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Is Pluto a Planet?
Pete Bevin writes "Apparently, astronomers are taking a vote on Pluto is a planet! It turns out that it's just another ice-ball at the edge of the solar system, and that doesn't qualify it (or the 60-plus bodies like it) for planet status. "
What exactly is the definition of a planet? It's kind of a silly question if there's not a clear definition. I guess that's why they're taking a vote...
I should know, it is my home world
Why is everybody always picking on the little guy? :-)
And what proof is there that Jupiter is a planet, either? It's just a big old ball of gas!
- Slarty
There was some talk about this on a Discovery Channel show that I saw last year.
As an interesting side-note, the group 2 Skinnee J's have a song titled "Pluto is a Planet" on
their CD from last summer. It's kind of interesting to hear a rap song about a scientific debate.
Here's my vote:
How about slashdot stops posting the crap that the BBC puts out? This is just stupid.
Nitpicking like this makes life intolerable and annoying. Brutally club everyone who votes NO with various lovely side dishes. Stupid idiots...
People pointing out that "pluto is big enough to have a moon" should know that there is some question as to whether or not Charon is actually a moon or Pluto/Charon is some sort binary system.
Hang on a second.. If Pluto gets demoted that will leave Mercury as the odd one out in the solar system. Mercury is the second smallest planet, it has no real atmosphere.. At perihelion it is 46gm from the sun and at aphelion it is 70gm from the sun.. Thats the same sort of variation that pluto has in its orbit.. Just to add to the mess it doesn't have any moons to help its planet status.. I'll bet it won't be long before someone decides that Mercury should go too.. After that Mars could be in trouble!!!
This is a ridiculous thing to vote on.. 70 years of tradition says Pluto is a planet. There is no scientific definition of a planet. A planet is therefore defined as something that is called a planet by us. That includes Pluto.
John O'Sullivan Piercom Ltd.
osullivanj@piercom.ie +353-61-201934
It never was....
;-)
The vote is actually whether it should be given a number like all the other minor bodies in the solar system.
Interestingly enough the article does miss at least one important fact, it calls the belt of minor bodies beyond Neptune the Kuiper Belt. Many people think that Gerald Kuiper proposed this first, but an Irish astronomer, Kenneth Edgeworth beat him to it. Whenever I go to conferences on the subject there's an interesting pattern to what speakers will call the belt - Americans call it the kuiper Belt while Europeans refer to it as the Edgeworth-Kuiper Belt....
Anyway Pluto does not behave dynamically like a planet - none of the major planets exist in resonant orbits with each other, if they did then the long term stability of the solar system would be in question. However Pluto orbits in Neptune's 3:2 resonance, along with a number of other EKBO's (Edgeworthm-Kuiper Belt Objects). In my mind this makes it a large EKBO. Brian Marsden calls EKBO's in the 3:2 resonance 'Plutinos' which is a nice compromise, promoting these objects in status.
Pluto doesn't look like an EKBO though - it's albedo (surface reflection) is about 50%, almost 10 times more reflective than an other EKBO. EKBO's are *really* dark , 4% is a typical albedo, if you had a lump of coal it's albedo is about 20%......
EKBO's are so black they're *evil*
As for charon BTW, there is an alternative way to form pluto and other EKBO's by a large scale gravitational instability. In many cases binary systems are produced as a way of conserving angular momentum. I've made some movies of simulations - look at http://star.arm.ac.uk/~spm/animation.html
Scott Manley
spm@star.arm.ac.uk
It may be the last survivor of a lost population of ice dwarfs that inhabited the primeval solar system.
Aha! It's the lost ice dwarves! I've been looking for them, since they started stealing my underwear a few weeks ago...
Therefore it must be a planet.
Once a planet, always a planet. If they screw up, then why should the planet get demoted?
. . . to use it as coolant on our Dyson sphere.
Stefan Jones
With depravity,
I break lots of gravity
Blast past the atmosphere
to the last frontier
I go boldly through space and time
The sky's the limit,
but the limit isn't the sky
I break orbit by habit,
I ignite satellites and leave rings round the planets
A flying ace like that beagle,
nevertheless this alien remains illegal
Cause their discovery don't cover me
the immigrants been left in the cold
to grow old
and disintegrate
Discriminate
against the distant and disclaimers,
Cause small minds can't see past Uranus
When I shun their race
cause that's just a phase
and my odyssey runs in 2001 ways
And I can see clearly now like Hubbell
shoved off the shuttle,
here's my rebuttal
It's a planet.
