Astronomers to vote on potential new planets

[BWF89]

The International Astronomical Union (IAU) has offered up a new definition of the word "planet" that could potentially increase our solar system's nine planets to at least twelve. According to the proposed definition, "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 in orbit around a star, and is neither a star nor a satellite of a planet." Roughly speaking, the former includes objects over 5 x 1020 kilograms (1/12,000th of Earth's mass) and 800 kilometers in diameter, but all borderline cases would require confirmation by observation of their shape.

According to this new definition, Ceres (an asteroid in the asteroid belt, between Mars and Jupiter), 2003UB313 (an astronomical object beyond Pluto which has previously been called the tenth planet), and Pluto's moon Charon may be dubbed planets. A dozen other candidates, like Sedna, Orcus, Quaoar, 2003 EL61 etc., along with the asteroids Vesta, Pallas and Hygiea are awaiting evaluation by the IAU.

The draft resolution also introduces the term "pluton", which refers to a growing subcategory of planets that have orbits around the sun that take at least 200 years to complete - effectively this will mean planets that orbit beyond Neptune. Plutons differ from classical planets: their orbit is highly tilted, eccentric and not circular, which suggests they have a different origin, the main reason why astronomers are interested in them.

The word "planet" comes from the ancient Greek word for "wanderer", because it was known in ancient times that certain lights in the sky moved in relation to other stars. However, since then no formal definition of the word planet was agreed upon. With the advent of powerful telescopes on the ground and in space, knowledge about heavenly bodies became more complex, stressing the need for unambiguous definitions. The issue came to a head in 2005 with the discovery of the trans-Neptunian object 2003UB313 (unofficially termed Xena by it's discoverer, Michael E. Brown). 2003UB313 is a body larger than the smallest accepted planet, Pluto.

The suggested definition is not universally popular: some astronomers would like to draw the line at Neptune, and wouldn't classify icy dwarfs like Pluto as a planet, but as a trans-Neptunian object (similar to the plutons in the draft resolution) part of the Kuiper belt. Robin Catchpole, from the Institute of Astronomy, Cambridge, said in an interview: "The public are very clear about what they understand by "planets". Those are the big, dominant bodies in the Solar System that we're all familiar with, the eight - or nine if you include Pluto. I think including more is going to add confusion to the public, but not really be particularly useful for astronomers."

Pluto is now being considered to be moved off the list of classical planets, but as the prototype of the new plutons category. The ninth planet (as it is termed, but maybe not for long), discovered in 1930, is a curiosity among planets for more than one reason: because Charon is so big in comparison, both are considered twin planets by some.

The current proposal is the result of two years work of the Planet Definition Committee of the IAU, which is responsible for the naming of astronomical objects. The 26th IAU General Assembly in Prague plans to vote on the proposal on Thursday, August 24 of 2006. When asked if he was confident the proposal would get the necessary two thirds of the votes, Professor Owen Gingerich, Chair of the IAU Planet Definition Committee, replied: "I'm sure it will be controversial to those with a stake in some other solution, but I hope we will get an overwhelming endorsement."
http://en.wikinews.org/wiki/Astronomers_to_vote_on_potential_new_planets

[Dev'olution]

Interesting stuff.. so at the end of the day, how many planets will be in our system?

[professor_chaos]

As far as I'm concerned they can call them potatos. It doesn't have any affect on reality. IMO these smart people should spend their time doing something more important. ;)

[jason.b.c]

As far as I'm concerned they can call them potatos. It doesn't have any affect on reality. IMO these smart people should spend their time doing something more important. ;)

What so your not happy with the way your tax dollars are being spent..??

Isn't it great..??

[BWF89]

Pluto is nolonger a planet.

Full story: http://en.wikinews.org/wiki/Pluto_loses_planet_status

[richbarna]

Well, as long as they don't try and convince me that the moon ISN'T made out of cheese, they can call a rock a planet if they want.
I agree with other members, can't governments spend money feeding people on this particular rock first ?!

