8 planets it is then

[mojo]

"Astronomers meeting in the Czech capital have voted to strip Pluto of its status as a planet.... Astronomers rejected a proposal that would have retained Pluto as a planet and brought three other objects into the cosmic club."
http://news.bbc.co.uk/2/hi/science/nature/5282440.stm

Which will need a rider added to the phrase I learnt in primary school... My Very Energetic Mother Jumped Somewhere Up Near except Pluto.

[ballaratdragons]

Thanks Terry,

Not good news mate!

Just in case some say "that's only what the BBC News says" here is the link to the actual Resolution results on the actual IAU site (International Astronomical Union). Scroll to the bottom for resolution 5a & 6a.

http://www.iau2006.org/mirror/www.iau.org/iau0603/index.html

[Sonia]

Pluto was automatically disqualified because its oblong orbit overlaps with Neptune's. It will now join a new category of "dwarf planets".

What does it matter? It still orbits the sun!

So what happened to this?
http://news.bbc.co.uk/1/hi/sci/tech/4795755.stm

[Sonia]

http://www.space.com/scienceastronomy/060824_planet_definition.html

[glenc]

It will be much easier to see all the planets now.
I have seen Pluto a few times and it was hard to find.
No need to tick it off now there are only 8.

[spacezebra]

Hi Sonia

I agree, it still orbits the sun! (the more the merrier)

Cheers Petra

[cometcatcher]

It's the end of the worlds as we know it!

I can hear Clyde Tombaugh turning in his grave. They never had the guts to do it when he was alive.

I never did see it when it was a planet. Oh well too late now.

[Rodstar]

This whole debate leaves me a little cold. We are only talking about labels and pigeon holes.

[[1ponders]]

Thank heavens the IAU has finally come to it's senses, or rather those voting have. What a ridiculous set of naming proposals, determining a planet simply on it's shape. Bah.

[acropolite]

I don't agree, after all pluto IMO is more a planet than say Jupiter or Saturn. We could stand on earth and the other rocky planets but not on the gas giants?? Really pluto has more charactersitics in common with earth as a planet than any of the jovian planets; to simply characterise a planet by size is short sighted.

[spacezebra]

Totally agree, with your analysis of the situation.

What are they going to do with the "New Horizons" mission - turn around and come home now that Pluto is no longer a "major" planet.

Cheers Petra

[iceman]

heh, good point Petra.

[hogly52]

I can handle the decision of the IAU, it at least has established a standard and definition for future discoveries. But I find it annoying that the ABC online news had to include the views of an astrologer into its reporting of a science activity. :mad2: :shrug:

Cheers,

Graeme

[iceman]

oh gawd I can imagine the astrologers are up in arms!

I agree though, that's very bad reporting by ABC.

[xelasnave]

Has anyone considered the impact on astrology?:D :P :lol:
alex

[anthony2302749]

I hear the new this morning, I suppose we now have to change the way we discuss Pluto. We will have to develop a completely new vocab to describe this object; words such as Minute, Tiny, Diminutive, Miniature, Petite, Undersize, Planetesimal and Dwarf all which are very apt. My favourite at the moment is “Diametrically challenged” it avoids the problem of being political incorrect.

[ThunderChild]

History shows that every time we think we understand our universe or even our solar system, some new discovery comes up which makes us completely rethink everything, because we were previously being a little simplistic or narrow. I think there are shades of that here - we've looked for a definition to include the classical 8 planets and leaves the others out. Pluto was always controversial.

Several problem appear here ;
(1) "Clear the neighbourhood around it's orbit". How vague is that? How far is one's neighbourhood? And how large do surrouding objects need to be before that neighbourhood is deemed "unclear"? Asteroids? Boulders? Pebbles? A few specks of dust?
I'm also assuming that things in orbit of the planet itself (eg moons, rings) are being excluded from being cleared since they are trapped by the planet itself.

Does this mean that if some event happened which brought some clutter into Earth's path of orbit that Earth would be demoted from planet status?

(2) "has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape" - I read this to mean that a round rock the size of my fist will be a planet if it's orbit is all alone.

Different materials require different pressures to bring them into a round shape. A small blob of water will very quickly form into a sphere. If it's "neighbourhood is clear", then it's a planet.

I think I'm missing some key pieces of knowledge about what these rules mean. Because it's all too easy to think up dozens of scenarios which would appear to break the definition.