Who do you represent?
I represent the smallest planet
A tourney in this journey
versus those who tried to ban it.
If you don't agree
go see interplanet Janet Cause
the sun is star like
Pluto
is planet.
So lend me all ears
and let me state my case,
about all the types of satellites we must embrace
Cause like parents'
great-grandparents,
this planet was an immigrant,
to deport it's an offense.
It's an upstanding member of the solar system
Abide the laws of Earth and make it a victim.
Of Proposition
107,
When Pluto spawns a moon it will apply to the heavens.
A dandy like Judas of a chariot
If you demote this boat
remote to a goat
It's like taking ET's custody from Elliot,
support yours
clearly put cause,
simply put
Pluto is a planet. Pluto!
Pluto is a planet. Pluto!
Pluto is a planet. Pluto!
Pluto is a planet. Pluto!
Do it
for the
children,
if not for yourself.
Pluto
is a
http://holly.colostate.edu/~stub/2sj/2sj.html
We don't even have any clear photographic evidence of WHAT Pluto is yet, and they are VOTING on it? That's stupid. Until Pluto Express is commissioned and we get some real flyby closeups of Pluto, it's all theory.
Personally, I think Pluto IS a planet. We know it is round and not irregular like a comet and it is big enough to have it's own satellite (Charon). But these debates are useless until we get a close up picture. The best we have is massively pixellated albedo pictures that only prove that Pluto is round, at best, and has lots of dark and light areas on it's surface. Voting on a 'definitive' answer at this point is stupid.
Pluto is not going to be "demoted." What the IAU is considering is whether or not to give it a "dual status", where it would still be considered a planet but also be assigned a minor planet designation. Pluto has been considered to be a planet ever since its discovery; that is not about to change now. The recent discovery of Pluto as the largest of the Kuiper Belt objects can't possibly change decades of public perception.
The real question here is "What is a planet?" There is no hard-and-fast, accepted definition of what constitutes a planet and what does not. Sure, you can look it up in a dictionary and get some definition for it, but as far as a scientific set of guidelines that a celestial body must meet before it can be considered a planet is concerned, there is no such definition to be found.
"Something which orbits the sun" is a fairly silly guideline; as others have pointed out, this would make asteroids, comets, and man-made space probes planets. "Something which orbits the sun and has enough mass to have been shaped into a spheroid by its own gravity" is a slightly better one. We may or may not want to include such things as a requirement for an atmosphere. (Pluto has an atmosphere right now, but as it gets further and further away from perihelion, it will freeze back onto the surface of the planet.)
In the end, an object is a planet if people think it is.
People think that Pluto is a planet, so it is, and it always will be.
At the beginning of the century. When new planets started popping up (Uranus, Mercury and lastly Pluto). Astrologers had to revise their superstition, I meen alternate science, every time.
If Pluto is no longer a planet they will have to do it again. What about all the charlatans, I meen distributers who have sold astrology software, and will have to recall it.
Why do astronomers newer think about stupid, i meen alternatively gifted people feelings.
We need to vote on this. The universe lies in the balance. :-)
----
Open mind, insert foot.
Let it stay a planet! How will people remember the planets without the Nine Pickles mnemonic?
---
mjt
-----------
-----------
100% pure freak
Pluto not a planet? Next they'll be telling us William Shatner didn't really write TekWar.
For starters, the plan is NOT to revoke Pluto's status as a planet, but it is instead a vote on whether to confer dual status (planet/Kuiper-belt object) on Pluto.
Regarding BBC's credibility, that's up for debate, but this has been discussed in sci.astro for the last few weeks -- it's a real story.
No, having a moon (or "companion") does not guarantee planet designation, at least one asteroid has been found to have a companion, and probably many more will.
let's hear it for astronomy stories on slashdot! go rob!
Posted by AbsoluteTruth:
That was a well stated group of reasons for Pluto's planetary status. Previous comments addressed Pluto's moon Charon's size. It was inferred that it was not large
enough. That is absurd. Charon is the largest natural satellite in our solar system relative to the size of its planet. Only Earth's moon is even close to this comparative size.
