learned in school haven't we?

You are fabricate something that even does not happen yet by doing this. Overreacting is not encouraged. -- G.S.K.Lee 20:23, 24 August 2006 (UTC)

Well, new textbooks will have to be purchased and/or many hours spent with the black marker removing references of pluto as a planet. Heh. Imagine the boon for the textbook and astronomical poster business! --Bobblehead 20:33, 24 August 2006 (UTC)

Bobblehead, that was an interesting thing to think about there, but you know I can imagine one kid out there who is researching about Pluto for his/her science class in Middle School, and tells her teacher "I don't have to do this report anymore, Pluto is not a planet no more!".

I think most teachers have said they'll adjust to the new IAU decision, I've heard they'll explain why Pluto is no longer a planet to students and such. Unlike most subjects in school Science is the most prone to change, and school districts usually keep tracks on that kinds of stuff so they can include them in their cirriculms. Falconleaf 01:32, 25 August 2006 (UTC)

Here's some news articles on the effects on education and other things, it also has some references to Disney's Pluto, and NASA's New Horizons which heading there. [8]

I am an editor of middle school and high school science textbooks. The new definition does impact our business and we'll be deciding soon what to do about it. From a publishing point of view, it's just a hassle--but the first draft would have been more of a hassle. From an educator's point of view, it's a great window on the concept of categorization--but the first draft proposal would have been better since it would have forced teachers to teach about a bunch of new objects. From an astronomer's point of view, the new definition is almost exactly what they've been saying all along--and the first draft proposal was a publicity stunt that would have confused things hopelessly. --Aelffin 16:24, 25 August 2006 (UTC)

To the guy who said I was overreacting, look at this [9], i think it's time we need to add a section regarding this, i mean it has impacted schools and other education-related stuff (inculding wikipedia) just as much as katrina effected new orleans.

Well, according to the first few articles that come up in that search, the decision to downgrade Pluto from planet to dwarf planet won't have an impact on schools as they are used to changes in science making their books obsolete, it's actually a good thing as it shows children that science is always changing, Pluto is a favorite among children (the whole cartoon dog thing) and some are sad that it isn't a planet anymore, and casinos are a better source of funding for schools than property taxes.--Bobblehead 20:53, 25 August 2006 (UTC)

As far as this impacting education like Katrina impacted New Orleans...No. Katrina destroyed New Orleans, this decision forces educators to bring things up to date, that's all. It's much better for science education since it teaches that accurate classification is important. Hopefully, this will mean that astronomy teachers will no longer ignore the Kuiper Belt, which is just as important a part of our solar system whether it contains Pluto or not. --Aelffin 17:42, 26 August 2006 (UTC)

Obsolete page needing merged

Someone might want to take a look at Candidate planets - it can probably be dropped into the original proposals section here quite easily, but it really doesn't seem to need to be a seperate page any more. Shimgray | talk | 20:45, 24 August 2006 (UTC)

Repressed Talk material could not have been more relevant

Now that the dust has settled at the IAU conference, I'd like to point out how completely in the wrong Cyde and others who lambasted speculations about the deficiencies of the original planetary redefinitions were. I'm not trying to say "na na nana na naa", I'm trying to get them to see the error of their ways in enforcing their overly narrow views on "relevance" in Talk pages. The people who were predicting an overturn of the original redefinition were portrayed by Cyde and others as distractions who were wasting space with their own predilections. Cyde even took a big chunk of these writings and threw then into a premature archive with the rude warning: "IMPORTANT NOTE: Wikipedia is not a discussion forum. These talk pages are for discussions on the article only, not the issue in general. Do not add to any of the archived comments below and do not post any new ones like them." Another in the Cyde camp insisted, "You are welcome to disagree, but that doesn't alter the fact that you are wrong. It is hardly "censorship" to request that people keep discussions on topic. You seem to be under the misapprehension that Wikipedia talk pages are chatrooms; they are not, they are places for discussing articles. Therefore it is utterly pointless for us to discuss matters like whether we think the IAU's definition of a planet is meaningful or not, because we cannot put our opinions of such matters into the article, per WP:NOR."

