Pluto loses status as a planet

[Dark One]

Astronomers meeting in the Czech capital have voted to strip Pluto of its status as a planet.

About 2,500 experts were in Prague for the International Astronomical Union's (IAU) general assembly.

Astronomers rejected a proposal that would have retained Pluto as a planet and brought three other objects into the cosmic club.

Pluto has been considered a planet since its discovery in 1930 by the American Clyde Tombaugh.

The vote effectively means the ninth planet will now be airbrushed out of school and university textbooks.

The decision was made at a meeting of the International Astronomical Union (IAU) in the Czech capital Prague.

"The eight planets are Mercury, Earth, Venus, Mars, Jupiter, Saturn, Uranus and Neptune," said the IAU resolution, which was passed following a week of stormy debate.

The IAU's proposal to raise the number of planets in the Solar System to 12, adding the asteroid Ceres, Pluto's "moon" Charon and the distant object known as 2003 UB313, met with opposition.

Pluto's status has been contested for many years as it is further away and considerably smaller than the eight other planets in our Solar System.

Since the early 1990s, astronomers have found several other objects of comparable size to Pluto in an outer region of the Solar System called the Kuiper Belt.

Some astronomers believe Pluto belongs with this population of small, icy "Trans-Neptunians", not with the objects we call planets.

Allowances were once made for Pluto on account of its size. At just 2,360km (1,467 miles) across, Pluto is significantly smaller than the other planets. But until recently, it was still the biggest known object in the Kuiper Belt.

That changed with the discovery of 2003 UB313 by Professor Mike Brown and colleagues at the California Institute of Technology (Caltech). After being measured with the Hubble Space Telescope, it was shown to be some 3,000km (1,864 miles) in diameter, making it larger than the ninth planet.

[Rilla]

Well, there goes "My Very Excited Mother Just Saw Uncle Ned's Pigs"...

*mourns the loss of pigs*

[Min]

Huh. So what will it's official status be? Asteroid?
I guess they have a point, but still...it'd be like saying "Oh, we aren't going to recognise that Tasmania is a state any longer, it's just too small to bother about".
It doesn't mean it isn't there, and isn't a part of Australia as a whole...

And Charon can't be called a planet...it's orbiting Pluto. It's a bloody moon.

[Dragon]

*agrees with Min and Rilla*
Now i have...My very educated mother just showed us nine.........WHAT??!!!
Now it seems my mother is not so educated because there are only eight planets.
So what if pluto is a little small....its orbiting the sun isn't it?? And they're dubbing it a dwarf planet (so its still a planet is it not??) I'm sure a dwarf star is still a star.
So in the world of Kirsty (and it exsists!) Pluto will still be considered a planet.

[Arctic Firefox]

Poor Pluto. I'm sure he'll be howling in his kennel for weeks to come.

[Rushton]

Well it's still a planet in my book

- then again our set of encyclopedias still has the Berlin Wall and the big red region known as the USSR...

[Dameon]

Pluto IS a planet!

Don't worry Pluto! We still love you!

[Kella]

Well if they take away pluto, then all the planets will end at uranus!

[muzz]

WELL THE IAU ARE NOW THE DUMBEST PEOPLE EVERE

[Kaylan-R]

That is incredibly ridiculous. I mean, its just like what Min said, but Tasmania is a state, so why isn't it the same as Pluto? Though I guese it's like saying Pumpkin is a vegetable when it's actually a fruit. But we all say it's a vegetable!
Its barbaric, now we'll have to change everything!

[Kella]

Sry I've got my facts wrong! neptune is the last planet! It's so stupid its like ^^ they said. It's so stupid! Everone learnt about the NINE planets not eight!

[muzz]

SORRY ABOUT THE WEIRD NAME REMARK elspethinnle BUT IM JUST ANNOYED

[Dark One]

Ok, but there's no need to shout (typing in caps is shouting on forums etc)

I shall still be classing Pluto as a planet, despite what the IAU say.

On an interesting note, the Mayans knew of 10 planets in our Solar System

[Kaylan-R]

Mayans?

[Deleted]

How come everyone else was taught a planetary mnemonic that made sense? My grade three teacher taught us: "My Very Energetic Ma Just Sat Up Nee Pa" which sounded like he started out with good intentions at making a memorable sentence, but just gave up towards the end. Although I can't really complain because my Periodic table mnemonic was "High Heels Like Betty Bought Can Not Occupy French Neanderthals." ;D

"My Very Excited Mother Just Saw Uncle Ned's Pigs" sounds much better. And I'm not too bothered about the Pluto thing, science is always changing. Continental drift was only theorised in the past 50 years, I think, so just imagine the educational storm that would have raised when it first came up. But there is something lovely and mystical about the number nine (3 by 3 and all that). 8 doesn't seem as 'complete' somehow.

