Pluto is out---only 8 planets now---it's official :(

[Martin]

http://www.guardian.co.uk/uklatest/story/0,,-6035526,00.html

 

I think they made a mistake but I am glad they finally decided.

 

The Prague conference of astronomers demoted Pluto

[J.C.MacSwell]

http://www.guardian.co.uk/uklatest/story/0' date=',-6035526,00.html

 

I think they made a mistake but I am glad they finally decided.

 

The Prague conference of astronomers demoted Pluto[/quote']

 

Anyone else feel like our Solar System"seems" different today?

 

My $.02:

 

I agree with the decision, not necessarily the criterion they used to toss it, but it may work for our particular System. Hopefully Pluto will stick around and not feel shunned.

[Royston]

The Prague conference of astronomers demoted Pluto

 

Bah ! I was getting quite used to the idea of Pluto being one of the family...it deserves planet status just for the tenure of the debate. What's with the 'dwarf' planets, is this similar to the (now rejected) plutons category ?

[Martin]

Mike Brown (Caltech, co-discov. Sedna, Xena? etc) was against changing the list of planets. Heard him talking to Ira Flatow on NPR Talk of the Nation: Science Friday.

 

He made a good point. He said look at what qualifies as a CONTINENT. It is really a cultural, not a geological definition.

 

why should Europe be a continent.

if Australia is a continent, instead of an island, then why not Greenland too?

 

if Europe is a continent then why not India?

 

So he concluded once you have some set of things (continents, planets) embedded in the culture and language, then it is no longer a scientific definition and there is no need to mess with it.

[J'Dona]

It's about time, I think. I know that the word "planet" has no significant bearing in science itself, but culturally Pluto really always has been different, or treated differently, from the rest of what were the nine planets. But forget about it feeling left out: it's now the chief prototype for an entirely new classification of stellar bodies.

 

My only question is, if one of the criteria now for a planet is that the object must have "cleared the neighbourhood around its orbit," then does this mean that Neptune technically isn't a planet because it hasn't cleared Pluto, which crosses its orbit?

[YT2095]

OMGZ !!!!!111ONE ONE11!!11!!!ONE

 

Science Sued by Astrologers/Horoscope readers Planet wide!

 

the irony is, that IIRC, it`s already been attempted once

 

I wonder if Mickey, Goofy and Donald are likely to Protest?

[gcol]

A big "hear hear" to Martin. The whole storm in a teacup is a semantic nonsense. More than one discussion in these fora has become heated by accusations of semantics. For such a supposedly august body to waste time over it is laughable. And did you see the televised voting procedure? That was a real disorganised circus, hilarious, even the commentators were snorting with derision.

 

(India is a sub-continent, I believe, so I can meet the astronomers halfway and possibly agree that Pluto is a "sub-planet")

[J.C.MacSwell]

OMGZ !!!!!111ONE ONE11!!11!!!ONE

 

Science Sued by Astrologers/Horoscope readers Planet wide!

 

the irony is' date=' that IIRC, it`s already been attempted once [/quote']

 

Fortunately we made the cut and that expression is still good!

[Steph]

 

My only question is' date=' if one of the criteria now for a planet is that the object must have "cleared the neighbourhood around its orbit," then does this mean that Neptune technically isn't a planet because it hasn't cleared Pluto, which crosses its orbit? [/quote']

 

I have the same question... but maybe its if there are two objects, you take the larger one?

 

also... is the moon considered a dwarf planet? if Ceres is...

[J.C.MacSwell]

It's about time' date=' I think. I know that the word "planet" has no significant bearing in science itself, but culturally Pluto really always has been different, or treated differently, from the rest of what were the nine planets. But forget about it feeling left out: it's now the chief prototype for an entirely new classification of stellar bodies.

 

My only question is, if one of the criteria now for a planet is that the object must have "[b']cleared the neighbourhood around its orbit,[/b]" then does this mean that Neptune technically isn't a planet because it hasn't cleared Pluto, which crosses its orbit?

 

I have read this in some reports and "dominant in it's area" in others.

[Sisyphus]

 

also... is the moon considered a dwarf planet? if Ceres is...

 

But the Moon orbits around the Earth, and Ceres orbits around the Sun.

[YT2095]

can`t you have a Binary system of planets?

they orbit each other, but Both orbit a Star.

[Martin]

According to BBC

 

 

http://news.bbc.co.uk/1/hi/world/5282440.stm

 

the official terminology for things like Pluto is now "DWARF PLANET".

 

 

But that is poor.

 

Ceres is a "minor planet" and has often been called that, any large round asteroid can be a "minor planet"

 

what we are talking about is TRANSNEPTUNE stuff like Sedna and Xena and Pluto

=====================

 

so let's come up with a good name for round transneptune bodies like pluto

Any suggestions?

 

I think they should be called DOLPHINS

 

So Pluto was the first Dolphin to be discovered. And one or more of the other Dolphins (like Sedna, Xena, ...) may actually turn out to be larger than Pluto. And Mike Brown of Caltech has discovered more Dolphins than anybody else. And so on.

 

Any other suggestions? Nominate some other terms and we can have a poll.

[J.C.MacSwell]

can`t you have a Binary system of planets?

they orbit each other' date=' but Both orbit a Star.[/quote']

 

That's why I think it might work for our system but be more ambiguous for other stars. Pluto and Charon can both be dwarf or minor planets since they don't orbit a major planet, and we are unlikely (I think?) to find any more major ones.

[J.C.MacSwell]

 

I think they should be called DOLPHINS

 

.

 

For what porpoise?