Well, as we all know now, those who were recording their dissatisfactions with the original IAU redefinition were spot on, and if their analyses had been paid more heed to, there would have been more investigation of the competing redefinition which eventually won over the committee, and therefore more 100% relevant material on those dissenters in the ARTICLE. Let this be a lesson to all would-be Talk Page Relevance Police. Stand down and let people simply Talk. This isn't article space, so just chill out. That has been the environment since the start of Wikipedia and a bunch of over-confident people who came to the project in `05 won't be changing it. JDG 20:57, 24 August 2006 (UTC)

I agree, as long as such speculation is kept in the talk pages. --Aelffin 16:10, 25 August 2006 (UTC)

Clear the neighbourhood

...has just been created, and was until a couple of minutes ago an explanation that it meant "clearing all other objects out of an orbit" and some weird theory about Neptune Isn't Really A Planet, See...

I've replaced it with something that's a little less wrong, but still crap (I'm terrible at explaining this) - could someone else have a go at it? Cyde? Shimgray | talk | 21:11, 24 August 2006 (UTC)

"Clearing the neighborhood" is such a pain in the neck cause rather than adding 3 planets, it downgraded my favorite planet, Pluto to nothing but a dwarf planet. Gosh, that dosen't have to do with anything about the term, planet. Alastor Moody _(talk) 02:25, 25 August 2006 (UTC)

Don't look upon it as losing a planet, but rather as gaining a Kuiper Belt. --Aelffin 16:02, 25 August 2006 (UTC)

If people cared about KBOs that'd be okay. Mostly it means Pluto will become a meaningless rock as obscure to most of the world as 1 Ceres. I think that's part of the explanation for the reaction. For some it's like taking away a part of people's childhood or making them feel like they've been lied to their whole life. Science might be ever changing and progressing, but humans are not like that. They like to be able to have things they can hold onto. For most people alive today the planets are apart of that. If you look at the history of 1 Ceres you'll see that asteroids of similar size were discovered within ten years of it. There was a gradual phasing out in many respects. This was sort of a "boom", for most folk, after 70 years. (Because in reality no KBO of similar size was found until 2002. The earlier ones were smaller and it was just a theory there'd be more as in many ways it still is)--T. Anthony 10:33, 26 August 2006 (UTC)

I admit, I was excited about the idea of getting dozens of new planets, so I supported the original IAU proposal at first. Then I learned that astronomers didn't like this proposal for a good reason: Pluto's orbit is controlled by resonance with Neptune. Furthermore, there's a whole family of KBOs that are also controlled by exactly the same orbital resonance; they're called plutinos. We can't call one plutino a planet and not call the others planets. That would be silly and confusing. --Aelffin 13:47, 26 August 2006 (UTC)

Need better image

The current image used to illustrate the 8 planets is not ideal, since it also shows Luna, a comet, asteroids, and the Sun. We should substitute another image, if one can be found, that only shows the 8 planets (and maybe the Sun as well). Kaldari 23:13, 24 August 2006 (UTC)

definitions

1. orbits a star, not something else or nothing (association)
2. big enough to be round, small enough to never fuse (middlingness)
3. clears a path for itself (domination)

• Anything that satisfies #2 is a planemo
• Anything that only satisfies #1 was a minor planet, now a sssb
• Anything that satisfies all three are the major planets (or just plain planet)
• Anything that satisfies #1 and #2 but not #3 is a dwarf planet

Does that seem right?

Perhaps they should have just called them major planets instead of classical planets.

Somehow this just seems to lead to the need to subclassify satellites into round and non-round...

- 132.205.93.19 02:32, 25 August 2006 (UTC)

Definition 1 is clearly problemattic. There's already some reason to think Interstellar planets might exist. In fact I read an astronomer objection to the first proposal because it would exclude such worlds. Definition two is acceptable in most cases. Definition three is very hard to justify considering the eccentricity we already find in other solar systems. I'm thinking in five-ten years we'll have to have another redefinition because this one is deeply flawed if not totally wrongheaded. (That said I'm skeptical a re-redefinition will put Pluto back as it has such a small mass)--T. Anthony 11:32, 25 August 2006 (UTC)

I believe the IAU stated somewhere or other in the debate that their current definition is only intended to apply to our solar system. Shimgray | talk | 14:27, 25 August 2006 (UTC)

