As someone on NASAWatch points out, if you take the definition literally, Jupiter (Trojans) and Earth (NEO asteroids) aren't planets, either!

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Everything I need to know I learned through Googling.

THERE ARE 8 PLANETS ONLY IN OUR SOLAR SYSTEM, FINALY!



THIS IS VICTORY OF LOGIC AND CLEAR THINKING, OUR VICTORY!

H O O R A Y !!!

Hum,
it only took me a few minutes to update the Pluto section from my website, rather than just deleting it...(reminded me a bit of defacing a statue of a pharaoh, and scratching their names from the hieroglyphs...)

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`Irony` actually does mean `metal like`...

Seriously, even Neptune gets the boot for its recently discovered trojans.

I think anyone who buys into this needs to get an astronomy program, then turn on the orbits for all known asteroids. The "belt" is something of a misnomer, they're all over the inner Solar System.

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I'm not completely heartless, the doctor who removed it told me he'd never be able to get it all.

I'm happy with the decision, pluto didn't deserve planetary status along wtih the other classical planets. Classifying it a dwarf planet or trans-neptunian object is just fine.

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Ay, amor
Dime como debo hacer
Para arrancarme este deseo
Que no me deja ni comer
Y que me da cuando te veo

Can we at least call Pluto/Charon a double dwarf planet on the grounds that their barycenter is not within either body's mass?

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[Dr. Horrible]___________________________[Penny]
Listen close to everybody's heart________And you believe there's good in everybody's heart
And hear that breaking sound_____________Keep it safe and sound
Hopes and dreams are shattering apart____With hope you can do your part
And crashing to the ground_______________To turn a life around

Yes.

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Forming opinions as we speak

"Orbital clearing" means the object dominates its neighborhood, not that there couldn't be minor bodies present. Neptune's gravity has profound effect on its surroundings. Therefore, it does qualify as a planet. Period.

If you're not happy with it, read the Footnote 1, which explicitly mentions the eight planets of the Solar system. One astronomer quipped that only it should be accepted.

The wording was selected to make it more understandable to a layman (who, after all, is the one who needed the definition, astronomers were happy without it).

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

Except for Brian Marsden, who seems to have started this whole thing.

I preferred the definition that was bandied about last week, which would have resulted in 13 (known) planets round these parts.

I appreciate that I may be in a minority in that respect.

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I offer a complete and utter retraction. The imputation was totally without basis in fact, was in no way fair comment and was motivated purely by malice. I deeply regret any distress that my comments may have caused you or your family, and I hereby undertake not to repeat any such slander at any time in the future.

Reina, have you been to Hayden planetarium, in American Museum of Natural History,
that one on the 72nd street west side Manhattan?
They have only 8 planets there for a long time, no Pluto, very smart people work there...
I'll be there in few weeks, and for sure will visit planetarium again!

Hayden Planetarium:
http://haydenplanetarium.org/

bu the way, here is scientific proof for only 8 planets in Solar system,
big work, 22 pages, but worth reading:

"What is a Planet?" (by Steven Soter, works at above mentioned place)
http://arxiv.org/ftp/astro-ph/papers/0608/0608359.pdf

First, may be know who is the "someone"?

Second, this is totally, absolutely WRONG.

IAU made very clear definition of planets, and said that
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune are planets.

Please read this work of Mr. Soter and it be very clear to you
the part of resolution which says:

RESOLUTION 5A
(1) ... (c) has cleared the neighbourhood around its orbit.

Read this work, and it be clear as a clear day what did all those smart astronomers
meant by "has cleared the neighbourhood around its orbit.":
"What is a Planet?" (Steven Soter, AMNH)
http://arxiv.org/ftp/astro-ph/papers/0608/0608359.pdf

Wow. I knew that this wouldn't change anything.

Last week, we were arguing about what to call planets, and what not to call planets.

This week we are arguing about what to call planets, and what not to call planets.

How about next week we tackle some important issues? Like war, poverty, or the icky color my office is painted.

So they rejected the proposal in the other thread?

I have to say, I was kind of growing on the idea of calling Ceres a planet. It would fit with the Titty-Boobs law more.

But, I think I'm happier with this decision to keep the great eight planets as the exclusive members.

Now, New Horizons is a mission of special importance. It is going to study one of the biggest KBOs in the solar system.

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2 good 2 need 4 engines

Ceres isn't just an asteroid any more. It's now a dwarf planet.

Let's hope that it (and other giant asteroids) get more publicity now.

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

This just in, Pluto has now changed it's name to "The object formerly known as a Planet"

In text books it name will now be replaced with a symbol

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The proceeding post was brought to you by NASA, the National Association of the Sellers of Alcohol.

Well, the upside is that it'll increase the number of amateur astronomers who can say they've observed all of the planets.

Not sure I understand the "clearing out" bit, or the bit about the Sun. I guess a previous poster has clarified what "clearing out" is defined to mean, but including only the Sun in the definition seems strange -- any chance that was a media misconception?

I can't say "New Horizons" is total waste of money since it will return new scientific information,
but that money could be very well invested into more imporatant scientific projects,
especially after we learned that bigger KBOs then Pluto exist out there.

maybe if we talked to Pluto, explained carefully to it the advantages of a more circular orbit which does not transgress Neptune's orbit. Poit out that there might be federal funding if it cooperates...

...oh wait, I just remembered: THE UNIVERSE DOESN'T GIVE A DAMN WHAT YOU CALL IT.

silly, silly topic to get worked up over. Eight, ten, thirty six... what's the difference?

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"Faith: Belief without evidence in what is told by one who speaks without knowledge, of things without parallel."

--Ambrose Bierce

http://threelittleboxes.com

Common sense has won out. Orbitally and positionally, Pluto doesn't fit in. In the Solar System family, Pluto is the pet dog, not an equal member. We haven't lost him, he just can't eat at the table anymore.