[Vorian]

Well, as long as they don't try and convince me that the moon ISN'T made out of cheese, they can call a rock a planet if they want.
And if Pluto is made of planet, isn't it a planet? Earth, Venus, Mars, even Saturn are made of planet, they are all planets. Pluto is made of planet but its a "dwarf" planet! That is bull $#!* !!!!
They shouldn't insult dwarves in such a manner!

Uranus should have always been the End of our solar system.

[cstudent]

I think they should change it's name to Ork.

[DoktorSeven]

Good. Now let's get rid of that silly so-called planet "Earth." How can it be a planet when it's the center of the universe???

(No, I'm not serious. Yes, I'm for the reclassification of Pluto. About freaking time.)

[curuxz]

And if Pluto is made of planet, isn't it a planet? Earth, Venus, Mars, even Saturn are made of planet, they are all planets. Pluto is made of planet but its a "dwarf" planet! That is bull $#!* !!!!
They shouldn't insult dwarves in such a manner!

Uranus should have always been the End of our solar system.

Made of planet....wtf?

Earth is made of rock...is a planet, the gas giants are made of gas...no rock.....still a planet. what the hell is this 'made of planet' stuff about.

Btw I agree with their choice, pluto is only slightly bigger than charon and smaller than X so im glad they have demoted it.

[mostwanted]

Haha, "made of planet", that made my day :D

Pluto is made of ice by the way, as is comets, but those aren't called planets even though they orbit the sun.

[Miguel]

And I thought that Jupiter was made of solid metallic hydrogen...

[Vorian]

Pluto is made of ice by the way, as is comets, but those aren't called planets even though they orbit the sun.

Its not the size of a planet that matters, its the heart. Pluto's got alot of heart.

Hang in there little guy, your gonna be o.k.

[Vorian]

Made of planet....wtf?

Earth is made of rock...is a planet, the gas giants are made of gas...no rock.....still a planet. what the hell is this 'made of planet' stuff about.

Btw I agree with their choice, pluto is only slightly bigger than charon and smaller than X so im glad they have demoted it.

But it is round, and that is important. And "wtf" is not a planet, its a moon.

[Spacecaptain]

But it is round, and that is important. And "wtf" is not a planet, its a moon.

roundness was not enough as a factor for "planethood". there are spherical asteroids made up of rubble and dirty snow that measure around 500m diameter. i feel a liitle doubtfull that those should become fullfleged planets just because they are pretty round. we would end up having a solar system with hundreds of planets in it.

the material a planet is made from is not important, be it hydrogen, water, rock or spaghetty.
what they have decided to add as a criteria is the fact that the body has to be the dominating one by far in it's region. This is where Pluto fails, as it crosses Neptune's orbit.

as for the issue on spending money on this being useless... maybe this is just as stupid as spending money in the mathematics field, or philosophy, and what's the use of litterature, anyone?.... do you really think fundamental research to be such a "useless" endeavour? maybe some have to revise their definition of usefullness.

[BWF89]

The International Astronomical Union is a collection of astronomers from around the world that get together to discuss things space related. It's supported by any government as far as I know.

[Vorian]

The International Astronomical Union is a collection of astronomers


Which I am a member of. The facts were taken completely out of this desicion. 1. Its round and in space. 2. Its made of Planet, that is very important. 3. It has a cool name "Pluto".

[givré]

Which I am a member of. The facts were taken completely out of this desicion. 1. Its round and in space. 2. Its made of Planet, that is very important. 3. It has a cool name "Pluto".
Could you define more precisly your definition of "is made of planet"? 8)
Also, pluto is as round as a potato, just like a lot of asteroid, so it's not really a criteria.

[Mathiasdm]

Which I am a member of. The facts were taken completely out of this desicion. 1. Its round and in space. 2. Its made of Planet, that is very important. 3. It has a cool name "Pluto".
The facts weren't taken out. They created a reasonable definition. The bad points about it:
-It's limited to our solar system.
-'nearly round' is not defined any further. How round does it have to be?
-'the neighbourhood' has not been defined any further. How large should the cleared area be?


RESOLUTION 5A
The IAU therefore resolves that "planets" and other bodies in our Solar System be defined into three distinct categories in the following way:

(1) A "planet"1 is a celestial body that (a) is in orbit around the Sun, (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) has cleared the neighbourhood around its orbit.