I believe they specifically voted against calling them "classical planets" and the term "major planets" came up in discussion but was never committed to paper AFAIK. They're just "planets" plain and simple. Other than that, I think you've covered the terms pretty well. --Aelffin 04:06, 25 August 2006 (UTC)

This is all very interesting, but is there any scientific or conceptual benefit to defining planets or is this just a PR move? Gnosticdogma 14:24, 25 August 2006 (UTC)

There is no scientific benifit to this one way or the other. Whatever astronomers call an object, be it "planet", "KBO" or "Dorothy," does not in any way change what it is or alter its scientific value. That this definition was set to end public confusion is correct, but it's hardly a "PR move." If it was, it was a pretty lousy one. The general public are not going to like this definition. Not one bit. Serendipodous 14:27, 25 August 2006 (UTC)

Well, nature may not care what we call things, but good nomenclature is very useful in the process of science and poor nomenclature can be very problematic. If the terms we use don't match up with natural categories, then plenty of unnecessary confusion can be introduced into the discourse...and if we keep changing the terms we use, then we lose understanding of things written in the past. The first draft proposal was, in the view of many astronomers, a PR move on the part of the IAU executive committee. The fact that hundreds of astronomers opposed the committee is a testament to the importance scientists place upon nomenclature. In the end, the majority of astronomers (rightly) got their way: the final definition of the word planet represents both the working definition that astronomers have been using for decades, and the categories that nature presents us with. --Aelffin 16:01, 25 August 2006 (UTC)

NO. 500 out of 10,000 astronomers voted on this. Indeed many are calling shinanigans on the whole process and lack of electronic voting options. Regardless, I suspect there are more people out there opposed to this definition than in favour: http://news.bbc.co.uk/1/hi/sci/tech/5283956.stm <- Pluto Vote Hijacked Revolt. --Walshicus

Anybody who cared enough to join the IAU could have been there. It's expensive, but not too expensive for a professional astronomer to easily have underwritten. 2400+ astronomers showed up in Prague. About 500 cared enough to vote. More than 2/3 of those voted for the current definition. All astronomers recognize the IAU as their governing body. Most astronomers don't give a damn because most astronomers don't deal with planetary dynamics. The decision reflects the definition that the professional planetary scientists have accepted for a long time. --Aelffin 18:49, 25 August 2006 (UTC)

If it has been the definition for "a very long time" than they should have changed it long ago. Allowing it to be considered a planet this long, in this media aware age, seems unusually foolish. Also I'm curious what your evidence is that it's been seen this way "for decades." Kuiper objects of Pluto's size were only theoretical until the early 1990s. Added to that there's a great deal we still do not know of Pluto as we've had no mission to it. You may disagree, but there's a great deal we actually learn by observing a planet or moon more closely. If this was something understood decades ago it should've been changed decades ago. Or alternatively if the probe in 2012 had definitively proved it is identical to a KBO they could've had new evidence to make the decision then. Possibly they could've just made it clear that for the purpose of astronomy Pluto is no longer a planet, but that they have no say on culture so we can call it one if we wish. That's essentially been the status quo since 1992. They might be wise to add such a proviso if it's still an option.--T. Anthony 05:59, 26 August 2006 (UTC)

I agree, they should have ruled on this a long time ago. However, astronomers have the right to define an astronomy term for astronomical purposes. You can call it whatever you want. But, then again you can call a whale a fish if you want. I'll let you decide which makes more sense. I'll tell you why it makes more sense to call Pluto a KBO: because it is part of the Kuiper Belt. That is defined by its orbit, and we don't have to send a probe there to determine its orbit. Can a KBO be a planet too? Perhaps, but it would get really confusing if we start calling some KBOs planets and others planetoids, etc. The smartest thing to do is to group objects based similarity in features we can currently observe. --Aelffin 4:27 EST

What I mean to say is, is this nomenclature useful? Is it conceptualizing important information; is there a meaningful difference between a 'planet' and a 'dwarf planet' and (if one should ever be found) a 'rogue planet'? Is there a reason, in other words, that scientists should care if an object orbits the sun, is in hydrostatic equilibrium, and has cleared its neighborhood? Does meeting those criteria suggest that an object will be similar in any other way to other objects in the same class (such as in stellar classification)? Or is this an arbitrary distinction? Gnosticdogma 17:40, 25 August 2006 (UTC)

The nomenclature is incomplete to be sure, but it is useful. The sructure of the solar system if you just look at it without naming anything is this:

SPHERE SPHERE SPHERE SPHERE / RUBBLE / SPHERE SPHERE SPHERE SPHERE / RUBBLE.