I'm left a little unsatisfied by all this. While I completely bow to the superior astromonical knowledge of those concerned, on the surface this appears to be an extremely vague definition which has the hallmarks of needing to be updated in the future when something new forces us to confront the narrowness of our definition. Perhaps not in our solar system, but sometime we are going to start getting more and detail about other solar systems. I am convinced that our understanding is going to be completely blown apart as we learn more and more.

[Omaroo]

http://www.news.com.au/story/0,23599,20246532-2,00.html

The Australian, today.

What's going to happen to the good old "Pluto Pup"? :sadeyes:

[Gargoyle_Steve]

I find it incredible that the IAU sets up a comittee specifically to make a recommendation as to what should, and what should not, be considered a planet, the comittee drafts a set of guidelines, the IAU votes, and rejects the recommendations and actually goes in the opposite direction.

These guys act like politicians, not astronomers. Whether you agree or disagree with the final decision (I disagree, for what it's worth) the new rules still seem rather non-specific, and I'm sure the debate over this will rage for years to come.

When at school I learned the order of the planets by the mnemonic
"Most Volcanoes Erupt Mulberry Jam Sandwiches Under Normal Pressure"

I posted this back in March on these forums, but I'll post it here again.

With the official removal of Pluto as a planet I now propose this new one:
"Many Vulgar Earthlings Make Junior Satellites Unilaterally Nonexistent"

copyright Steve 2006

[h0ughy]

I agree, profound but true, when you have a moon almost as big as you why would you be a planet?

[Volans]

Alot of people have been saying this in the discussions I've seen online. Pluto does not overlap or cross Neptune's orbit. At all times there is a huge gap between Pluto's orbital path and Neptune's. The reason Pluto has been removed from the list of planets is due to the last criteria of the resolution. It does not have enough gravity to clear away it's local area. It's the same deal with Ceres; if Ceres were massive enough then its gravity would have either flung objects in the same orbit away or it would have collided with and absorbed them.

While I've often thought Pluto should not be a planet on scietific grounds, it should have retained its status for historical reasons. And as backup to that statement, I offer a host of scientifically inaccurate concepts that we all still use quite happily: the magnitude scale, stellar classes, the Quadrantid meteor shower, "seas" on the Moon, even my own nickname Volans which simply means "flying". Piscis Volans was the original name and is alot more sensible.

Well today I did the first school show without calling Pluto a planet. I had a group of rather bored grade 7's and 8's and they had no idea there was even a debate going on. I still mentioned Pluto however and gave them some of the facts and figures about it.

Peter.

[Dennis]

Now that is a very telling observation from someone in the educational community who is close to the coal face....how many people outside the astronomy community are really interested in this topic?

Not too many it would appear.

Cheers

Dennis

[h0ughy]

it doesn't raise the price of fuel, or milk or bread, or for that matter bananas:D ;) Because of that most couldn't care less:shrug:

[ving]

8 planets? much better than the other proposal of 12 plus anything else thats round and orbits the sun!!!

i am happy with eight, tho i'll miss that lil' bugger :)

[mickoking]

Pluto not a planet Booooooooooo ;) It will always be the 9th planet to me regardless of how its pidgeon holed.

[Volans]

School show update: I've just finished the second school show of the day and it was the second half of the first school group. We had about 60 in the first group (the ones who were bored) and the same number in the second group. The second group were alot more lively and though they did not know about the IAU debate, they did ask "Why is it no longer a planet?" So this is what I told them

"A bunch of astronomers had got together to find out what makes a planet a planet. We all know what makes a dog a dog - it has 4 legs and goes woof woof...a cat is a cat because it has 4 legs and goes meow...but what makes a planet a planet? The astronomers came up with three things and something needs to qualify in all 3 to be a planet. Pluto got the first two but not the third."

I did not tell them what the three things were and the good thing is they were interested enough that they asked about the criteria and I told them. I also told them that Pluto is now officially a Dwarf Planet but it's not a planet. They thought that was a pretty dumb thing to call it (out of the mouthes of babes!) and they gave a round of applause for Pluto to cheer it up..LOL. They were a pretty cool group.

Peter.

[Robert_T]

I must confess to being less that excited either way, despite a long interest in Astronomy. I doubt pluto cares, it's size, shape, mass and gravity etc hasn't changed. In any case it really shouldn't stop people referring to pluto however they see fit. One group of humans have elected to call Pluto other than a planet. So what. I still call chips, "chips" even if a lot of people call them "fries" ....

