Pluto - Not a Planet?

[ronthepon]

Hey, relax!

 

We merely were not aware of that hard definition for a planet.

 

Or... maybe I just speak for myself... because I had not seen the article at all.

[Turtle]

Hey, relax!

 

We merely were not aware of that hard definition for a planet.

 

Or... maybe I just speak for myself... because I had not seen the article at all.

No worries mate; I have been operating under the principle of reading what I reply to is all.:lol: :shrug: :)

[Boerseun]

Sorry Turtle - the page crashes whenever I try to open it, so I haven't actually read the whole thing. But what I can understand from the whole issue is that in order to clarify Pluto's status, they must redefine what are planets, and what are not. They can't simply say "okay - beyond Neptune, there's a new classification system", can they? They have to be consistent, no?

 

Clearly, we can't say that a moon is a moon because it revolves around a planet. That won't do. In a planet/moon system, they both revolve around their common center of mass, and the planet will then simply be the bigger of the two 'moons' revolving around the same point. There are no fundamental difference between the Earth and the Moon, except for the little bit of activity on the surface of the Earth. Take that away, and the Earth will simply be a bigger version of the moon, orbiting the same point. The fact that the point around which they orbit is below Earth's surface, is moot - as long as it's not the exact center of Earth, both Earth and the moon will orbit around it.

So, are planets simply the biggest moons in any given planetary system? And are 'stars' simply the biggest planets in any solar system? Forget about the sun's nuclear fire - as far as composition is concerned, there's not a lot of difference between the sun and Jupiter. Yet, Jupiter is a planet, same as the Earth...

[Turtle]

I thought Pluto was a dog?! What's going on here!

Oh and I read this too Sir T! Trying to trip up ol' Turtle.:lol: Pluto the Dog Mr. Disney named after Pluto the planet Pluto discovered & named in 1930 by Mr. Tombaugh & which is still going to be called Pluto but which is proposed to no longer be a planet but a pluton. :shrug:

[Turtle]

. They can't simply say "okay - beyond Neptune, there's a new classification system", can they? They have to be consistent, no?

Yes, they (IAU) can simply say that; moreover they must & must consistently. The discovery of the new objects demands a redefinition. Science is always ammendable; this is an ammendment.

 

Clearly, we can't say that a moon is a moon because it revolves around a planet. That won't do...

Yes we can & do say that. The planets (and now plutons) orbit a sun (star) . Moons orbit planets. It is completely unambiguous & logical. I fail to see the confusion.:lol: :shrug:

[cwes99_03]

Sorry Turtle - the page crashes whenever I try to open it, so I haven't actually read the whole thing. But what I can understand from the whole issue is that in order to clarify Pluto's status, they must redefine what are planets, and what are not. They can't simply say "okay - beyond Neptune, there's a new classification system", can they? They have to be consistent, no?

 

Clearly, we can't say that a moon is a moon because it revolves around a planet. That won't do. In a planet/moon system, they both revolve around their common center of mass, and the planet will then simply be the bigger of the two 'moons' revolving around the same point. There are no fundamental difference between the Earth and the Moon, except for the little bit of activity on the surface of the Earth. Take that away, and the Earth will simply be a bigger version of the moon, orbiting the same point. The fact that the point around which they orbit is below Earth's surface, is moot - as long as it's not the exact center of Earth, both Earth and the moon will orbit around it.

So, are planets simply the biggest moons in any given planetary system? And are 'stars' simply the biggest planets in any solar system? Forget about the sun's nuclear fire - as far as composition is concerned, there's not a lot of difference between the sun and Jupiter. Yet, Jupiter is a planet, same as the Earth...

 

Boer, Turtle is right. They are the governing body on what gets called what astronomically and they can just change the definition if they all agree to do so.

 

A moon is a planet-like body that revolves around another object orbitting a star. Thus if Charon actually revolves around Pluto, it would still be considered a moon not a planet.

 

Let's get one more thing straight. A Pluton is still a planet. They are proposing keeping Pluto as a planet and adding 3 more Xena, Charon, and Ceres (which is not farther out than Pluto but between Mars and Jupiter).

 

The reason for including Charon in the list is that they are going to officially say that Pluto and Charon are a binary planet system. This would mean that they each turn around a center of mass that would not be within the sphere of either planet (this is my interpretation). However, from my reading on other source sites, this is not the case, though the information is limited because we have not had a satellite to interact with them yet and our pictures from Hubble and other telescopes are grainy at best.

 

http://www.chron.com/disp/story.mpl/nation/4119998.html

http://www.clickondetroit.com/seenon4/9684562/detail.html

[Racoon]

This just in from Prauge: the Pluton!? :shrug:

 

http://news.scotsman.com/scitech.cfm?id=1194292006

 

And this in this morning...

I'm not really thrilled with it, but thats what the big Boys and Girls decided :lol:

 

http://www.msnbc.msn.com/id/14364833/

 

The tally of planets in our solar system would jump instantly to a dozen under a highly controversial new definition proposed by the International Astronomical Union.