This naturally suggests a category for the big spheres, and a category for the rubble. I think the whole "dwarf planet" thing is unnecessary, but it does make a distinction between round rubble and irregular rubble--is that useful? Not really, it's just kinda cute. As far as Pluto's place...it belongs with the rubble. Nature decided that, not the IAU. The IAU is just finally accepting Pluto as an official part of its true family, the Kuiper Belt. --Aelffin 18:38, 25 August 2006 (UTC)

Honestly, I don't think it suggests anything of the kind. The sample size is way too small to suggest that whatever "pattern" may exist in the objects orbiting the sun is anything but random. There also happens to be quite a lot of rubble within the orbits of the traditional planets; see trojan asteroid. Also, you are implicitly suggesting that being a planet (and not rubble) is somehow important. Why is it important? Gnosticdogma 18:57, 25 August 2006 (UTC)

Well, there certainly is plenty besides the two major rubble belts. But they're anything but random. The Trojans are accessory objects to Jupiter. The plutinos are accessory objects to Neptune. The NEOs are accessory objects to Earth. Essentially, if it's not a major planet, it is either governed by a major planet or it is confined to a certain zone. The solar system is very highly structured, and the best approach is to adopt a nomenclature suited to clarifying what part of that structure a body belongs to. As far as importance goes...I'm suggesting that we treat the rubble systematically, like we treat the planets systematically, it's not the objects that are important, but the overal structure that's important. Anyway, we're talking about a sample size of thousands of objects, most of which fall into clearly defined families as defined by key paramaters of their orbital mechanics. We know that Pluto is a type of plutino, and that makes it part of the Kuiper Belt. It's our choice whether to call some Kuiper Belt objects planets or not, but I think if you do, you blur the line between a very real structure within the solar system and other very real structures within the solar system. --Aelffin 19:01, 25 August 2006 (UTC)

You misunderstand me. I do not mean to imply that the solar system is not ordered or that orbital mechanics does not create its structure. I mean to say, that the pattern of the objects in the solar system is probably arbitrary insofar as it didn't necessarily have to turn out the way it did. "Planet planet planet planet rubble" may be nothing more than random chance. The sample size I was refering to was the solar system itself, not the objects within it. If this definition of planet is useful for the purposes of orbital mechanics, then it makes sense to have the definition. I'll take your word for it. Gnosticdogma 19:23, 25 August 2006 (UTC)

Oh, I see. I didn't mean to imply that the particular order of the planets and the rubble was somehow intrisnic or necessary. I just meant to say that the position and structure of the rubble belts are governed by the positions and gravity that the planets happen to be in. In other solar systems (and we know of more than a hundred now), it's almost certain that the rubble will be in different positions than they are in our solar system, but it's also certain that those positions will also be governed by the gravity of the planets within those systems. I do think the definition is useful for understanding the orbital mechanics of our solar system and others, but you don't have to take my word for it. Somebody else (Cyde, I believe) posted a link above to a very good paper called "What is a Planet?" that explains the relationsips quite well. --Aelffin 19:55, 25 August 2006 (UTC)

Hydrostatic equilibrium

"Other planetary satellites (for example, in the Earth and Moon system) might be in hydrostatic equilibrium,"

Is this what we mean here?

Hydrostatic equilibrium refers to the planet itself not its relationship eith other celestial objects. Dr. Guillermo A. Sanz-Berney 03:52, 25 August 2006 (UTC)

from the final defn

"(3) All other objects [3] except satellites orbiting the Sun shall be referred to collectively as "Small Solar System Bodies"."

