Pluto Gets New Name, as Does "Xena"

Kimberly Johnson
for National Geographic News
September 15, 2006

Pluto is now just a number, officially speaking.

The former planet has been dubbed asteroid number 134340 to reflect its new status as a "dwarf planet."

Pluto was ousted from the official pantheon of planets late last month when the International Astronomical Union, the governing authority over celestial bodies, finalized the first official definition of "planet" at a meeting in Prague in the Czech Republic.

According to the IAU, a planet is an object that orbits the sun, forms itself into a sphere, and has enough gravitational pull to clear its path of space debris.

The move downgraded Pluto and finalized a long-running debate about Pluto's planetary status. Unlike the eight planets once considered its peers, Pluto does not sweep its neighborhood clear and has an orbit that is much more eccentric.

Following the revised conventions, the IAU's Minor Planet Center, which tracks asteroids and comets, gave Pluto the new designation on Wednesday to add it to the standard catalog of numbered objects with well-determined orbits.

But that doesn't mean people will start referring to Pluto differently.

"There is no intention of changing the name," IAU President Catherine Cesarsky said. "The number assigned is just for tables."

Also on Wednesday, the IAU gave an official name to 2003 UB313, a distant icy rock larger than Pluto.

In a tongue-in-cheek choice, 2003 UB313 will now be called Eris, after the Greek goddess of discord and strife. Eris' discovery last year reignited the debate over the definition of "planet" that eventually led to Pluto's ouster.

2003 UB313 had previously been nicknamed Xena by its discoverer—astronomer Michael Brown of the California Institute of Technology in Pasadena—after the title character in the television show Xena: Warrior Princess.

"Now Pluto is not alone anymore. It has Eris," Cesarsky said.

Continued on Next Page >>




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