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Experts meet to decide Pluto fate, Finally we'll know what a 'planet' is...
MizarKey
post Aug 14 2006, 06:06 AM
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One of many articles regarding the upcoming conference...

Experts meet to decide Pluto fate


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Eric P / MizarKey
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Guest_JamesFox_*
post Aug 16 2006, 11:07 AM
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Personally, I have to admit that I feel rather uneasy about this proposal. People are liable to reject it on unscientific grounds because it provides 'too many planets'. Also, why do they mention only three planet candidates to the news, while treating other qualifying objects in a a separate, not-mentioned to the news category? I've seen quite alot of opposition already.

I think a slightly more acceptable definition would stress the difference between the 'dwarf planets' and the 'eight classical planets', thus allowing those who are so inclined to ignore the dwarf planets, while the inclusivists would include the dwarf planets.
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Ames
post Aug 16 2006, 11:40 AM
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QUOTE (JamesFox @ Aug 16 2006, 12:07 PM) *
I think a slightly more acceptable definition would stress the difference between the 'dwarf planets' and the 'eight classical planets', thus allowing those who are so inclined to ignore the dwarf planets, while the inclusivists would include the dwarf planets.


That sounds sensible to me and something that the public could understand.
But they are going to have a field day with barycenter...
"What? Barry Sentor? - never heard of him!"

I think Pluto should be a planet(maybe dwarf maybe -oid) with a large(in comparison) moon that just happens to be large enough to set the "Barry Sentor" above Plutos' surface. Why a double planet?

We either need to make it a simple definition that the Public will understand and accept, or a rigorous (and useful) definition for scientists. Otherwise I fear that the Public may just ignore the more difficult concepts and revert to the old definition of the solar-system and the scientsts will be off in their own word of planetoids, plutinos, barrycenters...



Nick
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Ames
post Aug 16 2006, 11:44 AM
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QUOTE (Ames @ Aug 16 2006, 12:40 PM) *
That sounds sensible to me and something that the public could understand.
But they are going to have a field day with barycenter...
"What? Barry Sentor? - never heard of him!"

I think Pluto should be a planet(maybe dwarf maybe -oid) with a large(in comparison) moon that just happens to be large enough to set the "Barry Sentor" above Plutos' surface. Why a double planet?

We either need to make it a simple definition that the Public will understand and accept, or a rigorous (and useful) definition for scientists. Otherwise I fear that the Public may just ignore the more difficult concepts and revert to the old definition of the solar-system and the scientsts will be off in their own word of planetoids, plutinos, barrycenters...
Nick



Actually Barry Senter huh.gif

www.barrysenterdesign.com

Hmmm! biggrin.gif

Nick
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David
post Aug 16 2006, 11:57 AM
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Does "double planet" imply a single entity that happens to consist of two units, or two planets that happen to be revolving around each other?

In other words, can one say "Pluto-Charon is a planet"?
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MichaelT
post Aug 16 2006, 12:07 PM
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QUOTE (David @ Aug 16 2006, 11:57 AM) *
Does "double planet" imply a single entity that happens to consist of two units, or two planets that happen to be revolving around each other?

In other words, can one say "Pluto-Charon is a planet"?

I don't think so. The IAU release explicitely states 12 planets including Charon. If the double planet was counted as one entity, there'd be only 11. So they are two planets revolving around each other.

Michael
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ugordan
post Aug 16 2006, 12:25 PM
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QUOTE (MichaelT @ Aug 16 2006, 01:07 PM) *
So they are two planets revolving around each other.

Hmm... We seem to be running in circles here, so to speak. Didn't they say a body needs to orbit the Sun, not another body, in order to be classified as a planet? If so, how can Charon (and for that matter Pluto as well!) be a planet?


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Alan Stern
post Aug 16 2006, 12:57 PM
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QUOTE (ugordan @ Aug 16 2006, 12:25 PM) *
Hmm... We seem to be running in circles here, so to speak. Didn't they say a body needs to orbit the Sun, not another body, in order to be classified as a planet? If so, how can Charon (and for that matter Pluto as well!) be a planet?