What satellites orbiting the sun does that mean? artificial satellites? moons of the planets? there's no 4th category for any other objects. SpookyMulder 11:00, 25 August 2006 (UTC)

We already have an article on that: Small solar system body. --Cpt. Morgan (Reinoutr) 12:22, 25 August 2006 (UTC)

That "except satellites" keeps creeping in; is it in the actual definition? Shimgray | talk | 13:42, 25 August 2006 (UTC)

I've sourced the exact text as voted on and removed "except satellites". Someone keeps trying to add it in, presumably in an attempt to simplify... Shimgray | talk | 13:56, 25 August 2006 (UTC)

No, 'someone' is not; I have put it there because it is in the final definition but not in the version which was published when the Assembly session began. It was inserted during the debate so as to prevent satellites (including large bodies such as Ganymede and Callisto) from being classified as SSSBs, which they ought not to be. --Ross UK 21:52, 25 August 2006 (UTC)

The continents?

By a similar logic should the Indian subcontinent now be just be called a continent in schools? It seems like maybe it would make even more sense to do so. India has its own plate and was separate from Asia for millions of years. Is there a geological teaching body to deal with this?--T. Anthony 12:52, 25 August 2006 (UTC)

You should bring it up at the IGU (International Geological Union) Assembly...DrCito 15:43, 25 August 2006 (UTC)

You mean the IUGS, which I believe (wisely) leaves such matters as the definition of continents alone. --Aelffin 16:06, 25 August 2006 (UTC)

The IUGS has the advantage that they can just ignore it - after all, no-one's going to discover a new continent tomorrow. Astronomers need to look towards the future a little more... Shimgray | talk | 16:10, 25 August 2006 (UTC)

Not tomorrow, but eventually, we will discover new continents, most probably on other planets (whatever that word means). I guess the IUGS are smart to avoid this discussion because a clear definition would not really help anybody just like the so called new "clear" definition of a planet didn't help anybody either. 206.47.141.21 16:25, 25 August 2006 (UTC)

True, this could concievably become an issue once we start looking more closely at the crustal dynamics of Venus and Mars, as well as the icy satellites of the outer solar system. Sure, we don't use the unqualified term "continent" much, but we do talk about tectonic plates, etc. These may have to be reconceptualized in terms of the planets in the not-too-distant future. I once read a paper that described the Venusian crust in terms of "ice pack tectonics" as opposed to the conveyor belt analogy we use on Earth. So, does Venus have tectonic plates or not? That may eventually come down to a vote. But clarifying the definition could be extremely valuable. I think the "new" definition of planet (which is actually the same as astronomers have been saying all along) has in fact clarified the public's understanding of what scientist meant when they said "planet" in the past. --Aelffin 16:31, 25 August 2006 (UTC)

Actually I was trying to be a smart ass... and I came out with a similar acronym for a geological agency, go figure. lol.DrCito 17:23, 25 August 2006 (UTC)

Earth article

Can someone who understands what the changes are please make edits to the Earth article to bring it upto date --Gnangarra 01:31, 25 August 2006 (UTC)

I tell you what "clear the neighbourhood" means. A big tornado runs through the town and leaves almost nothing but a handful of toilets and basements behind, that's "clear the neighbourhood", even if not all of your neighbours were sucked away. Put Earth or Neptune into the place of tornado and you get it. And as I understand, the orbit of Pluto is in resonance with Neptune's, which means Neptune has effectively "cleared its neighbourhood", and Pluto is the lucky toilet which managed to move into a resonance orbit and avoided being eaten by Neptune. -- G.S.K.Lee 13:13, 25 August 2006 (UTC)

Pluto is not in Neptune's orbit as it orbits at an angle so there is no way for it to be gobbled up by it. Still I'll withdrawal my insulting post and I hope you withdrawal any insult on me.--T. Anthony 13:22, 25 August 2006 (UTC)

Well, here is an article that contains more details which you need to read and eliminate the misconception. -- G.S.K.Lee 16:23, 25 August 2006 (UTC)

I take it then you don't withdrawal being personally insulting to me even though I withdrew a post which was simply sarcastic and not aimed at you. Citing a Wikipedia article says almost nothing to me. In many respects I know and understand why it was demoted. However people are treating this like it can't be discussed, as if 300 astronomers can undo 76 years of history without any argument. Even the Big Bang theory didn't go down like that and it's based on solid observational standing. Pluto being or not being a planet is being treated, by some, like an immutable reality when it's only a matter of classification. Classifications change. The example of continents is relevant there and has been mentioned by geologists. At the very least it seems fair to give people time to complain and adjust to this.--T. Anthony 00:21, 26 August 2006 (UTC)

