Pluto is no longer a planet

Medicine, Science & Technology Forum

PRAGUE, Czech Republic (AP) -- Leading astronomers declared Thursday that Pluto is no longer a planet under historic new guidelines that downsize the solar system from nine planets to eight.

After a tumultuous week of clashing over the essence of the cosmos, the International Astronomical Union stripped Pluto of the planetary status it has held since its discovery in 1930. The new definition of what is -- and isn't -- a planet fills a centuries-old black hole for scientists who have labored since Copernicus without one.

Although astronomers applauded after the vote, Jocelyn Bell Burnell -- a specialist in neutron stars from Northern Ireland who oversaw the proceedings -- urged those who might be "quite disappointed" to look on the bright side.

"It could be argued that we are creating an umbrella called 'planet' under which the dwarf planets exist," she said, drawing laughter by waving a stuffed Pluto of Walt Disney fame beneath a real umbrella.

The decision by the prestigious international group spells out the basic tests that celestial objects will have to meet before they can be considered for admission to the elite cosmic club.

For now, membership will be restricted to the eight "classical" planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

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.

Instead, it will be reclassified in a new category of "dwarf planets," similar to what long have been termed "minor planets." The definition also lays out a third class of lesser objects that orbit the sun -- "small solar system bodies," a term that will apply to numerous asteroids, comets and other natural satellites.

It was unclear how Pluto's demotion might affect the mission of NASA's New Horizons spacecraft, which earlier this year began a 91/2-year journey to the oddball object to unearth more of its secrets.

The decision at a conference of 2,500 astronomers from 75 countries was a dramatic shift from just a week ago, when the group's leaders floated a proposal that would have reaffirmed Pluto's planetary status and made planets of its largest moon and two other objects. (Watch why some think planet size doesn't matter -- 3:39)

That plan proved highly unpopular, splitting astronomers into factions and triggering days of sometimes combative debate that led to Pluto's undoing.

Now, two of the objects that at one point were cruising toward possible full-fledged planethood will join Pluto as dwarfs: the asteroid Ceres, which was a planet in the 1800s before it got demoted, and 2003 UB313, an icy object slightly larger than Pluto whose discoverer, Michael Brown of the California Institute of Technology, has nicknamed "Xena."

Charon, the largest of Pluto's three moons, is no longer under consideration for any special designation.

Brown was pleased by the decision. He had argued that Pluto and similar bodies didn't deserve planet status, saying that would "take the magic out of the solar system."

"UB313 is the largest dwarf planet. That's kind of cool," he said.

Dammit! I was looking forward to new planets. Stupid 8 planet solar system.

I blame Dubya.

Pluto hater.

-HECK!

Are darn, and ive just finish memoriesing that poem to remember the order of the planets ... im going to have to think of another one now ... Stupid Pluto, had to get itself demoted

you can still remember the poem, just forget the last part.

My Very Excellent Mother Just Sent Us Nine (Pizzas)" and "My Very Easy Method Just Simplifies Us Naming (Planets)" it will make no sence without the P

Extra credit if you can name our sun and Earth's moon.

-HECK!

Man, did they HAVE to drop Pluto? Couldn't it have been Uranus instead?



Why do they need to mess with our solar system?


I'm with Heck... it's all Dubby's fault.

Yeah they keep Uranus but drop Pluto. Now the Uranus jokes will never end.

I too blame Dubya. I think Pluto was too far out for him.

I think that MOST THINGS are too far out for him, and his comprehension!

Uranus is cool. Bum rap on its name. Stupid kids.

I say we believe the Sun revolves around the Earth and be done with it.

-HECK!

I say that we just create a crap load of new planets, and name 'em after cartoon, and comic, characters!

I was really looking forward to twelve planets! And I like Pluto Stupid Dubya

The final definition for a planet, taken from wikipedia:

The final definition, as passed on 24 August 2006 is

A "planet" (1) is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

A "dwarf planet" (2) is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

All other objects (3) orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".

Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of Trans-Neptunian objects.

Footnotes state that:

1. The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
2. An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
3. These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

well, i actually think that, of the proposals made, the one that passed actually makes the most sense. the first proposal (the one that added planets), when one thinks about it, actually had several major flaws, the most notable being the fact that, given its definition, it left room for over 200 potential "planets" to be added.

still though, i have to agree with this man: "The analogy that I always like to use is the word "continent". You know, the word "continent" has no scientific definition ... they're just cultural definitions, and I think the geologists are wise to leave that one alone and not try to redefine things so that the word "continent" has a big, strict definition." (Mike Brown)

Clinton started this planet destruction process. Clinton fired the Nuclear powered rocket with Nuclear tips that destroyed Pluto.

Check your facts! You people live in a dream world!

Yes, unlike Dubya, Clinton could say "nuclear", but the man used them to destroy the weakest most non threatening planet in our solar system.

And now his wife wants the job.

This is the work of Al Qaeda. Will their villany ever be stopped.

-HECK!

Osama hated Pluto. Well known FACT. He was raised to hate Pluto.

Astronomer with disperate need-of-notoriety (let's call him Joe): "Hey, I've just found a new planet".
Astronomer with disperate need-of-funds (let's call him Jim): "Man, how can you call this stinky ball of rock a planet? Then my recently discovered UB-571a,23/cTNB44d (aka Bob) is also a planet."
Joe: "No, it doesn't, it orbits too far from the Sun."
Jim: "And your 'planet' is smaller than mine."
Joe: "But my planet has a satellite."
Jim: "No, it is not a satellite, because the center of gravity is outside the bodies."
Joe: "Aha! Then I just found two planets!"
Jim: "Uhm. Let's talk it with a couple hundreds burocrats from Europe and see what they say."
Joe: "Ok."
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Turning serious:
Let's them say what they want, Pluto is a planet for me. Do they needed to re-define moons? In fact, moons are of two categories: the ones which formed together with the planet (such as Earth's moon, or Ganymede, Io, Europa, etc. for Jupiter), and the ones which were captured by planet's gravity (The two Mars' moons, for instance). However, no need for a change in definition for moons has been felt by the IAU.
When I go to Wikipedia and see all the pages about Pluto being renamed and corrected, I think this statement of the IAU is non-sense.

This revisionist mentality is frakin' lame. These egghead doofus' should try and, I don't know, cure a disease maybe? Nah, they would rather rub pocket protectors and re-classify planets. Now text books across the world have to be changed.

I think America should say 'up yours' to these nerds and keep Pluto as planet. We're not backing down to the metric system and we're taking back Pluto, SUCKAAAAAAAAAS!

-HECK!

If Pluto is out, does this mean that Goofy has a shot?

Pluto is not a planted Blaaaaaa thats like saying Gore Did not invent the internet. Geesh the nerve of some folks.

I think there were WMD's on Pluto, that's why it's not a planet anymore.

-HECK!