It is a known fact that they have been considered a double planet for some time. The object that orbits the Sun is actually the center of gravity between the two. Charon
is definitely a moon. Pluto has an atmosphere. And, it orbits our Sun on a very regular cycle that is closer to circular than any comet I have ever heard of. It is a planet
and for all that we know at this point, it could have some form of life. Luckily, they are NOT debating the possibility of it being demoted.
All I know is that no one named Larry Greenberg should be allowed anywhere NEAR Pluto, regardless if it is a planet or just a lost moon of Uranus smacked out of orbit a billion years ago by some out of control alien spaceship.
Hmm, bandersnach burgers!
Boobies never hurt anyone. - Sherry Glaser.
What good is slasdot if we don't do anything about this. We can't let the man pick on the little guy. So, let's form a petition, or a poll. Let the /. effect save Pluto!!! (What came first, pluto the planet or the dog?)
Do not meddle in the affairs of sysadmins, for they are subtle, and quick to anger.
I'm all for declassifying Pluto as a planet. I don't feel it fits the bill.
Homes on asteroids are just SO passé...
"News for Nerds" doesn't necessarily mean "News for Linux Geeks". Some of us have other nerdy hobbies. Declassifying Pluto as a planet is quite a big change in the classical definition of our solar system, just like the naming of some of those "Unnamed" elements a few years ago affected the Chemistry crowd.
If you don't want to read this sort of thing, don't read it, and for God's sake, DON'T COMMENT ON IT.
(I forget the exact value, but it was picked specifically to allow Pluto, but none of the major asteroids, to qualify.)
The problems are caused by:
It's orbit, which is closer to that of a comet than a planet
It's size, which is considerably smaller than any of the other planets
It's (believed) composition, which would qualify it as a captured comet
To add to the fun, though, Pluto has what is regarded as a moon. This fits with the definition of a planet, but comets and asteroids usually don't have moons.
(You can't count any old lump of rock as a moon, otherwise Saturn has several quadrillion moons, which make up the rings, and any speck of dust that happens to fall into a stable orbit around the Earth would need to be counted.)
If the lump of rock orbiting Pluto qualifies as a moon, it MUST follow that Pluto qualifies as a planet, not an asteroid or comet. Likewise, if Pluto is relegated to either an asteroid or comet, it's moon must likewise be downgraded, and the definition of a moon altered if necessary to exclude it.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
But, why is it that I am more concerned that it's referanced to a BBC artical? Uh, teen age encription experts discover it's not a planet or what? BBC credibility seems more like tabloid that news level lately.... Or is it just me?
Seriously though, here's the list of why Pluto is considered a planet:
- Discovered in a search for a ninth planet, based on apparent perturbations in Neptune's orbit (which have since been explained otherwise)
- Discovered when we didn't really know about the Kuiper belt.
That's about all. Why Pluto isn't a planet:- Looks like a Kuiper belt object, smells like a Kuiper belt object, walks like a Kuiper belt object.....Pluto has similar composition, size, and orbital characteristics as the Kuiper belt objects (yes, similar size. It's a particularly big one, but it's not horribly out of the class)
- Orbit is highly inclined from the equatorial plane, in addition to being quite highly elliptical (the whole "closer-than-Neptune" thing)
- Pluto and Charon are quite close to being the same size; they really function more as a double-body system. I believe the barycentre (centre of their mutual orbits) of the system is above the surface of Pluto; correct me if I'm wrong.
Oh, and we have very good data about Pluto. Just because we haven't sent a probe doesn't mean we don't know anything. HST data is especially good, but you can learn a lot just from looking at little point sources. Resolving the surface doesn't really give you any more information.--
On the bright side, Pluto would no longer be the runt of the planetary litter but the king of its own domain as the largest, and first-discovered of the Kupier-belt objects (EKBO).
This has happened before. Ceres was discovered in 1801 and was called a planet for a while. It even got an element named after it, like Pluto. But eventually, when they found a bunch of other small bodies in similar orbits it became the biggest asteroid instead of the smallest planet.