 

(I would hate to see the suggestions if they were transuranus )

[YT2095]

actualy aren`t some of Jupiters Moons (or at least one of them) large enough to qualify as a planet(oid).

don`t ask me which one(s) I forgot.

 

I could also be wrong.

[Sisyphus]

can`t you have a Binary system of planets?

they orbit each other' date=' but Both orbit a Star.[/quote']

 

Yes, but I think the terminology is defined such that if the center of gravity of the two bodies is within one of them, the one it's within is the planet and the other is a moon. Pluto/Charon can be a binary system of planets (or whatever they're called now) because the center of gravity is between them. Our moon is definitely big enough to be a planet, but the center of gravity of Earth/Moon is inside the Earth. Same for Jupiter's moons, etc.

[YT2095]

well yeah, you can`t lose with Jupiter can you on a Gravity match

Earth would be a "Moon" (and probably capable of orbiting it happily too) by comparison.

 

 

ignoring the radiation and stuff that is

[J.C.MacSwell]

Pluto should have been given a grace period lasting til the end of '06.

 

This would have allowed for "farewell to Pluto" parties to bring in the New Year.

[J.C.MacSwell]

well yeah' date=' you can`t lose with Jupiter can you on a Gravity match

Earth would be a "Moon" ([b']and probably capable of orbiting it happily too[/b]) by comparison.

 

 

ignoring the radiation and stuff that is

 

As long as we weren't in geosync with the "Eye".

 

Can you imagine that thing staring at you full time?

[swansont]

It was insinuated at work today that there was some anti-American sentiment at play in the whole process, as the outcome was to strip several American discoveries of (potential) planethood.

 

I am not advocating any of that as true. Just passing along some astronomer scuttlebut. Palace intrigue, conspiracy theory, and all that.

[Martin]

It was insinuated at work today that there was some anti-American sentiment at play in the whole process' date=' as the outcome was to strip several American discoveries of (potential) planethood.

 

I am not advocating any of that as true. Just passing along some astronomer scuttlebut. Palace intrigue, conspiracy theory, and all that.[/quote']

 

Interesting idea, maybe it weighed in the balance with other stuff.

IIRC the recent American discoveries have been largely discoveries of

Mike Brown.

 

Here is something of his called What is a Planet?

http://arxiv.org/abs/astro-ph/0608417

published in Annual Reviews of Earth and Planetary Science 2006 v. 34

 

He would have had the honor of having discovered and named several recent "planets".

 

But I heard him say he didn't WANT that. He said broadening the definiton of planet to include Pluto and his finds like Sedna and Xena etc would be a mess----he warned that it would eventually get you 50-200 new "planets"

 

(it would be open-ended, not stop at just the 12 that you would have right away)

 

so regardless of whether there was Anti sentiments floating around, or various kinds of jealousy, probably it doesnt matter----in the end they were RIGHT not to expand the definition---and in the end they did more or less what Mike Brown happened to be recommending

 

(he said he would actually prefer just leaving it with an unscientific "cultural" definition---the 9 we are used to, but if that want acceptable then make it 8 planets, like they did)

 

Germans ought to be disgusted by the change because they have this

mnemonic

 

Mein Vater Erklärt Mir Jeden Sonntag Unsere Neun Planeten.

 

now their mnemonic is spoiled.

 

http://de.wikipedia.org/wiki/Mnemotechnik

 

(my father explains to me every Sunday our nine planets)

[Deified]

That's very interesting about the anti-american stuff.

 

Any word on Charon? The press release said that there would be (initially) only three dwarf planets (Pluto, Ceres, Xena), but as far as I can tell, Charon fits the criteria. Is it one of the twelve candidates? Or is there something I'm missing?

 

Also, Is anyone gonna care? Do you think that this scientific redefinition might have very little effect on public perception. (If we taught kids that there was a lot more out there than just nine planets we might not be having this problem.)

[swansont]

Interesting idea' date=' maybe it weighed in the balance with other stuff.

IIRC the recent American discoveries have been largely discoveries of

Mike Brown.

 

Here is something of his called [b']What is a Planet?[/b]

http://arxiv.org/abs/astro-ph/0608417

published in Annual Reviews of Earth and Planetary Science 2006 v. 34

 

He would have had the honor of having discovered and named several recent "planets".

 

But I heard him say he didn't WANT that. He said broadening the definiton of planet to include Pluto and his finds like Sedna and Xena etc would be a mess----he warned that it would eventually get you 50-200 new "planets"

 

(it would be open-ended, not stop at just the 12 that you would have right away)

 

so regardless of whether there was Anti sentiments floating around, or various kinds of jealousy, probably it doesnt matter----in the end they were RIGHT not to expand the definition---and in the end they did more or less what Mike Brown happened to be recommending

 

(he said he would actually prefer just leaving it with an unscientific "cultural" definition---the 9 we are used to, but if that want acceptable then make it 8 planets, like they did)

 

I think he's got a point about the cultural definition (watch out now, not to be outdone, maybe the geologists will redefine "continent.")

 

The conspiracy grumbling includes the fact that the IAU had, in recent years, disenfranchised its members (though their vote was reinstated by the time of the Prague meeting for this issue) and that what proposals were to be voted on were controlled by a relatively small number of astronomers on some committee. So it's possible, maybe, to have come up with a definition that would have included Pluto, Charon and Xena, but without opening the door for the dozens of others, but it never got to a vote.

 

But it's all gossip, not science.

[CPL.Luke]

I think we really should just go with it and say their could be a few dozen planets in our solar system, we could just call the 8 "inner" planets the core planets. and omit the rest from general knowledge requirements

 

the current definition just seems too skeevy in the scientific sense.