Back to School: 12 Planets?

[Aaron_Westler 0]

August 16, 2006 - The universe really is expanding! Astronomers are proposing to rewrite the textbooks to say that our solar system has 12 planets rather than the nine memorized by generations of schoolchildren.

Much-maligned Pluto would remain a planet and its largest moon plus two other heavenly bodies would join Earth's neighborhood under a draft resolution to be formally presented Wednesday to the International Astronomical Union, the arbiter of what is and isn't a planet.

 

"Yes, Virginia, Pluto is a planet," quipped Richard Binzel, a professor of planetary science at the Massachusetts Institute of Technology.

 

The proposal could change, however: Binzel and the other nearly 2,500 astronomers from 75 nations meeting in Prague to hammer out a universal definition of a planet will hold two brainstorming sessions before they vote on the resolution next week. But the draft comes from the IAU's executive committee, which only submits recommendations likely to get two-thirds approval from the group.

 

Besides reaffirming the status of puny Pluto whose detractors insist it shouldn't be a planet at all the new lineup would include 2003 UB313, the farthest-known object in the solar system and nicknamed Xena; Pluto's largest moon, Charon; and the asteroid Ceres, which was a planet in the 1800s before it got demoted.

 

The panel also proposed a new category of planets called "plutons," referring to Pluto-like objects that reside in the Kuiper Belt, a mysterious, disc-shaped zone beyond Neptune containing thousands of comets and planetary objects. Pluto itself and two of the potential newcomers Charon and 2003 UB313 would be plutons.

 

Astronomers also were being asked to get rid of the term "minor planets," which long has been used to collectively describe asteroids, comets and other non-planetary objects. Instead, those would become collectively known as "small solar system bodies."

 

If the resolution is approved, the 12 planets in our solar system listed in order of their proximity to the sun would be Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon, and the provisionally named 2003 UB313. Its discoverer, Michael Brown of the California Institute of Technology, nicknamed it Xena after the warrior princess of TV fame, but it likely would be rechristened something else later, the panel said.

 

The galactic shift would force publishers to update encyclopedias and school textbooks, and elementary school teachers to rejigger the planet mobiles hanging from classroom ceilings. Far outside the realm of science, astrologers accustomed to making predictions based on the classic nine might have to tweak their formulas.

 

Even if the list of planets is officially lengthened when astronomers vote on Aug. 24, it's not likely to stay that way for long: The IAU has a "watchlist" of at least a dozen other potential candidates that could become planets once more is known about their sizes and orbits.

 

"The solar system is a middle-aged star, and like all middle-aged things, its waistline is expanding," said Jack Horkheimer, director of the Miami Space Transit Planetarium in the United States and host of Public Broadcasting's Stargazer television show.

 

Opponents of Pluto, which was named a planet in 1930, still might spoil for a fight. Earth's moon is larger; so is 2003 UB313 (Xena), about 70 miles wider.

 

But the IAU said Pluto meets its proposed new definition of a planet: any round object larger than 800 kilometers (nearly 500 miles) in diameter that orbits the sun and has a mass roughly one-12,000th that of Earth. Moons and asteroids will make the grade if they meet those basic tests.

 

Roundness is key, experts said, because it indicates an object has enough self-gravity to pull itself into a spherical shape. Yet Earth's moon wouldn't qualify because the two bodies' common center of gravity lies below the surface of the Earth.

 

"People were probably wondering: If they take away Pluto, is Rhode Island next?" Binzel quipped. "There are as many opinions about Pluto as there are astronomers. But Pluto has gravity on its side. By the physics of our proposed definition, Pluto makes it by a long shot."

 

IAU President Ronald D. Ekers said the draft definition, two years in the making, was an attempt to reach a cosmic consensus and end decades of quarreling. "We don't want an American version, a European version and a Japanese version" of what constitutes a planet, he said.

 

Neil deGrasse Tyson, director of the Hayden Planetarium at New York's American Museum of Natural History miscast as a "Pluto-hater," he contends, merely because Pluto was excluded from a solar system exhibit said the new guidelines would clear up the fuzzier aspects of the Milky Way.

 

"For the first time since ancient Greece, we have an unambiguous definition," he said. "Now, when an object is debated as a possible planet, the answer can be swift and clear."

 

AP Science Writers Alicia Chang in Los Angeles and Seth Borenstein in Washington contributed to this story.