[Dark One]

Pluto vote 'hijacked' in revolt


A fierce backlash has begun against the decision by astronomers to strip Pluto of its status as a planet.

On Thursday, experts approved a definition of a planet that demoted Pluto to a lesser category of object.

But the lead scientist on Nasa's robotic mission to Pluto has lambasted the ruling, calling it "embarrassing".

And the chair of the committee set up to oversee agreement on a definition implied that the vote had effectively been "hijacked".

The vote took place at the International Astronomical Union's (IAU) 10-day General Assembly in Prague. The IAU has been the official naming body for astronomy since 1919.

Only 424 astronomers who remained in Prague for the last day of the meeting took part.

An initial proposal by the IAU to add three new planets to the Solar System - the asteroid Ceres, Pluto's moon Charon and the distant world known as 2003 UB313 - met with considerable opposition at the meeting. Days of heated debate followed during which four separate proposals were tabled.

Eventually, the scientists adopted historic guidelines that see Pluto relegated to a secondary category of "dwarf planets".

Drawing the line

Dr Alan Stern, who leads the US space agency's New Horizons mission to Pluto and did not vote in Prague, told BBC News: "It's an awful definition; it's sloppy science and it would never pass peer review - for two reasons.

"Firstly, it is impossible and contrived to put a dividing line between dwarf planets and planets. It's as if we declared people not people for some arbitrary reason, like 'they tend to live in groups'.

"Secondly, the actual definition is even worse, because it's inconsistent."

One of the three criteria for planethood states that a planet must have "cleared the neighbourhood around its orbit". The largest objects in the Solar System will either aggregate material in their path or fling it out of the way with a gravitational swipe.

Pluto was disqualified because its highly elliptical orbit overlaps with that of Neptune.

But Dr Stern pointed out that Earth, Mars, Jupiter and Neptune have also not fully cleared their orbital zones. Earth orbits with 10,000 near-Earth asteroids. Jupiter, meanwhile, is accompanied by 100,000 Trojan asteroids on its orbital path.

These rocks are all essentially chunks of rubble left over from the formation of the Solar System more than four billion years ago.

"If Neptune had cleared its zone, Pluto wouldn't be there," he added.

Stern said like-minded astronomers had begun a petition to get Pluto reinstated. Car bumper stickers compelling motorists to "Honk if Pluto is still a planet" have gone on sale over the internet and e-mails circulating about the decision have been describing the IAU as the "Irrelevant Astronomical Union".

'Inconvenient arrangements'

Owen Gingerich chaired the IAU's planet definition committee and helped draft an initial proposal raising the number of planets from nine to 12.

The Harvard professor emeritus blamed the outcome in large part on a "revolt" by dynamicists - astronomers who study the motion and gravitational effects of celestial objects.

"In our initial proposal we took the definition of a planet that the planetary geologists would like. The dynamicists felt terribly insulted that we had not consulted with them to get their views. Somehow, there were enough of them to raise a big hue and cry," Professor Gingerich said.

"Their revolt raised enough of a fuss to destroy the scientific integrity and subtlety of the [earlier] resolution."

He added: "There were 2,700 astronomers in Prague during that 10-day period. But only 10% of them voted this afternoon. Those who disagreed and were determined to block the other resolution showed up in larger numbers than those who felt 'oh well, this is just one of those things the IAU is working on'."

E-voting

Professor Gingerich, who had to return home to the US and therefore could not vote himself, said he would like to see electronic ballots introduced in future.

Alan Stern agreed: "I was not allowed to vote because I was not in a room in Prague on Thursday 24th. Of 10,000 astronomers, 4% were in that room - you can't even claim consensus.

"If everyone had to travel to Washington DC every time we wanted to vote for President, we would have very different results because no one would vote. In today's world that is idiotic. I have nothing but ridicule for this decision."

He added that he could not see the resolution standing for very long and did not plan to change any of the astronomy textbook he was currently writing.

But other astronomers were happy to see Pluto cast from the official roster of planets. Professor Iwan Williams, the IAU's president of planetary systems science, commented: "Pluto has lots and lots of friends; we're not so keen to have Pluto and all his friends in the club because it gets crowded.

"By the end of the decade, we would have had 100 planets, and I think people would have said 'my goodness, what a mess they made back in 2006'."

Shaking hands

Robin Catchpole, of the Institute of Astronomy in Cambridge, UK, said: "My own personal opinion was to leave things as they were. I met Clyde Tombaugh, who discovered Pluto, and thought, it's nice to shake hands with someone who discovered a planet.