[ving]

potato. :)

[anthony2302749]

In that case would it be best to describe it as a diametrically challenged binary planetary system. :rofl:

[rogerg]

Thank goodness I got photo's of pluto earlier this year during the occultations, while it was still a planet!

I wonder if those photo's are worth money now because the are of "The planet Pluto", you can't get photo's like that anymore ya know! Maybe I should auction them on eBay :lol:

Roger.

PS - in case you couldn't tell, I find this whole debate entertaining and a little silly although I agree a clear definition is required.

[fringe_dweller]

well I am glad I did the now quaint and antiquated? 'visually observe all 9 planets in one night challenge' that the US S&T magazine used to regularly promote back in the 90's while they were all still planets :D

As someone has already said, its all about the anticipated rush of 'dwarf planet' planetisimals, planetoids, captured mega comets/Oort cloud/Kuiper belt/TNO's fringe dwellers whatever you call them :) that is surely coming with ever deeper imaging and probes ect. 100 000 AU all the way out to the far edge of the Oort cloud I assume? is that not filled with millions of possible dwarf planets then???




I remember at least one period in the '90's when Neptune was the outermost planet for a while - I cant remember how often that happens now?

they should just qualify planets by what ever fringe dweller can visually pick up in his homemade 8" dob??? :D

[fringe_dweller]

OT kinda - btw did everyone hear that joke going around after announced they planned to name 2003 UB313 'Xena'

'that just confirms our suspicions that astronomers are fundamentally just a bunch of horny geeks' ;)

[sheeny]

I was hoping they'd go the other way and we could name planets after the rest of Disney's characters... Mickey, Donald, Goofy... Hewie, Dewie and Lewie...
:rofl:
What does it matter really? Pluto hasn't changed.

I don't know what affect Pluto has on horoscopes, but have you thought about the impact us meddling astronomers may have inadvertently had given this decision?
;)

Al.

[[1ponders]]

Hey that's right. I may have the only authentic images of Ceres in it's short planetary career. Wow.



I wonder if channel nine wants them and how much they would pay :lol:

[jjjnettie]

All my books are out of date now. A splendid excuse to buy more stuff!

[Starkler]

Phew ! I got to observe Ceres during its short planetary career.
Hands up who can say they have observed ten planets ;)

[mickoking]

As a Libra with out Pluto I'm screwed. Please, please make Pluto a planet again otherwise my life is down the drain.



:rofl:

[asimov]

I'm with you on this one :thumbsup:

I couldn't give a stuff what anyone calls it....I'll be calling it the 9th planet & thats that!! :P

[gaa_ian]

Poor Pluto :sadeyes:
But look on the bright side, when people ask to be shown the 9th planet, we don't have to try & find it :thumbsup:

[AstroJunk]

So, from what I've read, Pluto is relegated because it has failed to clear Neptune out of it's orbit. That means that Neptune also fails to be a planet because it has failed to clear Pluto out of it's orbit. So we're down to 7 planets in a puff of logic. Poor Neptune:sadeyes:

More Vigorous Examination Make Jury Scientists Useless ...

[Ric]

In the year 3006 when Pluto is voted the best Exclusive Off World Ski Resort for the 6th year straight, will anyone really care what the boffins decided on today.

[[1ponders]]

Amen to that AJ

[Jackson42South]

The International Astronomy Union could not have been any meaner
Reclassifying planets because their orbits are less cleaner.

Little Pluto, once a mighty planet, now classified as a dwarf
You failed to sweep you orbit clean, now just a planet list cast off.

So band together all dwarfs, including little Xena
What you need to become a Planet now is an orbital vacuum cleaner.

:(

[astro_nutt]

With the study of planet formation for goodnes knows how long..I've always wondered about Pluto..the closest to our Sun are rich in iron..further out..iron, silica, rocks..further still gas...and still further..gas, ice..then Pluto..rocks and ice!..and for some it has been a puzzle on how this should be?...was Pluto an inner world at one time then flung out from coliding with another??..(and maybe smacked into Uranus on the way!)..then settled into orbit?...but even if it's not classed as a planet..I will still regard it as the ninth world from our Sun!!