I'd say Mercury is safe in it's planethood unless they find a horde of little Mercuroids orbiting near the Sun that have somehow escaped our notice until now. Unlikely.
...they class it as a non-planet due to the fact that it looks like an ice ball, only to have the Pluto Express take a detailed survey and say that it's a rock with an icy skin and have to RE-classify it as a planet. D-OH!
-- Wiccan Army, 13th Airborne Division "We will not fly silently into the night"
Loren Osborn
Loren Osborn
I've seen him on Disney cartoons. He's got four legs and he barks, there's no way he's a planet.
-Eric
Do we get to vote if there's a God, or if cold fusion is possible or if there is an aether or if tachyons exist or how about anti-gravity? Can we vote on that too?
Come on now, for centuries science has challenged popular beliefs in ordre to prove conventional wisdom wrong; now we're going to make science dependant on popular beliefs and who has the fastest internet connection? Blech.
The only sure thing here is that Pluto is most definately not Greek...
--
Aaron Gaudio
"The fool finds ignorance all around him.
"Every man is a mob, a chain gang of idiots." - Jonathan Nolan, Memento Mori
What happens when Pluto and Neptune exchange places in orbit, as they do every so often?
"My very energetic mother just sent us practically nothing" ?
--
Aaron Gaudio
"The fool finds ignorance all around him.
"Every man is a mob, a chain gang of idiots." - Jonathan Nolan, Memento Mori
I wonder what the working definition of "planet" would be, if this passes. Is there a size requirement? Orbital eccentricity limit?
Maybe its just a case of the big planets trying to close out the game, now that they've won.
"Genius may have its limitations, but stupidity is not thus handicapped." --Elbert Hubbard (1856-1915)
Poor wee Pluto.
I'm out of my tree just now but please feel free to leave a banana.
A couple of years ago I worked on a project when JPL had a call for proposals for sending a probe out there. Really interesting stuff and a lot of design challenges.
One of the mission drivers was to get the probe out there before 2018 or so. At that point Pluto is going to swing out far enough that it's atmosphere of ammonia (or some other nasty gas) is going to collapse back into a solid. Right now we're relatively lucky in that Pluto is at it's closest point in it's orbit - a measly 30 AU's or so. Basically at the end of the report we wrote up we said that a probe has to launch by 2005 or it gets REALLY hard to get it out there in time.
Anyway, two facts compell me to think it has to be a planet (note: either of these by themselves is not enough since they occur in other places in the solar system) 1) it has an atmosphere, 2) it has a moon (or are there two now?) None of the other objects out there or in the Kuiper Belt are known to exhibit those qualities.
----- obSig
So these dweebs are taking a VOTE on a planet???? Geez, don't they have more pressing problems to address? I say we send one of these brainiacs out there and find out fo himself. Then he can radio back whether or not it really IS a planet. Then we self-destruct his ship.
So Jupiter is a giant ball of gas as well. I vote we eliminate THAT as a planet, too!!!
upon humanity if we continue upon this quest to disrespect ...
:-)
> new planets started popping up (Uranus, Mercury and lastly Pluto).
;-)
Ooops..... you Mean Uranus, Neptune and Pluto
Mercury is one of the classical 5 planets (other than earth)
...all of my copies of that old Doctor Who story called _The Tenth Planet_? What do they expect me to do - cross that out and label it _The Ninth Planet_??? Just doesn't have the same ring to it...
;)
Oh, and if anybody happens to have a decent copy of the fourth episode of _The Tenth^h^h^h^h^h Ninth Planet_, I'd be glad to come over and help you relabel it
70% of Earth's mass is water, so it is mostly not either a gas giant or Mars-style solid rock planet.
Gas Giants do not count random rocks as planets anyway.
I think, therefore thoughts exist. Ego is just an impression.
Here's a working definition that I will use: "An object with a definite geological history (even if it has terminated in the meantime)in a static gravitation orbit of a larger object in which the center of mass is closer to the larger object than to the planet itself".
In this definition moons will not work out unless they have sub-moons. The sun will not be a planet unless you compare it to the rest of the galaxy (perhaps add a kludge stating "can have no continuous thermonuclear reactions over a large volume"). So a planet is a relative definition here.
Mercury, Venus, Earth, and Mars have a definite period of geological history so they are all planets.
