Quincy
08-24-2006, 10:23 AM
Astronomers meeting in the Czech capital have voted to strip Pluto of its status as a planet.
About 2,500 experts were in Prague for the International Astronomical Union's (IAU) general assembly.
Astronomers rejected a proposal that would have retained Pluto as a planet and brought three other objects into the cosmic club.
Pluto has been considered a planet since its discovery in 1930 by the American Clyde Tombaugh.
The vote effectively means the ninth planet will now be airbrushed out of school and university textbooks.
The decision was made at a meeting of the International Astronomical Union (IAU) in the Czech capital Prague.
"The eight planets are Mercury, Earth, Venus, Mars, Jupiter, Saturn, Uranus and Neptune," said the IAU resolution, which was passed following a week of stormy debate.
The IAU's proposal to raise the number of planets in the Solar System to 12, adding the asteroid Ceres, Pluto's "moon" Charon and the distant object known as 2003 UB313, met with opposition.
Pluto's status has been contested for many years as it is further away and considerably smaller than the eight other planets in our Solar System.
Since the early 1990s, astronomers have found several other objects of comparable size to Pluto in an outer region of the Solar System called the Kuiper Belt.
Some astronomers believe Pluto belongs with this population of small, icy "Trans-Neptunians", not with the objects we call planets.
Allowances were once made for Pluto on account of its size. At just 2,360km (1,467 miles) across, Pluto is significantly smaller than the other planets. But until recently, it was still the biggest known object in the Kuiper Belt.
That changed with the discovery of 2003 UB313 by Professor Mike Brown and colleagues at the California Institute of Technology (Caltech). After being measured with the Hubble Space Telescope, it was shown to be some 3,000km (1,864 miles) in diameter, making it larger than the ninth planet.
http://news.bbc.co.uk/1/hi/world/5282440.stm
About 2,500 experts were in Prague for the International Astronomical Union's (IAU) general assembly.
Astronomers rejected a proposal that would have retained Pluto as a planet and brought three other objects into the cosmic club.
Pluto has been considered a planet since its discovery in 1930 by the American Clyde Tombaugh.
The vote effectively means the ninth planet will now be airbrushed out of school and university textbooks.
The decision was made at a meeting of the International Astronomical Union (IAU) in the Czech capital Prague.
"The eight planets are Mercury, Earth, Venus, Mars, Jupiter, Saturn, Uranus and Neptune," said the IAU resolution, which was passed following a week of stormy debate.
The IAU's proposal to raise the number of planets in the Solar System to 12, adding the asteroid Ceres, Pluto's "moon" Charon and the distant object known as 2003 UB313, met with opposition.
Pluto's status has been contested for many years as it is further away and considerably smaller than the eight other planets in our Solar System.
Since the early 1990s, astronomers have found several other objects of comparable size to Pluto in an outer region of the Solar System called the Kuiper Belt.
Some astronomers believe Pluto belongs with this population of small, icy "Trans-Neptunians", not with the objects we call planets.
Allowances were once made for Pluto on account of its size. At just 2,360km (1,467 miles) across, Pluto is significantly smaller than the other planets. But until recently, it was still the biggest known object in the Kuiper Belt.
That changed with the discovery of 2003 UB313 by Professor Mike Brown and colleagues at the California Institute of Technology (Caltech). After being measured with the Hubble Space Telescope, it was shown to be some 3,000km (1,864 miles) in diameter, making it larger than the ninth planet.
http://news.bbc.co.uk/1/hi/world/5282440.stm