[fringe_dweller]

:rofl: @ jackson42south, nice one :thumbsup: they are a bunch of bullyboys and killjoys arent they beating up on the little planets like that BOO!

great thread everybody, keep 'em coming - Asi and others of the same sentiment - I agree it will always be the 9th planet to me :thumbsup:

[fringe_dweller]

whats this!! - we've moved on already?? wheres the momentum of the rage against the fascist bully boys of the IAU gone - spent already??? geez ya pussies, we are getting walked all over here gggrrrrrr

[Miaplacidus]

Personally, I think we should go back to the original meaning. A planet (from the Greek word for "wanderer") must fulfil the following:

1.) it is an easily seen naked eye object that can be easily mistaken for a star
2.) repeated observation by an ordinary observer clearly demonstrates that it moves against the background stars.

After all, planets have been around a lot longer than the IAU.

[netwolf]

I agree Miaplacidus this is the orgin of the word and so it should remain that way.

One would think ther are more important matters than symantics. Anyway why not use something like what they introduced in Startrek (Trekkie alert), M-Class , J-Class etc.

Regards

[glenc]

Astronomy Picture of the Day


Eight Planets and New Solar System Designations

2006 August 28

http://antwrp.gsfc.nasa.gov/apod/astropix.html

An image for those that missed it

[Sausageman]

Who gave the 420 odd members of the IAU the right to determine what is and what is not a planet. Not very Democratic is it! It orbits the Sun doesn't it, who cares if it hasn't swept up the debris in the orbit.
Surely there are hundreds of thousands of professional Astronomers and millions of us around the World, why didn't we get a say!!!!!
Why wasn't there a WWW referendum of Astronomers, professional and Amateur alike, and Teachers.
Does this mean that all the extra solar system planets discovered over the last few years cannot be ratified because it can't be proven that they have swept up all the debris in their orbits?
This would mean that all the research and and papers written on the subject are a load of you know what........

I rest my case.

Mike

[mickoking]

420 members of the IAU voted not to call Pluto a planet anymore, so what. To me and many others Pluto remains a planet. The universe isnt owned by a handfull of Astronomical bureaucrats ;)

[fringe_dweller]

well, after reading just some of the thousands of forum and forum type pages on the net on this hot topic, (including here) I have to say this has been one of the most fascinating and sometimes hilarious discussions regarding popular astronomy I have ever seen.
After all, surely the now defunct 70 odd yr old fact 'the solar system has 9 planets orbiting the sun' and third rock from the sun and all that - would be one of the few astronomical facts that has grown larger and passed and been accepted into the collective human landscape and soul, sentient view of our place in the scheme of things ect., and maybe the nomenclature rights are no longer the property of scientists and the IAU?.

And it is now redundant!! - or some say at least temporarily?, but obviously has had absolutely massive media coverage anyway (whoops?), declaring it permanent and sanctified, so maybe too late? to reverse in the publics mind. And further playing around with it would possiby damage or reinforce the wider public's sometimes negative? image of the astronomy game, and the people who play it? Its madness to toy with their publics affections like that!
I cant believe the IAU couldnt of shown a little bit more sensitivity, just get around the reclassification/definition of a planet without coming across as the grinch's that stole christmas - and making all the little kids cry -
and do it on the sly, after all does it really matter to science that much does it? They just give them some sort of sub classification, which we already have - I mean one good example, one of the many great posts I have read, pointed out that with that sort of logic Jupiter should be called a dwarf brown dwarf then (hehe)
And btw Phil I agree with your point, why banish and put down a planet coz its mainly ice?, with that logic the giant gas planets are only gas (and pressurised liquid form gas) after all? (could create a new gas planet out this debate? ;) ) and you cant play footy on them, ie: thats not a planet, this is a planet :D
Also as I read somewhere (BAUT i think) the other classical planets arent even planets/worlds in the biblical, garden of eden sense of the word either :P ask an ID'er

I have to mention one very funny one I read out there, its something along the lines of ... NEWSFLASH: the PAU (plutonian astronomical union) in retaliation, has just reclassified earth as now no longer a planet, but merely just one of the inconsequental inner Trans Jovian Rocky Belt Objects or TJ RBO's (hope I got thats kinda right - as I cant find it now - bugga) :rofl:
too many funny ones out there (and in here to) to mention although I would like to :)

EDIT: almost forgot - Ceres seems to be the big winner out this - after 150 years as an asteroid, its promoted permanently to a dwarf planet!! congrats are in order!?
ps to those who said it was briefly a real planet there for a while, I missed that one? when was it a planet?

[ving]

ceres :party:

congrats dude! :D

[mickoking]

Dwarf planet, what is that? A Red or White Dwarf star is still a star so by the same logic a dwarf planet is still a planet.