At first it would appear that Jupiter is not a planet because it doesn't have exterior rocks, but ask any geophysicist if solids are all that there are to geology. The answer then is that Jupiter, Uranus, and Neptune are then planets.
It is now clear than Pluto is not a planet because it does not have any definite geological history. Sure it has geology but it has no history past the point in which it coalesced into a dirty snowball. It does satisfy the other half of my definition but a history must be found for the first part.
Suddenly, the hairy finger of a familiar monkey tapped me on the shoulder. It was time.--G. T.
I heard the BBC World Service broadcast about this last night - unless better info comes out soon, the whole thing looks like a giant ego trip for the people trying to dismiss Pluto.
One astronomer made the good point that although Pluto is erratic, it still meets the planetary criteria. "Just because a duck is small, you don't call it a chicken". The astronomer against Pluto didn't even bother to give any coherent argument, just kept saying that Pluto was a "weeny little thing" and that it was nowhere near being one of the "proper planets". I mean, what kind of garbage is this?
And since when has a poll been the correct method for determining scientific "truth"? We don't have people voting on whether we should keep Einstein's theories, or whether gravity exists. I think the whole concept behind this is ridiculous. I agree that Pluto has some irregularities, but it doesn't seem to meet the criteria for other astronomical objects - and there's no just cause to throw out the entire scientific process.
Anyway, my $.02.
Leilah
~ Leilah
Yo,
If you work out the math, you'll see that the force of the sun on the "moon" is always "winning" against the force of Earth on the "moon"--the orbit of the "moon" is always bent toward the sun (unlike, say, the moons of Jupiter, whose orbits are always concave toward Jupiter). So what we think of as Earth's moon is more logically considered a companion planet to the earth. It's quite a bit smaller, and its orbit is significantly perturbed by Earth, but you really can't make a case for saying it orbits Earth.
At least, that's what I remember learning in some class somewhere.
mikey
Liberty uber alles.
BBC is an imperialist tool of a faded empire. surrender small island nation! Ireland has a stronger economy.
Certified Black Helicopter Pilot *** Unwitting Dupe of One World Gov'ment
actually, Charon's nearly the same size as Pluto, if I'm not mistaken, causing the two to almost revolve around each other.
Electric Eye,
... if we call Pluto one, there's a lot more things that deserve the name, which is probably a bigger mistake than the original one made in 1930 by labeling it Planet IX.
would you specify exactly what the "more pressing problems" are that the International Astronomical Union should be addressing?
Immigrant rights for Martians? Mining regulations for Ganymede? Food for hungry Titanites?
The IAU are the people who regulate the definition of planet
lake effect weblog
{Network engineer in Chicago--looking for work!}
This was written to a filksinger who wrote a song about the controversy (which is NOT new):
Thank you very much for "immortalizing" me in your humorous but thoughtful song "Planet X". I am very flattered! I was aware of your poem but did not know that you had made a song of it and recorded it in your album "Shining My Flashlight on the Moon".
Yes, your song reflects my opinion with regard to the planet Pluto. I still think that it would be a grave mistake to degrade Pluto to a minor planet. Although Pluto is small compared with the other major planets, it is still more than twice as big as the largest known minor planet, Ceres. Furthermore, it is not only Pluto's size that counts, but the entire fascinating story associated with that planet which has been known as such for 67years. Now that Pluto's discoverer, Clyde Tombaugh, is dead, Pluto's status has become even more a closed chapter in the annals of astronomy. WGPSN has started to think about how to commemorate him, preferably by naming some large feature on Pluto or on its moon, Charon, after him.
Kaare Aksnes
President -- IAU Working Group for Planetary System Nomenclature
lake effect weblog
{Network engineer in Chicago--looking for work!}
I can never remember mnemonics...
-- Meet the Residents -- http://www.residents.com/
This seems like one of those meaningless philosophical questions, like whether IE is part of Windows.
Hummm... thats a bonus =)
IMHO, its if doesn't classify as a planet then the damn thing is just a wannabe. Just like NT.
The fact that it will annoying the astrologers are just a big old bonus if ya ask me.
Lets ditch pluto! =)
"Computers will never truly be free until the last windows user is strangled with the entrails of the last mac user."