Planet question finally solved?

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aichip
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IAU has some serious problems, it would seem

Post by aichip » Tue Aug 29, 2006 3:29 am

There are some really simple logical concepts that could resolve this, but like any committee, it didn't happen with the IAU. Let's look at the logical side of this planet issue and it becomes fairly simple. In fact, why don't we work out a reasonable definition in this forum? I think we can get a far better and more acceptable definition in a few message posts.

First, I propose that anything large enough to be spherical or nearly so under its own gravitation, and orbiting a star, should be termed a planet. This is a rough concept that I think most people can agree with.

Second, if any body that would otherwise be called a planet is orbiting another body that would otherwise be called a planet AND the barycenter is outside of either body - then we have a double planet. Case in point: Pluto and Charon. Simple enough.

Third, if any body that would otherwise be called a planet is orbiting another such body, but the barycenter is within one of the two, then the body containing the barycenter is the planet and the other body is a moon of that planet. Case in point: Earth and Luna.

Fourth, any body that is not spherical or nearly so under its own gravitation, but orbits a planet, is a moon of that planet.

Fifth, any body that is not spherical or nearly so under its own gravitation, but orbits a star, is an asteroid.

We will assume that all these bodies are natural and not artifacts, so that excludes space stations, lost spacesuit gloves, communications satellites and Death Stars. :D

Now, we only have to agree on how spherical something must be and we have instantly resolved all the problems. We ignore what other stuff might be in an orbit (whee, Earth is a planet again!) and we ignore the "dwarf planet" concept. After all, how "dwarf" does it have to be? This is an artificial distinction that really plays havoc with the whole idea of defining a planet at all. Just picture "world's tallest midget" and you see how ludicrous the concept is.

In my opinion (and this is just that, my opinion) it is clear that the IAU wanted to exclude Pluto for whatever reason, and any new bodies in the Oort or Kuiper belt, and so for a personal whim they truly screwed up the definition process. The idea of having to name a whole bunch of new planets probably irritated somebody and we are just fresh out of mythological figures to work with.

A number and letter catalog code is just fine for something we will likely never see or build a McDonald's on within the next twenty years.

Comments? Disagreements?
Cheers!

Sir Charles W. Shults III

harry
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Post by harry » Tue Aug 29, 2006 6:57 am

Hello All

Pluto and many small planets are re-defined as dwarf planets.

My kids are sad that pluto is no longer a planet.
Harry : Smile and live another day.

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orin stepanek
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Post by orin stepanek » Tue Aug 29, 2006 1:44 pm

Aichip's plan is pretty much like the plan that was proposed for voting on and pretty much got rejected. I think the plan would be great if it could be implemented; but how much chance would that have? :shock:
Orin

Martin
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Post by Martin » Tue Aug 29, 2006 1:55 pm

Again -who the heck is the IAU :roll:

We can reject their decision and set precedence for future attempts. Seriously –Pass it on “R-E-J-E-C-T-E-D”!!!!

Political agendas should not enter into astronomy. It took us too long to overcome religious agendas. That is my final say in this matter---Just say NO!!!

:x

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orin stepanek
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Post by orin stepanek » Tue Aug 29, 2006 2:20 pm

Martin wrote:Again -who the heck is the IAU :roll:

We can reject their decision and set precedence for future attempts. Seriously –Pass it on “R-E-J-E-C-T-E-D”!!!!

Political agendas should not enter into astronomy. It took us too long to overcome religious agendas. That is my final say in this matter---Just say NO!!!

:x
OK! I say no.

Pete here is cite I wanted to show.
http://hubblesite.org/newscenter/newsde ... s/2006/25/
Orin

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Post by Orca » Tue Aug 29, 2006 4:06 pm

Martin wrote:Again -who the heck is the IAU :roll:

We can reject their decision and set precedence for future attempts. Seriously –Pass it on “R-E-J-E-C-T-E-D”!!!!

Political agendas should not enter into astronomy. It took us too long to overcome religious agendas. That is my final say in this matter---Just say NO!!!

:x
Political agenda?? How about clarity...as more and more TNO's are being found? The term 'planet' has little meaning indeed if any round rock counts as one!

Ultimately the 8 'major planets' have more in common with each other than Pluto and it's ilk. Most importantly, they lie within the same plane of elliptic as sun's proto-star disk.

If astronomers had discovered other TNO's back in the 30's, Pluto would never have been classified as a planet. That's my guess anyway.

I guess that deep down it really doesn't matter much, it's really all semantics. But having a more precise definition for objects such as planets can't be a bad thing.

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Post by Crowbar » Tue Aug 29, 2006 5:32 pm

This discussion reminds me of a song by one of my favorite bands. Band called "2 Skinnee J's" called Pluto. It's as if they saw this coming a few years ago, kind of....
a link to the lyrics - http://www.lyricsdir.com/2-skinnee-js-pluto-lyrics.html
Basicly the chorus of the song is "Pluto is a planet!" so all of you in the "pro-planet" camp should be downloading this song!

I'm still looking for a theme song for the "anti-planet" camp.....