[glenc]

If they call Pluto a planet they have to call 2003 UB 313 a planet too.
Do we want that?
It would make it really hard for us to see all the planets.
It was hard enough to see Pluto.
And what if they find more like UB?

[astroron]

Why carn't we have lot's of planets?:shrug: A planets is a planet however big it is. The Sun is a sub dwarf star, but is still a star:P
As one who has seen Pluto :astron: I still count myself as seeing 9 planets, counting the one I am standing on:thumbsup: Go Pluto:jump: :jump: :jump: :jump:

[mickoking]

I would consider 2003U313 a planet. 10 planets makes more sense than 8 :thumbsup:

[glenc]

UB is mag 18.9.
I don't want it as a planet!!!

[mickoking]

Here is something interesting I found in one of my old Astronomy books; Worlds without end, H Spencer Jones (The Astronomer Royal of the day) Printed in 1938. It seems Pluto's identity as a planet has always been a tenuous one.

[glenc]

Astronomers fight to restore Pluto's planet status

http://www.abc.net.au/news/newsitems/200609/s1731323.htm

http://www.ipetitions.com/petition/planetprotest.

Its not over yet??

[CoombellKid]

Easy they'll just format the CD-Rom wif all our names on it, for those
that did get their name on it. And change the title to Dwarf Planet :)

Actually I think it is great to finally have Pluto classified, I think it will
always be called pluto until they bread all the die hards out.... Kinda
like the Liberal Party lol, I thought it was even more stupid to vote
on Charon as a planet. But maybe that wasn't explained to me properly

regards,CS sunny days

Rob

[cahullian]

The decision on Pluto was long over due and as far as I'm concerned good riddance to bad rubbish.By time we finish looking at our solar system we will probably find numerous objects as big or bigger than our little friend Pluto.

[Gargoyle_Steve]

The whole sticking point in the decision to demote Pluto was made out to be the fact that it has not cleared it's orbital path of other bodies.

So why then does the IAU not likewise demote Jupiter from Planet status when it has 1108 known and cataloged "other bodies" sharing it's orbital path (I don't mean crossing it, I mean sharing it - they travel along the same path!) and preceding Jupiter at the L4 Legrangian point, and another 718 following Jupiter at the L5 point? I refer to the Trojan asteroid group(s).
http://en.wikipedia.org/wiki/Trojan_asteroid

Not what I would call a "cleared" orbit.

Apparently Neptune also has similar bodies sharing it's orbital path, and Mars may as well.

Are we now down to 5 planets in our solar system after the IAU demotes these 3? I don't think so.

Many members of the IAU simply did not want Pluto to be considered a planet, and in their rush to try and find a reason to justify it's demotion thay have become sloppy, and that's why there is such discord amongst the astronomical community.

[fringe_dweller]

thats a glaring contradiction/complication that the IAU seems to have glossed over - rather strange isnt it Steve ;)

[ving]

umm... including pluto which crosses over neptunes path.:screwy:

[Volans]

The confusion is still there amongst the public and the school kids. In fact it has brought to my attention the general lack of understanding in the upper school level (grade 7+) of gravity. The whole idea of something having enough gravity to haul itself into a sphereoid (hydrostatic equilibrium) is quite foreign to these students - but that is another matter.

It seems that a lot of children identify quite strongly with Pluto and they are feeling very put out because it has been seen to now be excluded from the Solar System. I can tell them 'till I'm blue in the face that it is still part of the Solar System, it's still called Pluto, it's still the same size it was 2 months ago etc. etc. Not good enough apparently.

One child thought Pluto had escaped the Solar System, another asked "What can we do to save Pluto?" (I replied with "Why does it need to be saved?"), yet another child insisted there were 12 planets in the Solar System and alot of children ask "What happened to the three new planets they found?".

Two things are going on here. The first is the atrocious apathetic manner in which the various media have handled this story. When there was the prospect of 12 planets they were all on to it but when it dropped to 8.... it was buried close to the story about Gilbert the Goldfish saves family from armed intruder (I'll never annoy fish again!). The second thing is the wording of the IAU resolutions. Basically it is poorly worded and has resulted in bad science.

Science is supposed to clarify not cause confusion.

Peter.

[robagar]

just to cap off how daft that decision is, Earth hasn't cleared it's orbit either - there are at least four corkscrew asteroids (http://science.nasa.gov/headlines/y2006/09jun_moonlets.htm) whizzing round with us...