Committee recommends Pluto's planet status stay intact

WASHINGTON -- "Our sidewalk dodged a bullet," said Harvey Leifert, spokesman for the American Geophysical Union, offering his take on the great solar system shake-up of 2006.

When the Washington-based not-for-profit built its headquarters about a decade ago, someone got the idea to dress up the sidewalk out front with inlaid bronze markers representing the planets, that beloved gang of nine: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.

But right now, more than a thousand of Earth's most pre-eminent stargazers are gathered in Prague, Czech Republic, under the auspices of the International Astronomical Union. They're debating whether oddball Pluto (the smallest planet, most distant from the sun, the one trapped in a misshapen orbit that takes 247 years per revolution) should be booted from the club. A vote is scheduled for Thursday.

The IAU's "Planet Definition Committee" has recommended Pluto not be busted from planet status.

But a new definition was offered in Prague on Tuesday, according to the New York Times. That definition would set up a three-tiered classification scheme with eight "planets"; a group of "dwarf planets" that would include Pluto, the asteroid Ceres, the newly discovered UB 313 (nicknamed Xena) and many other icy balls in the outer solar system; and thousands of "smaller solar system bodies," like comets and asteroids.

Last week, an IAU executive committee unveiled a proposal -- defining planets as solar system objects which do not orbit anything besides the sun and that have been shaped into a sphere by their own gravity. The proposal added three planets to the solar system: Ceres, UB 313 and Pluto's moon Charon (making Pluto and Charon a mutually revolving "double planet").

As radio telescopes peer deeper into space, as unmanned probes push farther into the unknown, scientists are pulling back the curtain on those beyond-Pluto nooks of the solar system. They're turning out to be more densely populated than almost everyone imagined.

The detritus of the system is out there swirling in the void. Hundreds of thousands of objects elbow for room in the Kuiper Belt, beyond Neptune; even more flotsam may pinball around the hazy domain of the hypothesized Oort Cloud, beyond Pluto.

It's easy to wrap one's mind around the concept of nine billiard ball-like planets locked in an eternal dance with the sun. But potentially dozens of new planets?

Millions of textbooks are on the verge of requiring major revision. Julia Osborne, science editorial director for scholastic publisher Pearson Prentice Hall, says breaking-news changes will be posted on the company's "Planet Diary" Web site and printed in supplemental inserts, then formally phased in as hardback editions are scheduled for updating. That can take time. North Carolina, for example, isn't due to purchase new science textbooks until 2010.

"I have three editors that are really rabid about this. There are people that are really excited," says Osborne. "It'll be a great way to start the (school) year. 'Science is always the same.' No, it's changing! This is an opportunity for teachers to present that excitement."

It isn't, however, much of an opportunity for making windfall profits. As Jay Diskey, executive director of the school division of the Association of American Publishers, says, "The people who make money are the people who make T-shirts. It's certainly not textbook publishers."

Leifert is pleasantly surprised at the buzz being generated by the deliberations in Europe: front-page news articles, polls, online news group chatter. But he's not sure the cause of it: "You'll have to talk to a psychologist about that."

Or maybe amateur astronomers.

The Howard Astronomical League holds monthly meetings at the Howard County Department of Recreation and Parks building in Columbia, Md. About 40 people showed up Thursday night.

Most of them are aware the Pluto controversy has been bubbling for nearly 20 years. Most also know the high priests in Prague have proposed a classification system: Eight original planets will be designated "classical" planets, while Pluto becomes the namesake of a new subcategory called "plutons," which include three charter nominees: Ceres, the super asteroid that's wedged between Mars and Jupiter; Charon, Pluto's largest moon; and 2003 UB313 or "Xena," the unofficially named deep-space body discovered last year.

"It's something of a cultural debate," says Marc Feuerberg, volunteer president of the league. "It's not much of a scientific debate."

Bob Chapman, a retired Honeywell International astronomer, doesn't like the notion of elevating Ceres to a planet.

"Let's keep it an asteroid," he says. "On the other hand, I like the idea of a pluton."

Dave Illig isn't buying any of the reclassification logic. "I have reservations about this," he tells the group. "This is discrimination by distance. It really is."

"I grew up with nine planets, and it's hard to let go of that emotionally," says Teresa Palomar, a high school math teacher at the meeting. "But children will adapt. If we go with 12 planets, 50 years from now children will look back fondly on those 12 planets."

If Pluto were discovered today, as opposed to 1930, the opinion of most professional and amateur astronomers is that it would not receive serious planet consideration. But back then, nobody realized just how aberrant an ice ball it was, that it marked the gateway to deep space. Pluto, therefore, entered the textbooks and the public consciousness as a full-fledged planet.

Even minor traditions die hard. Several years ago Neil deGrasse Tyson, director of the Hayden Planetarium at the American Museum of Natural History in New York, wrote an essay criticizing what he saw as the Pluto myth. He noted, among other things, that its orbit is tilted at a different angle than other planets and that it's primarily made of ice, not rock or gas.

His remarks didn't sit well with a certain constituency.

Tyson later remarked, "My files are overfilled with hate mail from elementary students." ,

There's interest in Ceres, Charon and 2003 UB313, but nothing on the scale of Pluto - which was the only planet discovered in the 20th century but which very few people have seen.

Yet according to Bruce Betts, director of projects at the Planetary Society, a Pasadena, Calif., nonprofit organization that promotes space exploration, "Pluto tugs at the heartstrings of people."