TheByte

Michael

Proposal would increase planets from 9 to 12

PRAGUE, Czech Republic (AP) -- Our solar system would have 12 planets instead of nine under a proposed "Big Bang" expansion by leading astronomers, changing what billions of schoolchildren are taught about their corner of the cosmos.

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 is not 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 should not 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 was 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 is 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 (113 kilometers) 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 would not qualify because the two bodies' common center of gravity lies below the surface of the Earth.

"There are as many opinions about Pluto as there are astronomers," Binzel said. "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 planetarium 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."

http://www.cnn.com/2006/TECH/space/0....ap/index.html

Rob

Ahhh, I wondered what they would call this new category of [tiny] planet, now I know ...a Pluton.

Michael

Astronomy has always boggled my mind. I think it is so beautiful yet mysterious to think that the universe is so big. Makes you wonder what things will be like 25 years from now or when we are able to travel space as if we were flying.

Carbon

I'd say that 25 years off would be a very optimistic outlook for casual interplanetary travel let alone interstellar travel.

Mirage77

Why would they want to do this, to increase our chances of survival by colonising the new planets?

I think this requires the decision of the whole world, not just astronauts.

Snake Vargas

"Because it's there"? The final frontier - to go where no one has gone before?

If it were up to the whole world, then nothing would ever get done. Just ask the UN

Seriously, even - the more people are involved, the more 'inertia' any project has - the tendency to remain in a state of constant velocity, including zero velocity. Innovation requires leadership and, yes, an ability to do what no one has done before. We can only hope that whatever happens is for the best!

As for 12 planets, well, it just makes things a little more confusing, then. I suppose that it's better to be confusing than inconsistent, though - maybe it would have been simpler to just throw Pluto out.

Michael

How big do you guys think the universe is? How is it possible to be that big in the first place?

Choleric

Beyond comprehension

siko

Well, space/time is infinite which is something we can't comprehend.

Michael

Based on the answers I got for my question what do you guys think about that? Not making this thread religious of course, do you think it can be defined in any way or form which would limit it?