Math and Science Educational Resource Availability, Part 1 - Nov 25, 2005
(08-24) 08:21 PDT -- Pluto was shafted by the world's astronomers today, demoted to the lowly status of "dwarf planet" and leaving the solar system with its original eight true planets plus countless other objects that must now be called "small solar system bodies." After more than two years of controversy that started when astronomer Mike Brown of Caltech announced his team had discovered a "10th planet" and was finding many more far out in the icy region billions of miles beyond the sun where comets are born, the International Astronomical Union voted a set of rules defining just what a planet is and what it's not.
Delegates to the Union meeting in Prague and representing 9,000 members decided that everything in the heavens that's massive enough for its own gravity to keep it roughly round is henceforth officially a planet.
Ceres, round and firm and fully packed, is the largest object in the asteroid belt where thousands of rocky chunks mostly orbit the sun between Mars and Jupiter, and many astronomers wanted to call it a full-fledged planet. But now it's only a dwarf planet, the IAU decided.
And Pluto's moon Charon, which the astronomers had first decided to link to Pluto and call a "double planet," also joined the lowly status of dwarf planet.
And so do all the objects Brown's team discovered -- the ones with unofficial names like Xena and Sedna and Quaoar -- they're all "dwarf planets" now, too.
Said Brown in a television interview with reporters from his office at Caltech in Pasadena:
"Scientifically, it's the right decision, it's sensible, it's acceptable and it's streamlined. There may be a lot of gnashing and wailing because Pluto is demoted, but Pluto overwhelmingly is not a planet, and it was a mistake to call it one when it was discovered more than 75 years ago."
E-mail David Perlman at email@example.com.
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