(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2 , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects3 except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".

[givré]

-You remplace sun by every stars that you want and you have your definition.
But it's already difficult to found planet smaller than jupiter out of the system solar, so before they found something like pluton...
-nearly round = hydrostatic equilibrium, no need more.

[Mathiasdm]

-You remplace sun by every stars that you want and you have your definition.
But it's already difficult to found planet smaller than jupiter out of the system solar, so before they found something like pluton...
-nearly round = hydrostatic equilibrium, no need more.
-That's just the point. That's what they should have done, but they didn't. So I think that should be changed.
-Correct. Sorry about that:p

[TravisNewman]

its amazing how many people here aren't getting some people's jokes :)

Anyway, I think it should be a planet because, well, it's been a planet for so long. Pluto's planethood was ingrained into my brain when I was in Kindergarten. This is life shattering. ;)

[richbarna]

its amazing how many people here aren't getting some people's jokes :)

Anyway, I think it should be a planet because, well, it's been a planet for so long. Pluto's planethood was ingrained into my brain when I was in Kindergarten. This is life shattering. ;)

And they named the Disney dog after it for chrissakes !!!! Pluto stays !
Also, if we suddenly get a bunch more planets, the sci-fi films will get better. Why do the spaceships always have to come from Mars ?(Mars Attacks, War of the worlds).

Maybe they could start a thread here on suggested planet names, that would be cool.

I vote for planet Linux, anybody else want to be a Linuxian ? :D

[%hMa@?b<C]

now, why did poor little pluto get kicked out of club planet?
I loved pluto!!!

[mostwanted]

When space tourism starts, Pluto will get this tagline:

"I can't believe it's not a real planet!tm"

[BWF89]

http://www.geekculture.com/joyoftech/joyimages/861.gif

[ComplexNumber]

As far as I'm concerned they can call them potatos. It doesn't have any affect on reality. IMO these smart people should spend their time doing something more important. ;)
i think i agree with that. they're often called the "intelligentsia", but they are always inevitably very dumb and have very little wisdom about life, society, or people. similar minded people spent several million euros a few years ago debating if the scottish kilt is womensware or not :grin:

[richbarna]

i think i agree with that. they're often called the "intelligentsia", but they are always inevitably very dumb and have very little wisdom about life, society, or people. similar minded people spent several million euros a few years ago debating if the scottish kilt is womensware or not :grin:

I hear they just got a grant to study the Roman Toga :D

[Erik Trybom]

I laughed so hard at this image: http://www.city.se/TT_img/51849a.jpg

I can really see all the dead serious scientist getting angry at each other over this infected topic and when it comes to voting they look at each other to see how the others vote. Reminds me of the student council at my university where people engage in heated discussions over small issues that no one cares about.

If you can't see the fun in this, you're probably one of them.

[Biltong (Dee)]

My Very Earthly Mother Just Sat Upon Neptunes Pluto.

Pluto HAS to be called a planet. What else is myveryearthlyma gonna sit upon?

[Spacecaptain]

its amazing how many people here aren't getting some people's jokes :)

Anyway, I think it should be a planet because, well, it's been a planet for so long. Pluto's planethood was ingrained into my brain when I was in Kindergarten. This is life shattering. ;)

i like life shattering changes like theese! it keeps you on your toes! :D
science is not engraved in stone, it evolves!

1) i see roundness as a good criteria, though not by itself alone.
2) completely clearing it's orbit of rubble, i don't know... there are some planets (of the 8 remaining) in our system that don't apply to that. also, new, young solar systems will probably not apply either. are those planetary bodys to be called proto-plantes?
3) also, i think the "dominant body" restriction is not defined clearly enough. i can imagine solar systems where several huge planets have excentric orbits that at some point intersect with others... what name to use then? bloody fat comets? :)

why is this definition important? well... who knows? Computer games aren't important to me, does that mean that they should be prohibited?? probably yes :biggrin:

[mediax]

My Very Earthly Mother Just Sat Upon Neptunes Pluto.

Pluto HAS to be called a planet. What else is myveryearthlyma gonna sit upon?

Nothing, of course! ;)