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Pluto

Pluto

(OP)

Any comments on the demoting of Pluto as the ninth planet of our solar system ?

RE: Pluto

As long as MM's dog can keep its name...

Gunnar Englund
www.gke.org

RE: Pluto

Considering the scale of the universe, I wonder why they bothered to demote it.  Maybe they wanted to before it reached it's centennial anniversary as a discovered planet.  I wonder what the criteria is now for the various classes.

Regards,

RE: Pluto

None of the memory tricks for remembering planetary order work anymore.......

-The future's so bright I gotta wear shades!

RE: Pluto

What's next? Donald Duck?

RE: Pluto

This is all some nefarious plot.  I bet its in the DaVinci Code somewhere.

RE: Pluto

Pluto, a planet since 1930, got the boot because it didn't meet the new rules, which say a planet not only must orbit the sun and be large enough to assume a nearly round shape, but must "clear the neighborhood around its orbit." That disqualifies Pluto, whose oblong orbit overlaps Neptune's, downsizing the solar system to eight planets from the traditional nine.

RE: Pluto

There's always an option.  Pluto could simply have been "grandfathered."  end of story.

TTFN



RE: Pluto

The same announcement that downgraded Pluto upgraded 4 other objects based on the new definition so apparently we now have 12 planets.

I find it interesting that a group of several hundred of the smartest people on the planet have nothing better to do than to spend thousands (millions?) of man hours developing the first technical definition of a "planet".  If Newton et al had bothered to write down a bad definition a few centuries back then just think what these big-brains could have done with the last couple of years.

David

RE: Pluto

Reminiscent of the kind of bickering fostered by those who wish Lake Champlain was one of the Great Lakes.

RE: Pluto

Stupid question.  If Pluto was demoted because it does not clear neptune out of it's path then why was neptune not demoted for not clearing pluto out of it's path?

RE: Pluto

Horoscopes in India never dealt with Pluto. No change in my future and so no comments. However, I just started believing JAEsmile

RE: Pluto

Do they even orbit in the same plane?

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

RE: Pluto

No I don't think they do.  I believe Pluto's orbit is highly inclined compared to the other planets.

RE: Pluto

Pluto’s demotion was a long time coming.  Even my old astronomy textbook put Pluto into a class outside of the major planets and into Plutonian objects and other ‘space debris’.  There was a theory at one time that Pluto is an ejected moon of Neptune.  That theory fell out of favor with the discovery of Charon, Pluto’s moon that is nearly the size of Pluto itself.

The most popular working theory now is that Pluto used to be larger and that its moon was created by a large impact that broke the small planet into two nearly equal-sized chunks.   Another theory is that it never re-coalesced into a planet due to the gravitational influence of Neptune.

The concept of a planet is not so much a scientific one, but a cultural one.  It started out as something to describe celestial objects that did not behave as the stars.  The planets appeared to wander and engage in odd behavior like retrograde motion.  I think Pluto was kept in as a planet because so much effort was used to find it, and it’s the only planet to be discovered by an American.  Only later with additional knowledge did the  mistake become more apparent.

I think now that Pluto is out, the IAU will come up with a scientific definition of a planet instead of the culturally-based definition that has been used for so long.


"If you are going to walk on thin ice, you might as well dance!"

RE: Pluto

Come on astronomers.... a planet's only a planet when there's alien life forms! All others are just rocks that don't deserve being stared at. big smile

RE: Pluto

More seriously: how come they all (except Pluto) orbit in more or less the same plane (if that's true)?

RE: Pluto

it's pretty much true.

Here are the orbital inclinations in d m

M 7 0
V 3 24
E 0 0
M 1 51
J 1 18
S 2 30
U 0 46
N 1 47
P 17 09

The plane of the Earth's orbit is called the plane of the ecliptic, it is a fairly arbitrary datum, but at least we know where it is.

The accepted wisdom is that all the home-grown planets were all formed out of the same spinning disc of pre-stellar material. So all the gas in that cloud had the same angular momentum vector, so their spin vectors were aligned, even after they clumped.

Even odder is the phenomenon of orbital resonance, which is one of the reasons why Pluto and Neptune have never said hello.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

RE: Pluto

There are at least 70,000 "trans-Neptunians" with diameters larger than 100 km in the radial zone extending outwards from the orbit of Neptune. There is a vast population of small bodies orbiting the sun beyond Neptune. This kind of ring is called the kuiper belt. Pluto is not a planet. Pluto is more a system of moons composed by Pluto, Charon (Pluto's satellite) and 2003 UB313.These moons, with complex orbits between them, are called KBO (kuiper belt objects), asteroids or comets composed of rock ice.

luis

worm

RE: Pluto

What's "Pluto"? neutral

RE: Pluto

Pluto used to be a planet in the solar system. It is not any more. You may have observed it just outside Neptunus as you were entering our solar system.

Question: What made you select our Earth for your visit? The women?

Gunnar Englund
www.gke.org

RE: Pluto

skogs,

You started an idea for another Hollywood ET flick. Martians (or any other damn ETS) filing a case, in universal court of law, on you for your comments. Better get some proofs that there are no women elsewhere.

RE: Pluto

OK. Thanks for warning me. I think that I am relatively safe. We do not even have evidence that there are men out there.

Perhaps I should rephrase more PC: What are you after? AC or DC?

Gunnar Englund
www.gke.org

RE: Pluto

If you keep going on with those argues about men and women existence, to punish you, someone will put the seats on the bicycles.

atom

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