Owing to its high mass relative to Pluto, Pluto-Charon's barycenter is in free space,
which means Charon is technically in orbit about the Sun, not Pluto. This is not a debatable
fact, it's just the way the dynamics works.
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ngunn
post Aug 16 2006, 01:22 PM
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QUOTE (Alan Stern @ Aug 16 2006, 01:57 PM) *
Owing to its high mass relative to Pluto, Pluto-Charon's barycenter is in free space,
which means Charon is technically in orbit about the Sun, not Pluto. This is not a debatable
fact, it's just the way the dynamics works.


The barycenter of the solar system is also in free space. Does this mean that technically Jupiter is in orbit about the Milky Way, not the Sun?
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Posts in this topic
- MizarKey   Experts meet to decide Pluto fate   Aug 14 2006, 06:06 AM
- - paxdan   IMHO pluto is NOT a planet.... Just thought i...   Aug 14 2006, 07:11 AM
- - akuo   I'm going to start a campaign to remove the pl...   Aug 14 2006, 08:20 AM
|- - David   QUOTE (akuo @ Aug 14 2006, 08:20 AM) I...   Aug 14 2006, 11:31 AM
|- - Ames   QUOTE (David @ Aug 14 2006, 12:31 PM) If ...   Aug 14 2006, 11:36 AM
- - djellison   You can think of all sorts of ways of branding whe...   Aug 14 2006, 11:45 AM
- - ups   "About 3,000 astronomers and scientists are m...   Aug 14 2006, 12:12 PM
- - rogelio   Concerning Pluto and the planet definition debate:...   Aug 14 2006, 01:06 PM
|- - JRehling   [...]   Aug 14 2006, 02:04 PM
- - remcook   JRehling, that's one of the most sensible argu...   Aug 14 2006, 02:46 PM
|- - David   I agree that the divisions are arbitrary, that the...   Aug 14 2006, 05:22 PM
- - volcanopele   David brought up a good point that this is more pr...   Aug 14 2006, 06:47 PM
|- - Alan Stern   [quote name='volcanopele' date='Aug 14...   Aug 15 2006, 11:43 AM
- - rogelio   Yes, as volcanopele and others have mentioned, ...   Aug 14 2006, 07:08 PM
- - DonPMitchell   An interesting point. Would NASA have been able t...   Aug 14 2006, 09:04 PM
- - SigurRosFan   In the news ... QUOTE Pluto the Ninth, Xena (2003 ...   Aug 15 2006, 11:18 AM
|- - DFinfrock   QUOTE (SigurRosFan @ Aug 15 2006, 11:18 A...   Aug 15 2006, 10:58 PM
|- - volcanopele   QUOTE (DFinfrock @ Aug 15 2006, 03:58 PM)...   Aug 16 2006, 12:09 AM
- - Greg Hullender   It's also worth mentioning that Ceres used to ...   Aug 15 2006, 01:47 PM
|- - David   QUOTE (Greg Hullender @ Aug 15 2006, 01:4...   Aug 15 2006, 04:56 PM
- - ljk4-1   According to SpaceToday.net via NPR (National Publ...   Aug 15 2006, 01:49 PM
|- - MahFL   I would like Pluto to remain a planet.   Aug 15 2006, 02:03 PM
- - ngunn   Does anyone feel like setting up a poll on this? (...   Aug 15 2006, 03:56 PM
- - volcanopele   QUOTE I must say that I disagree. As reductionists...   Aug 15 2006, 04:36 PM
|- - AlexBlackwell   QUOTE (volcanopele @ Aug 15 2006, 06:36 A...   Aug 15 2006, 04:45 PM
|- - volcanopele   QUOTE (AlexBlackwell @ Aug 15 2006, 09:45...   Aug 15 2006, 04:56 PM