I have no idea what you are talking about. Insults? This is the first and only thread of discussions I am directing towards you directly. Apparently you messed me up with someone else. Either you calm yourself down or I am not going to waste anymore time on one that cannot recognize the names properly. -- G.S.K.Lee 08:01, 26 August 2006 (UTC)

Pluto does not have to pass "through" Neptune's orbit to be influenced by it.DrCito 15:46, 25 August 2006 (UTC)

Better point, let me think on that.--T. Anthony 00:21, 26 August 2006 (UTC)

Some slight humour on the subject

http://img.photobucket.com/albums/v131/selfbiased/pluto.jpg

doktorb _words^deeds 14:19, 25 August 2006 (UTC)

I was looking forward to seing what this was, but it appears the URL is bad. If it's not just me being a moron, can you repost? Stoneice02 07:25, 26 August 2006 (UTC)

You needed to remove the spaces in the URL. Done. kwami 14:14, 26 August 2006 (UTC)

New Information

I just read on an astronomy news forum that they might be changing Pluto's designation back. [removed link to nonrelated page] This could be important. Triumph's Hour 00:46, 26 August 2006 (UTC)

Hahaha, very funny. If you do this again I will block you for disruption of Wikipedia.

For other readers: please do not click on the above link if you are not above the age of 18 or are barred from viewing pornographic material by laws applicable in your community. -- ran (talk) 02:16, 26 August 2006 (UTC)

Sounds like I got you good ran. Just injecting a little humor into a dry subject.

P.S. How many "spins" did you watch? Triumph's Hour 02:22, 26 August 2006 (UTC)

Ongoing Controversy

The controversy of the final vote needs to be expanded on, especially the whole feud between the dynamicists and the geologists and the questionable legitimacy of the final vote agreed on (i.e. holding a vote after almost everybody left).

Some information can be found here. http://news.bbc.co.uk/2/hi/science/nature/5283956.stm --Thirdmoon 00:53, 26 August 2006 (UTC)

Only 400 out of 10000 voted for this stupid notion to demote Pluto eh? Well I just lost all respect for the IAU. user:MagnumSerpentine 8-26-06

Unnecessary Sentence?

Seems like the sentence Of course, the IAU decision does not change Pluto's physical characteristics; Pluto has been small, distant, eccentric in orbit, and in close quarters with other spatial bodies throughout human history. is unnecessary for two reasons. One, do we really expect anyone to read the article and think to themselves, "Hmmm... so Pluto is no longer a -insert Pluto's physical attributes-"? IMHO, it would be like adding a statement in a country's entry that the birth of the country did not result in actual lines being drawn on the ground to signify the border. Second, this article is about the redefinition (although I agree it should be the definition since no original definition was ever formalized) of a planet... not so much about Pluto itself. Information on Pluto's history and physical characteristics, except to point out how they differ from the definition of a planet, should be left to Pluto's article. Hope that all made sense. Stoneice02 07:17, 26 August 2006 (UTC)

I removed the first sentence. Twas unnecessary indeed. Marskell 09:15, 26 August 2006 (UTC)

---

I wrote that sentence, to replace:

"Of course, the IAU decision does not actually change anything; Pluto was never a planet."

Which not only played on the inherent paradox of definition/redefinition that is central to this article; it was downright smart ass. But considering the number of people I am encountering in day to day life who seem to think that the aforementioned celestial body will shortly cease to exist as a result of the IAU's decision, (a travesty, they feel) I felt that something to the effect of "Pluto is not changing; We are." was indeed useful somewhere in the article, in order to help laymen understand what's going on. This is the same sort of problem that average people have with the concept of scientific 'Theories'. The ideas that explain the reality change, but the reality they are drawn from is constant. Understanding this is central to the public reaction to the 'redefinition'.