 

Eventually, there would be hundreds of planets, as more round objects are found beyond Neptune.

 

The proposal, which sources tell Space.com is gaining broad support, tries to plug a big gap in astronomy textbooks, which have never had a formal definition for the word "planet." It addresses discoveries of Pluto-sized worlds that have in recent years pitched astronomers into heated debates over terminology.

 

The asteroid Ceres, which is round, would be recast as a dwarf planet in the new scheme.

Pluto would remain a planet, and its moon Charon would be reclassified as a planet. Both would be called "plutons," however, to distinguish them from the eight "classical" planets.

A far-out Pluto-sized object known as 2003 UB313, currently nicknamed Xena, would also be called a pluton.

That would make Caltech researcher Mike Brown, who found 2003 UB313, formally the discoverer of the 12th planet. But he thinks it's a lousy idea.

 

"It's flattering to be considered discoverer of the 12th planet," Brown said in a telephone interview. He applauded the committee's efforts but said the overall proposal is "a complete mess." By his count, the definition means there are already 53 known planets in our solar system, with countless more to be discovered.

 

More on the link...

[cwes99_03]

I don't necessarily like it either as a amateur cosmologist. I don't think they can prove Ceres or other distant objects formed into a sphere due to grvitational pull. These could have been formed due to collision.

[Turtle]

I don't necessarily like it either as a amateur cosmologist. I don't think they can prove Ceres or other distant objects formed into a sphere due to grvitational pull. These could have been formed due to collision.

Actually there is a threshold that is calculable. I haven't run across a reference yet, but it's out there.

There is no question a lot of people aren't "happy" about all this renaming, but nonetheless it is necessary to accomodate new discoveries. Not all that different from digging up new hominid fossils.:cup:

Science is always ammendable.:hihi:

[cwes99_03]

I quite agree, but I don't think that the group is doing a good job (according to the news reports I've read). They seem to be making a couple of quick decisions, and most likely IMHO will be back at the table in the next 10 years doing this all over again.

[Turtle]

I quite agree, but I don't think that the group is doing a good job (according to the news reports I've read). They seem to be making a couple of quick decisions, and most likely IMHO will be back at the table in the next 10 years doing this all over again.

 

Again I have to reference the scottsman article I posted:

The IAU has taken two years working out the differences between planets and smaller Solar System bodies such as comets and asteroids.

http://news.scotsman.com/scitech.cfm?id=1194292006

What quick decisions?:cup: Everyone who actually read the article - the entire article - raise your hand.:hihi:

[cwes99_03]

I've never read the newsscottsman. I've read a dozen other articles. They have actually been looking at this issue since the 1970s. But the major sit down and make a decision only started <2 days ago. Thus the quick decision. I expected a much better definition than what has been posted on the numerous other articles about this conference they have going on.

 

Among those are the ones I pointed to earlier plus a couple others I've thought up recently.

 

Elliptical eccentricity, mass, volume, spherical shape, tilt, composition, distance ratio (this is from one of those articles above, seems that there's a pretty loose but steady ratio relationship between the accepted planets and their distances from the sun that I've never verified yet), and how about revolution and rotation periods.

 

Maybe the articles I've been reading are simply too vague.

 

Funny thought though in an article I just read.

What happens to all the astrological thought from the past hundreds of years? I've heard it said before (maybe even on this forum) that if the planets weren't known about then they can't affect your sign. It is too laugh. :hihi:

[Turtle]

I expected a much better definition than what has been posted on the numerous other articles about this conference they have going on.

 

Maybe the articles I've been reading are simply too vague.

 

Funny thought though in an article I just read.

What happens to all the astrological thought from the past hundreds of years? I've heard it said before (maybe even on this forum) that if the planets weren't known about then they can't affect your sign. It is too laugh. :)

The topic is highly controversial, which I fail to understand.

Here is the absolute Latest News:

http://www.space.com/scienceastronomy/060816_planet_definition.html

Hard to fit in any astrological guffaws what with all the numerological chortling I have going.:cup: :hihi: ;)

[cwes99_03]

OK, that confirms my thoughts on the center of rotation of charon and pluto, or at least the ideas behind why we could consider charon a planet (because it and pluto revolve around a bericenter that is outside of the sphere of each mass).

I have to say though that all that I've read (though limited) doesn't suggest that they actually exist in this configuration.

[TheBigDog]

If I am standing on some object in space, and I am at rest on the surface of that object, and I tee up a golf ball and crank a sweet shot with a driver, and the ball reaches the escape velocity of that object.... then I am not standing on a planet.

 

Bill

[TheFaithfulStone]

If I am standing on some object in space, and I am at rest on the surface of that object, and I tee up a golf ball and crank a sweet shot with a driver, and the ball reaches the escape velocity of that object.... then I am not standing on a planet.

 

I hereby dub this "The Golf Ball Planet Postulate" :hyper:

 

TFS

[Jay-qu]

I hereby dub this "The Golf Ball Planet Postulate" :cup:

 

TFS

Its good enough for me!

 

:(