|- - David   QUOTE (AlexBlackwell @ Aug 15 2006, 04:45...   Aug 15 2006, 05:01 PM
||- - Alan Stern   QUOTE (David @ Aug 15 2006, 05:01 PM) I d...   Aug 15 2006, 05:36 PM
||- - David   QUOTE (Alan Stern @ Aug 15 2006, 05:36 PM...   Aug 15 2006, 05:58 PM
||- - Alan Stern   QUOTE (David @ Aug 15 2006, 05:58 PM) I...   Aug 15 2006, 06:23 PM
||- - David   QUOTE (Alan Stern @ Aug 15 2006, 06:23 PM...   Aug 15 2006, 06:37 PM
|||- - Alan Stern   QUOTE (David @ Aug 15 2006, 06:37 PM) I r...   Aug 15 2006, 07:31 PM
|||- - ljk4-1   QUOTE (David @ Aug 15 2006, 02:37 PM) And...   Aug 15 2006, 08:13 PM
||- - vexgizmo   QUOTE (David @ Aug 16 2006, 10:14 AM) Ala...   Aug 16 2006, 05:58 PM
||- - David   QUOTE (vexgizmo @ Aug 16 2006, 05:58 PM) ...   Aug 16 2006, 06:04 PM
|- - JRehling   [...]   Aug 15 2006, 08:52 PM
|- - AlexBlackwell   QUOTE (JRehling @ Aug 15 2006, 10:52 AM) ...   Aug 15 2006, 09:03 PM
|- - JRehling   [...]   Aug 16 2006, 06:16 PM
|- - AlexBlackwell   QUOTE (JRehling @ Aug 16 2006, 08:16 AM) ...   Aug 16 2006, 07:25 PM
- - dvandorn   I think that the concept of "planet" has...   Aug 16 2006, 03:40 AM
- - Holder of the Two Leashes   It has been announced on the SpaceDaily website th...   Aug 16 2006, 03:45 AM
|- - mcaplinger   QUOTE (Holder of the Two Leashes @ Aug 15 200...   Aug 16 2006, 04:05 AM
|- - MichaelT   The relevant IAU press release can be found here: ...   Aug 16 2006, 09:06 AM
- - volcanopele   ? only 12? In your other post, you stated that th...   Aug 16 2006, 04:05 AM
- - dvandorn   So, is the new nursery-rhyme mnemonic for the plan...   Aug 16 2006, 04:23 AM
|- - ngunn   QUOTE (dvandorn @ Aug 16 2006, 05:23 AM) ...   Aug 16 2006, 12:44 PM
|- - Ames   QUOTE (ngunn @ Aug 16 2006, 01:44 PM) How...   Aug 16 2006, 12:53 PM
|- - ngunn   QUOTE (Ames @ Aug 16 2006, 01:53 PM) I li...   Aug 16 2006, 02:00 PM
- - nprev   Mmm...pickled spicy xylophones.... Interesting ...   Aug 16 2006, 05:11 AM
- - volcanopele   I certainly have no problem with having a lot of p...   Aug 16 2006, 05:22 AM
- - DonPMitchell   A wise choice. They have a nice physically-based ...   Aug 16 2006, 06:25 AM
- - djellison   Totally unrelated politics and political imagery r...   Aug 16 2006, 08:28 AM
- - ngunn   I wonder what happens if the mutual orbits are ecc...   Aug 16 2006, 10:31 AM
|- - ugordan   QUOTE (ngunn @ Aug 16 2006, 11:31 AM) I w...   Aug 16 2006, 10:50 AM
- - djellison   And just for good measure, an article about a back...   Aug 16 2006, 10:39 AM
|- - paxdan   QUOTE (djellison @ Aug 16 2006, 11:39 AM)...   Aug 16 2006, 11:06 AM
- - JamesFox   Personally, I have to admit that I feel rather une...   Aug 16 2006, 11:07 AM
|- - David   QUOTE (JamesFox @ Aug 16 2006, 11:07 AM) ...   Aug 16 2006, 11:15 AM
||- - JamesFox   QUOTE (David @ Aug 16 2006, 07:15 AM) 1. ...   Aug 16 2006, 11:25 AM
||- - David   QUOTE (JamesFox @ Aug 16 2006, 11:25 AM) ...   Aug 16 2006, 11:34 AM
|- - Ames   QUOTE (JamesFox @ Aug 16 2006, 12:07 PM) ...   Aug 16 2006, 11:40 AM
|- - Ames   QUOTE (Ames @ Aug 16 2006, 12:40 PM) That...   Aug 16 2006, 11:44 AM
|- - David   Does "double planet" imply a single enti...   Aug 16 2006, 11:57 AM
