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Pluto May Soon Not Be A "Planet" ????

2nyRiggz said:
Do we address it as Pluto/Charon now or single them out
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Well, this was supposed to be released after the summit, but I suppose it's okay to talk about it now. You see, now that they've found another planet out there beyond Pluto, they've decided that in order to keep in simple for the kids out there, we'll be renaming them "Huey, Dewey, and Louie".
 
Crap, now I can't use the sentence to remember the order of the planets in our solar system anymore. ;)

And as the P from Pluto was used for the word planets, it will be hard to find another one, especially as the N from Neptune stood for nine...
 
So what's the definition? That article you linked to doesn't really explain why pluto no longer counts.

aha...

Much-maligned Pluto doesn't make the grade under the new rules for a planet: "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit."

Pluto is automatically disqualified because its oblong orbit overlaps with Neptune's.
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http://www.iht.com/articles/ap/2006/08/24/europe/EU_SCI_Planet_Conundrum.php
 
Veldek said:
Crap, now I can't use the sentence to remember the order of the planets in our solar system anymore. ;)

And as the P from Pluto was used for the word planets, it will be hard to find another one, especially as the N from Neptune stood for nine...
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You could go depressing:
More violence every month just surrounds us now.

Or not:
My very energetic movements just startled Uncle Ned.

:p
 
I'd like an avatar with the Disney Pluto, with the red "No" slash across his face. Maybe in a small font, "Not a planet" across the bottom. Anyone seen this?

;)
 
clayj said:
There were 9... then it was going to be 12 (!)... then someone did a sanity check and decided that 8 was smarter.
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Why would it be smarter?

We have millions of objects orbiting our sun, therefore are within our solar system.

If the object is of a much greater size than the norm, I'd say it should be considered a planet, regardless of its distance from the center.

While in the end, what the thing is being called matters very little, I think objects of Pluto's size stand out quite a bit compared to the typical debris whirling around.
 
i just hope they don't make any major changes before i get completely done with school.
 
Josh said:
Why would it be smarter?
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There were basically two things the IAU (I think that's who made this decision) could do:

1. Freeze the definition of what is a "planet" as being the Classic Nine.
2. Redefine what is a "planet". Based on the parameters they decided on, this would either reduce the number of planets to 8, or expand it (for now) to 12, with the possibility of more planet-sized trans-Neptunian objects being discovered in the future.

The problem with #1 is that it fails scientific rigor. How can one spatial object (Pluto) be a planet, while others (Xena, Charon, Ceres, Ganymede, Titan, etc.) are NOT, even though they are also large (some larger than Pluto, even). Just because Pluto was discovered much earlier? I'm pretty sure Ceres was detected even before Pluto was, and of course the Jovian moons were discovered by Galileo.

So, a redefinition was in order. Demoting Pluto into a new category which no one, outside of astronomers, will care about (and thereby setting the number of planets at a more-or-less-permanent 8) makes more sense to me than expanding the criteria for what's a planet so that the number jumps to 12, or 37, or 42.

Unless some BIG planet is discovered out in the Kuiper Belt or the Oort Cloud, the number of planets will remain 8 for good.
 
I think the reason that 8 is more appealing than 12+ is that in the end we like to feel special. If there are many many planets in the solar system it detracts from our planet's significance. That, to me, is the key logic behind coming up with a restrictive rather than expansive definition.
 
miloblithe said:
If there are many many planets in the solar system it detracts from our planet's significance. That, to me, is the key logic behind coming up with a restrictive rather than expansive definition.
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Of course, we're special and significant in so far as we're the only planet in the Solar System that supports life.

If and when we find out that isn't the case we'll just have to come up with something else to make ourselves feel important. ;)
 
I honestly think that Pluto should stay a planet, not because of any of the technoligical mumbo jumbo, but just because of the simple fact that billions of people have recognized it as a planet for their entire life :) Plus, I don't really care about weather it's a planet or not, just because it is so unimportant to me. But I do think that it's not nessessary to remove it from our list of planets...
 
miloblithe said:
So what's the definition? That article you linked to doesn't really explain why pluto no longer counts.

aha...



http://www.iht.com/articles/ap/2006/08/24/europe/EU_SCI_Planet_Conundrum.php
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Seems to me that would also disqualify Neptune as it has not "cleared the neighborhood around its orbit". Seems like both planets have not done so... I know I am missing the entire agreed upon definition that would probably clear that up, but the article is stil very unclear.
 
Good point that "cleared it's neighborhood" is a little ambiguous. Technically, wouldn't it disqualify anything with a moon?
 
emw said:
Good point that "cleared it's neighborhood" is a little ambiguous. Technically, wouldn't it disqualify anything with a moon?
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No, because moons orbit planets.

I think the "cleared its neighborhood" means that the area of its orbital path is not filled with randomly-orbiting, persistent objects... any large planetary body is either going to force objects to orbit it directly (e.g., the Moon, Europa, Io, etc.) or in resonance with it (e.g., Jupiter's Trojan asteroids, which are found at the Jupiter-Sol L4 and L5 points along Jupiter's orbit, or the asteroid Cruithne, which orbits in a complicated resonance with Earth), or it'll suck in the object (e.g., any asteroid running into a planet) or eject it out of its orbital space.

The stuff out in the Kuiper Belt and Oort Cloud more or less orbits randomly, in non-planetary orbits (so the "neighborhood" is filled with random stuff and is not clear), and the stuff in the asteroid belt is pretty much the same. Random interlopers like near-Earth asteroids don't count because they're just passing through.
 
Zwhaler said:
I honestly think that Pluto should stay a planet, not because of any of the technoligical mumbo jumbo, but just because of the simple fact that billions of people have recognized it as a planet for their entire life :)
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But that was true for Ceres in the 1800s, which was booted from the list after people realized that it was merely the largest of a countless group of objects in the asteroid belt.

People can adapt.
 
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