"But since the IAU brought out the first draft resolution, I was rather against that because I thought it was going to be very confusing. So the best of the alternatives was to keep the eight planets as they are, and then demote Pluto. I think this is a far superior solution."

The need for a strict definition was deemed necessary after new telescope technologies began to reveal far-off objects that rivalled Pluto in size.

The critical blow for Pluto came with the discovery three years ago of an object currently designated 2003 UB313. Discovered by Mike Brown and colleagues at the California Institute of Technology, 2003 UB313 has been lauded by some as the "10th Planet".

Measurements by the Hubble Space Telescope show it to have a diameter of 3,000km (1,864 miles), a few hundred km more than Pluto. 2003 UB313 will now join Pluto in the dwarf planet category.

Mike Brown seemed happy with Pluto's demotion. "Eight is enough," he told the Associated Press, jokingly adding: "I may go down in history as the guy who killed Pluto."

PLUTO - A 'DEMOTED PLANET'

• Named after underworld god
  
• Average of 5.9bn km to Sun
  
• Orbits Sun every 248 years
  
• Diameter of 2,360km
  
• Has at least three moons
  
• Rotates every 6.8 days
  
• Gravity about 6% of Earth's
  
• Surface temperature -233C
  
• US probe visits in 2015
  

[me]

I feel so sorry for pluto! How would you like it if suddenly someone came up and said "No, I think you're too small to be a person.' How would you like it? It's now officially a dwarf-planet, which according to scientists does now constitute an actual planet. And I think that's very PC (politically incorrect btw). Shouldn't it be a vertically-challenged planet? Although, a planet or dwarf-planet wouldn't be vertically challenged but sizecally challenged. Not that that's a word. My Educated Mother Just Showed Us Nine. My Educated Mother Just Saw Uncle Ned. At least the last one makes sense. Poor Pluto. I'll always love you! Even if you are no longer a planet but a dwarf-planet which is apparently different from a planet. Using their logic dwarves are no longer people. New Zealand should be too small to be a nation and can just join on to Australia. Just proves how illogical they are being. They should have added planets that were equal in sixe with Pluto, not taken its planet title away...

[scruffy]

The mnemonic we learnt was "My Very Elderly Mother Just Sat Up Near Pluto" which always seemed a little odd (but not as odd as the 'sat up nee pa'...)

Science is full of crazy mnemonic...

[Roland]

Yeah. You guys should hear the mnemonic for the cranial nerves.

Well, at least you could, but it isn't to be repeated in polite company (I've never forgotton them since though! Although patients possibly wonder why I'm blushing as I do their neurological examination ).

Anyways, I hear a nice theory about poor little Pluto. You know Pluto's orbit crosses Neptune's right? Want to bet that Neptune's gone running to his Mummy, "Mum, he keeps coming in my room!", and now poor old Pluto's been demoted to Moon.

Neptune's just a whinger. That's the problem

[Dark One]

Lol! That's good Turks. Maybe we should write a saga of the planets?

[Kella]

I think the IAU have to be the biggest group of Dum-Dums I have ever heard of. They wanted to count an asteroid as a planet! Just how stupid can you get? 9 is a better number for the number of planets than 8! It just doesn't seem as complete somehow... And how are we supposed to count a planet that has only just been discovered and doesn't even have a proper name but one like 2003 B303 or something like that?

[HeartoftheDarkness]

Grr, I can't stand this!
They can't just take away a planet! It's insane!

All I can think about right now is, us all in 30-40 years, 'in my day, we had nine planets...', and our grandchildren 'wow! no way! =O'

[Fuil Dearg]

i agree with HeartoftheDarkness.

[Lauren Hedgehog]

Scruffy said: Science is full of crazy mnemonic...

Which is very very true! We were taught the order of Kingdom, Phylum, Class, Order, Family, Genus, Species as : Kinky Policeman Can Often Fancy Gay Sargents The Med students ones are much worse though!

[DragonMornir]

I cant beleive they did this!! everyone over the age of 7 or 8 knows of 9 planets!!! thats the damn majority of the world!!!
And i agree, when we are older people will go... there was 9 planets... No way!!!. Its just stupid. they cant go changing what has been dictated since it existed....over 70yrs..... just makes everyone else look stupid for not seeing it sooner. And its just not right. only 4 % got to vote?? they cant say thats going to stay surely....

My Very Elderly Mother Just Sits Under Neath ...... underneath what dammit!!!

I know what you mean Turks.... the one i have is : On Occassions Our Trusty Trunks Act Funny.Very Good Vehicle Any How.