I admit the placing of the sentence was far from optimal. If someone could suggest a place in the article where comments to that effect could be inserted, I would be most obliged. Robin Moshe 17:48, 26 August 2006 (UTC)

Phrasing of final definition

Someone keeps changing sentence 3 from

All other objects [3] orbiting the Sun shall be referred to collectively as Small Solar System Bodies

to

All other objects [3] except satellites orbiting the Sun shall be referred to collectively as Small Solar System Bodies

I've had to fix this a few times now, on various pages. Whoever it is, could they please not do this? "Except satellites" may make it appear to be more clear, but it's just confusing in the long run, not to mention the fact it's misrepresenting what the final definition was (see fn.31) Shimgray | talk | 08:41, 26 August 2006 (UTC)

The definition as accepted by the GA does include the words "except satellites" [10] (Your link refers to the draft put to vote). The words were added as a clarification after a comment from the plenary during the voting session. --Scan 12:09, 26 August 2006 (UTC)

Oh, god, of course! I feel a right idiot now, I'd forgotten that drafting amendment and I was watching the damn thing... Shimgray | talk | 12:13, 26 August 2006 (UTC)

This is indeed true, as I said above. No bother though. --Ross UK 20:02, 26 August 2006 (UTC)

Images

I'm really bad at this stuff, but is there any way the font on the images could be made a bit bigger? I find it really hard to make out a lot of the writing on the diagrams illustrating the different definitions. They're a great idea, but I can't read them. Nice work here otherwise. Skittle 09:39, 26 August 2006 (UTC)

Uruguayans take credit for demoding Pluto

I found this in the Newspaper today, it's credited to AFP and EFE. However, I'm having a hard time putting it into the article, if you check the history it's turning into a revert war. Where do I put it? and, can one of you put it since I will no longer have this IP tomorrow?

The newspaper is El Nacional of venezuela, page B-13 The full text says (translated from Spanish to English by me, of course)

Uruguay celebrates Pluto's exit
Montevideo-Brazil/AFP-EFE
The uruguayan astronomers Julo Fernández and Gonzalo Tancredi were who rebelled at the gerenal assembly of the International Astronómical Union that took place in Prague and managed take Pluto out of the Solar System.
Asked if Uruguay kicked Pluto out of the Solar System, Tancredi answered on the phone from the Prague airport: "Yes, when you put it that way, it could be".
"I feel it as a misunderstanding having considered Pluto as a planet for 75 years", said Tancredi. He considered its demotion to dwarf planet demonstrates that science is dynamic and that it recognizes its mistakes.
The executive proposed an ammendment to the assembly to establish two categories of planets, the classical, that is to say, eight, and the dwarves. Met with the uruguayan counterproposal, the assembly ended up adopting the idea that the dwarf planets were just too small to be considered planets.

There's an inset (you know, a tillte box with a subtitle) where it goes on to say Pluto is still considered important both for astrology and astronomy, but I don't think that part is important to this discussion.
200.44.6.22 16:40, 26 August 2006 (UTC)

The South American view seems to be a pretty biased one: as you can read in [11] (fourth point) the Tancredi et al proposal is about as far as the original committee one from the final version, if not more so. They may take credit for being the loudest voice against, but the final prop was agreed on in a dedicated session on Teusday evening. --Scan

That may very well be, but after adding it, I read the whole article slowly (I had skimmed it at first searching for their names, but didn't see them) and found that Fernández (or was it Tancredi?) were already added in by someone else using a non- South American source.
And actually, to tell you the truth, I'm not saying they should really take the credit, as much as the blame. From this last sentence, you can obviously tell I'm not that happy Pluto was demoded, but am, after all, trying to keep NPOV.
200.44.6.22 21:56, 26 August 2006 (UTC)

The initial counterdraft was first-authored by Tancredi, later Fernández took the lead on this draft. However, I know many Astronomers from all continents opposing the initial committees suggestion. I actually think it's not doing any good to the issue approaching it in a we-xxxians-did-it or equally we-xxxians-succeeded-to-keep-Pluto. Such a business should be and, as I can judge from the way the general assembly went, also was run on a purely inter- or non-national basis. --Scan 23:04, 26 August 2006 (UTC)

Timeline

"According to point (1) the eight classical planets discovered before 1900"

Good point. Can we get a visual timeline of when each planet was discovered? Was Pluto much later than the rest? — Omegatron 00:20, 27 August 2006 (UTC)

Off the top of my head, five antiquity, Uranus 1780, minor planets 1800-1850 before downclassed, Neptune 1840, Pluto 1930. So, yes, Pluto was the only "modern" planet, where I'm making the sweeping definition of "modern astronomy started with photographs"... Shimgray | talk | 10:03, 27 August 2006 (UTC)