|- - MichaelT   QUOTE (David @ Aug 16 2006, 11:57 AM) Doe...   Aug 16 2006, 12:07 PM
|- - ugordan   QUOTE (MichaelT @ Aug 16 2006, 01:07 PM) ...   Aug 16 2006, 12:25 PM
|- - paxdan   QUOTE (ugordan @ Aug 16 2006, 01:25 PM) H...   Aug 16 2006, 12:41 PM
|- - Alan Stern   QUOTE (ugordan @ Aug 16 2006, 12:25 PM) H...   Aug 16 2006, 12:57 PM
|- - ngunn   QUOTE (Alan Stern @ Aug 16 2006, 01:57 PM...   Aug 16 2006, 01:22 PM
|- - ugordan   QUOTE (Alan Stern @ Aug 16 2006, 01:57 PM...   Aug 16 2006, 01:25 PM
|- - David   QUOTE (Alan Stern @ Aug 16 2006, 12:57 PM...   Aug 16 2006, 01:29 PM
- - ljk4-1   Just how binding is the IAU decision on astronomer...   Aug 16 2006, 12:48 PM
- - rogelio   Dateline 2015: U.S. Postal Service issues revised...   Aug 16 2006, 12:51 PM
- - maycm   My kids have a video of "Blues Clues" wh...   Aug 16 2006, 01:25 PM
- - djellison   I must admit - I was explaining all this to my eve...   Aug 16 2006, 01:37 PM
|- - David   QUOTE (djellison @ Aug 16 2006, 01:37 PM)...   Aug 16 2006, 01:49 PM
- - Tom Tamlyn   Today's New York Times has a good article on t...   Aug 16 2006, 01:44 PM
- - Greg Hullender   It does seem that it would have been useful to cre...   Aug 16 2006, 02:02 PM
- - mcaplinger   The barycenter rule is laughable, IMHO. You'd...   Aug 16 2006, 02:33 PM
|- - David   QUOTE (mcaplinger @ Aug 16 2006, 02:33 PM...   Aug 16 2006, 04:25 PM
|- - JRehling   [...]   Aug 16 2006, 04:29 PM
|- - David   QUOTE (JRehling @ Aug 16 2006, 04:29 PM) ...   Aug 16 2006, 05:14 PM
|- - AlexBlackwell   QUOTE (David @ Aug 16 2006, 07:14 AM) Ult...   Aug 16 2006, 05:31 PM
|- - JRehling   [...]   Aug 16 2006, 05:49 PM
|- - Alan Stern   [ > DPS PRESS RELEASE (Released 16 August 2006)...   Aug 16 2006, 05:51 PM
- - ljk4-1   A camel: A horse designed by committee.   Aug 16 2006, 02:42 PM
- - alan   They can't change Pluto's clasification wi...   Aug 16 2006, 03:04 PM
- - jsheff   Results are in: IAU   Aug 16 2006, 04:35 PM
|- - maycm   QUOTE (jsheff @ Aug 16 2006, 12:35 PM) Re...   Aug 16 2006, 04:40 PM
- - AlexBlackwell   I'm not sure if this has been mentioned, but h...   Aug 16 2006, 04:46 PM
- - vexgizmo   "A planet is a celestial body that (a) has su...   Aug 16 2006, 04:51 PM
- - hendric   The correct answer for the marginal cases is simpl...   Aug 16 2006, 05:29 PM
- - AlexBlackwell   The editorial that appears in the August 17, 2006,...   Aug 16 2006, 05:44 PM
- - Phil Stooke   As a rule of thumb for whether a non-spherical wor...   Aug 16 2006, 06:08 PM
|- - David   QUOTE (Phil Stooke @ Aug 16 2006, 06:08 P...   Aug 16 2006, 07:17 PM
- - AlexBlackwell   Phil Plait has an interesting take on it.   Aug 16 2006, 06:17 PM
- - volcanopele   now that I have heard the rational for the double ...   Aug 16 2006, 07:47 PM
|- - JRehling   [...]   Aug 16 2006, 07:58 PM
|- - David   QUOTE (JRehling @ Aug 16 2006, 07:58 PM) ...   Aug 16 2006, 08:08 PM
- - Jyril   The barycenter criterion may become handy in the c...   Aug 16 2006, 08:13 PM
- - jsheff   I don't have a problem with roundness as a cri...   Aug 16 2006, 08:13 PM
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