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BMAONE23
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Post by BMAONE23 » Tue Aug 29, 2006 9:19 pm

orin stepanek wrote:Sorry Pete I thought it was Hubble but now I cant find it. I was going to show the picture; but I cant remember where I saw it. :oops:
Orin
Here it is Orin
http://asterisk.apod.com/vie ... +two+disks

This was actually a topic started by Harry and his first link refers to the Hubble story

Or just go directly there
http://hubblesite.org/newscenter/newsde ... s/2006/25/

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orin stepanek
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Post by orin stepanek » Tue Aug 29, 2006 11:52 pm

Hi BMAONE23! Thanks. I finally did find it and posted it on page two of this thread. I finally went into the Hubble archives and there it was. I thought that old timers was catching up to my memory banks for a while! :wink:
Orin

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Post by Pete K » Fri Sep 01, 2006 1:29 am

Orin,

I checked out that site you provided: Beta Pictoris with a second, inclined disk. Scanning the associated article indicates that the inclination of the second disk is 4 degrees. My recollection is that Pluto is inclined 17 degrees to the ecliptic. Would a secondary disk appearing at the time of the solar system's formation have this degree of inclination? What I think I'm getting at: would the dynamics allow this much "tilt?" I suppose I'm still more convinced with the idea of something perturbing Pluto from the Kuiper belt and Neptune contributing to the eccentricity and inclination of Pluto's orbit.

Pete K
Retired Engineer with a life-long interest in astronomy

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orin stepanek
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Post by orin stepanek » Fri Sep 01, 2006 4:07 am

Hi Pete. I guess it doesn't really make any difference unless the petition goes through to reconsider the voting resolving the the planets are now only eight; since a minority of scientists made the vote. I really don't see that the inclination of Pluto's orbit should make any difference though. Look at the way Neptune is tilted on it's axis. Should that have anything to do with it being called a planet? I can't see where size should make a difference unless it's too small to become spherical in shape. Mercury isn't exactly a big shot in size either. Where do you draw the line? What about the comets that get trapped in orbit around planets? They get to be called moons don't they? If Pluto and other Oort cloud members weren't formed during the same time as the planets; then where did they come from? Surly Old Sol didn't capture them from some other star. I know I'm a little prejudiced about Pluto; as I spent all my whole life with the knowledge that it was a planet. Now---who knows what will be changed next? :?
Orin

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Post by ckam » Fri Sep 01, 2006 10:26 am

Pete K wrote:associated article indicates that the inclination of the second disk is 4 degrees.
isn't it funny how surfaces of protoplanetary disks in another system intersect e.o. exactly on our line of sight? :?

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Post by craterchains » Sat Sep 02, 2006 1:59 am

, , , so NOW we all KNOW just what a "planet" is, how nice.

I just lost so much sleep over this, now I can sleep so much better that we have new names for heavenly bodies. wheeeeeee :roll:

Norval
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A poem about Pluto's fate

Post by Planetoid » Fri Oct 20, 2006 12:54 pm

This poem recently appeared in the Washington Post, and sums up pretty well the recent controversy the IAU started...

Twinkle, Twinkle, Planetoid

Twinkle, twinkle, planetoid
Out so far in inky void
Rocky core with ice encloaked
Your planethood has been revoked
The I.A.U. struck a blow
To the cosmic status quo
They're not quite sure of your fate
But it leaves us only eight
Was it that your orbit's tilted
Why you were so rudely jilted?
Could it be your little tryst
With Neptune that's got them pissed?
Despite the fact you have a moon
Your reputation they impugn.
But take some comfort in their crime--
They'll all be dead in one year's time!*
Twinkle, twinkle, far from sun
So long for now, it's been fun

*One year on Pluto is 248 Earth years

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Lol. Laugh? I nearly bought a round...

Post by Andy Wade » Sat Oct 21, 2006 10:58 am

BMAONE23 wrote:I guess this means that planetary status stops at Uranus and that big ball of gas after Uranus is just a fart. :lol:
Chortle chortle. :lol:

I must admit I missed your comment first time around.
It depends on how you pronounce 'Uranus' I suppose, but I reckon your humorous statement is far more accurate than you intended. :)

Well, it made me laugh anyway.
Regards,
Andy.

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Post by tvkrys » Sun Oct 22, 2006 6:21 pm

AND, what is the definition of "cleared the neighborhood around its orbit"... It could be argued that if you have a moon, you haven't cleared the neighborhood. So how many planets are left now?

Also, using the IAU's definition, how can we definitively say that we have discovered "planets" orbiting other stars? Haven't we just discovered that some bodies are orbiting other stars?

:D K-
God Bless America!

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Post by Martin » Tue Oct 24, 2006 7:15 pm

The truth of this is that this was all intended to just embarrass NASA for sending New Horizons to a “Kuiper belt object”. Pluto was discovered over 70 years ago and it should absolutely remain a planet. You don't undo everything just because a few drips don't like snow and ice. And that is the truth -some self serving drips with superiority complexes (I won't name names because they know who they are).

The new definition should only be allowed to effect future discoveries. Any institution that teaches 8 planets should totally be ashamed and if they are not then they should change their entire curriculum exclusively to politics and *#% kissing!!!! :idea:

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Post by Orca » Tue Oct 24, 2006 11:51 pm

Image

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Post by orin stepanek » Thu Oct 26, 2006 3:26 am

Seems like some of the newly discovered planets around other stars have eliptical orbits. These gas giants come close to their sun and go out as far as our Jupiter; yet their discoveries are calling them planets. :? I still think anything large enough to become an orb and be in orbit around a star should be called a planet. :)
Orin

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