Pluto's planet status under threat
Monday, 14 Aug 2006 13:44
Pluto may no longer be known as a planet
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Pluto may no longer be classified as a planet following a debate by astronomers at the International Astronomical Union.
Roughly 3,000 astronomers and scientists are meeting in Prague this week for the union and are expected to determine whether Pluto is a planet under newly defined terms.
The planet, which was first discovered in 1930 and is the farthest away from the sun, is considerably smaller than the other eight planets in our solar system.
By defining exactly what a planet is, scientists could be forced to downgrade Pluto's status and promote 14 other bodies.
Larger bodies than Pluto have been discovered at the edge of the solar system, including a rocky object known officially as 2003 UB313 that was identified by Professor Mike Brown at the California Institute of Technology.
The object has been measured by the Hubble space telescope as having a diameter of 1,490 miles, beating Pluto's diameter by roughly 70 miles.
Alan Stern, who heads the Colorado-based space science division of the Southwest Research Institute of San Antonio, told the Associated Press: "It's time we have a definition.
"It's embarrassing to the public that we as astronomers don't have one."
Some scientists have suggested that there are separate categories within the planet definition, such as terrestrial, giant and dwarf.
"Pluto is not worthy of being called just a plain planet," said Alan Boss, an astrophysicist at the Carnegie Institution in Washington, DC.
"But it's perfectly fine as an ice dwarf planet or a historical planet."
The meeting of the International Astronomical Union begins today and is expected to last for 12 days.