That's what I suspected. — Omegatron 13:41, 27 August 2006 (UTC)

Really weak intro

As of this writing the intro is incredibly weak. Why is one of the planetary criteria given as if it's the only one, or the ascendant one? Why go on about difficulties with the vote and such? If this stuff merits being in the article at all, it should be in its own section near the end. Where is the summary of the original redefinition (the one that was eventually defeated) and the summary of the finally adopted one? Those, stated as briefly as possible, should be in the intro w/o doubt. JDG 06:34, 27 August 2006 (UTC)

I've modified the intro to add all the concpets of the new definition not just the clearing the neighborhood part. I also agree the voting issue is not essentail for the intro, if at all. DrCito 07:39, 27 August 2006 (UTC)

Agreed, it needs more work. --Ross UK 18:32, 27 August 2006 (UTC)

Criticism of Final Draft

We need to watch developments here closely. Dr. Alan Stern doesn't seem to be fully versed in the new definition, and Earth clearly qualifies as a planet. His count of the number of near-Earth asteroids is already covered by the new definition. I'm not sure if this paragraph even belongs in the article. I'm also not sure how to say this in the article without it looking like it's taking sides. -- MiguelMunoz 07:16, 27 August 2006 (UTC)

The last paragraph of criticism now states that about 1,000 people were in attendance. This needs to be referenced as it is different than 400 (4% of 10,000) according to Alan Stern who is referenced. In addition, the reuse of the reference "BBC:Pluto vote 'hijacked' in revolt" seems misapplied in the last sentence as it does not support it. Is there another reference? Ekem 21:13, 27 August 2006 (UTC)

Actually, Stern was not there, he just sums up the votes cast wrt. resolution 6A (see in [12]) and assumes this is the number of people present who had the right to vote also earlier in the session. This is a pretty fishy interpretation anyway. The Austrian astronomer Guenther Wuchterl, who was present during the GA, for instance reports about only 30 votes cast in favour of 5B vs. 800 voting people in total [13]. NASA, btw, has already declared to respect the decision [14], and ESO will for sure do the same (remember the incoming IAU president is the DG of ESO) --Scan 02:35, 28 August 2006 (UTC)

Vote 'controversy'

Stuff about the supposed voting controversy should really be taken out of the introduction. By the way, I don't see what the controversy is; if people don't attend the GA it is their own affair, but they should not whinge afterwards. Likewise, if people who do attend the conference cannot be bothered to wait until it ends before leaving they can have no complaint. As to the timing of the vote, this is how things always seem to be done: resolutions are determined upon on the final day, shortly before the closing ceremony. So what is the problem? Incidentally, I speak as someone who was disappointed by the result reached. --Ross UK 23:56, 27 August 2006 (UTC)

• I agree that it does not belong in the introduction and placed it into the criticism section. This avoids duplication.Ekem 00:54, 28 August 2006 (UTC)

For what it's worth, this is a large enough change that we were guaranteed to get whingers no matter what, no matter how invalid their complaints are. Look at the head of the New Horizons mission who is embarrassing himself by not even understanding what "clearing its neighborhood" means. Now obviously he has a hat in the ring, because his mission probably wouldn't even have been approved if it wasn't for the fact that they were "exploring the last unexplored planet". --Cyde Weys 01:55, 28 August 2006 (UTC)

Oh, Stern knows precisely what it means, he was even the one defining the Λ-Paramater used by Soter to quantify the concept. Soter actually shows that, invoking this parameter the "planet" regime differs from the "dwarf planet" regime by about five orders of magnitude. Stern just chooses to ignore what he knows to be able to throw more PR-mud. --Scan 02:52, 28 August 2006 (UTC)

Wow, I didn't realize Stern was being so scumbaggish. I expect this kind of behavior in politics, not in science. Would there be a way to include this in the article as a refutation under the criticism section? It surely is relevant that Stern is accusing planets of not "clearing their zones" when he knows exactly what that actually means, and that they have actually cleared their zones. --Cyde Weys 05:05, 28 August 2006 (UTC)

Edit to Planet definition

Re-inserted text about a planets mass that was removed. I think this is an important point as object may be round for other reasons. Also changed the link to point at the IAU web page with the definition to act as verification of the definition. myork 12:51, 28 August 2006 (UTC)