Astronomers kick Pluto out of cosmic club

Not open for further replies.


Premium Subscriber
Jan 26, 2005
Navasota, TX.
Astronomers kick Pluto out of cosmic club

10:09 AM CDT on Thursday, August 24, 2006

Associated Press

PRAGUE, Czech Republic - Pity poor Pluto: After decades of being confused with a cartoon dog and enduring ridicule as a puny poser, the solar system's consummate cling-on has officially lost its status as a planet.


Mercury, Venus, Mars, Earth, Jupiter, Saturn, Neptune, Uranus and Pluto (l-r)

Leading astronomers have declared that Pluto is no longer a planet in approving new guidelines that downsize the solar system from nine planets to eight. Unfortunately for the ninth rock from the sun, they seemed intent on demoting Pluto to a "dwarf" -- a step below Earth and the seven other "classical" planets.

Under pressure from opponents, the organization backed off its original plan to retain Pluto's status and bring three other objects into the cosmic club.

If the 2,500 astronomers from 75 nations meeting in Prague agree, Earth's neighborhood will officially shrink to eight planets from the traditional nine.

"Some say, 'No, Pluto is a nice planet"' and should remain one, said Japanese astronomer Junichi Watanabe, said. "But this is a natural way to draw a line."


Did Pluto deserve to be demoted?

No: Books, old school projects will be obsolete!

Yes: It's not worthy

Not sure: Let's ask Goofy

View Results
The resolution by the group, the official arbiter of heavenly bodies, defines a planet as "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."

Anything less would be either a dwarf planet, as in Pluto's case, or a "small solar system body," which would cover many asteroids, comets or other natural satellites.

It was unclear how Pluto's demotion could affect the mission of NASA's New Horizons spacecraft, which earlier this year began a 9 1/2-year journey to the oddball object to unearth more of its secrets.

Astronomers want to draw a sharp distinction between the eight "classical planets" -- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune -- and Pluto, which is smaller than Earth's moon, no larger than many objects in its area and has an eccentric orbit.

Joining it as dwarfs would be its largest moon, Charon; the asteroid Ceres, which was a planet in the 1800s before it got demoted; and a recently discovered object known as 2003 UB313 and nicknamed Xena.

Just a week ago, all three objects were poised to become planets under an initial draft definition that would have created a new class of planetary objects to be dubbed "plutons."

But that idea left many astronomers cold, triggering days of spirited and sometimes combative debate that led to the latest proposal to dump Pluto.

Many believe there's simply no scientific justification to grant full planet status to most of what's floating in the vast sea of rocks that reside in the Kuiper Belt -- a mysterious, disc-shaped zone beyond Neptune containing thousands of comets and planetary objects.

Forget the term "pluton" -- it's already history, replaced by "plutonium object."

The IAU backed off after getting dozens of objecting e-mails from scientists, including geologists who pointed out -- somewhat embarrassingly to astronomers -- that "pluton" is already a prominent term in volcano science for deep igneous rock formations.

"What were they thinking?" said Allen F. Glazner, a geologist at the University of North Carolina. "It would be like botanists trying to distinguish between trees and shrubs and coming up with the term 'animal."'

Suddenly, the future looks dim for much-maligned Pluto, named for the God of the underworld.

Its underdog status has inspired scores of tributes, including one by New York folk singer Christine Lavin that laments: "I guess if Pluto showed up at a planet convention, the bouncer at the door might have to ban it."

Online at:
Not open for further replies.