 

On the Net:

 

International Astronomical Union, iau.org

[LoAmi 0]

I was entertained when I saw that this story made the front page of at least one major American newspaper.

 

It really doesn't matter very much what gets decided. All that's being discussed is a matter of categorization. There's no new science here. The real new science involved was the discovery of large Kuiper Belt Objects other than Pluto and Charon (the Kuiper Belt is kind of like a second asteroid belt beyond Neptune).

 

Nomenclature-wise, I would rather demote Pluto/Charon to the status of "large" double KBO than have every large asteroid become a "planet" and torture elementary school teachers every few years to have to come up with a new mnemonic for the order of the planets. :-)

[will_marx 0]

Nomenclature-wise, I would rather demote Pluto/Charon to the status of "large" double KBO than have every large asteroid become a "planet" and torture elementary school teachers every few years to have to come up with a new mnemonic for the order of the planets. :-)

 

But Lo, that's what elementary school teachers are supposed have done to them by the "experts". It keeps them honest, and researching after they get their tenure, instead of using the same old boring theories of education that haven't works since the 50's

[LoAmi 0]

My point has less to do with elementary school teachers than to do with the nature of the fact itself.

 

This isn't like a major new theory that requires rethinking old assumptions. It's just a matter of names, which is rather unimportant.

[Sendai Riko 0]

As usual, when there isn't anything exciting going on in a scientific discipline, they have to bicker over semantics. It's one of the unfortunate sides to science, but seemingly inevitable with human beings being what they are. Whichever way it goes, it's not really important one way or the other so long as we point them out and say that they exist, not what they are.

[Dumbass 0]

["People were probably wondering: If they take away Pluto, is Rhode Island next?" Binzel quipped.

:D

 

Personally I think they should keep 2003 UB313 as tbe name.

Edited August 17, 2006 by Dumbass

[Col. C.E. Harper 0]

It's not just Pluto/Charon and "Xena" -- there's at least 2 other Kuiper Belt Objects vying for planetary status: Sedna and Quaoar, as well as a slightly smaller one called Orcus.

 

Personally, I think nine is too entrenched to change. But it's pretty cool stuff all the same.

[Travis Kroells 0]

I honestly stopped counting after Uranus. The rest seem insignificant...

[DrAndreaKnollwatcher 0]

But Lo, that's what elementary school teachers are supposed have done to them by the "experts". It keeps them honest, and researching after they get their tenure, instead of using the same old boring theories of education that haven't works since the 50's

Yeah, like the bogus theory that Oswald shot Kennedy, that they still shove down kids throats.

 

Thanks for the chance at a shameless plug, Will. I owe ya one. =0]

[will_marx 0]

Yeah, like the bogus theory that Oswald shot Kennedy, that they still shove down kids throats.

 

Thanks for the chance at a shameless plug, Will. I owe ya one. =0]

Heh. I never thought Oswald shot Kennedy. The proof is right there in the Zabruder film. If JFK was shot from behind, he would have gone down and forward, not down and back. And while training to go to Iraq, we had to shoot pop-up targets, let me tell you, even trying to hit a man-shaped figure at 300m is difficult. But a headshot? Only military trained snipers are that accurate. And Oswald was no sniper.

 

::getting off his soapbox on Who Killed the Kennedies:: Please to meet you; hope you guess my name...

 

So, any new news on whether or not we'll be adding a TV character to our heavenly bodies?

[DrAndreaKnollwatcher 0]

Heh. I never thought Oswald shot Kennedy. The proof is right there in the Zabruder film. If JFK was shot from behind, he would have gone down and forward, not down and back. And while training to go to Iraq, we had to shoot pop-up targets, let me tell you, even trying to hit a man-shaped figure at 300m is difficult. But a headshot? Only military trained snipers are that accurate. And Oswald was no sniper.

 

::getting off his soapbox on Who Killed the Kennedies:: Please to meet you; hope you guess my name...

 

So, any new news on whether or not we'll be adding a TV character to our heavenly bodies?

 

One very intriguing student of the assassination is Steven Rivele. He has a theory about who killed Kennedy and how, which I think is right on. We still dont know why (although, I do have some theories, of course), but we know who.

 

OK, I know this thread isnt about JFK. But, A9 can I start one?! heh heh =0]