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Astronomers Debate Pluto’s Planetary Status

Members of the International Astronomical Union voted in August to reclassify Pluto as a "dwarf planet." Many astronomers, however, are unhappy with the demotion -- they question its scientific validity and the way the decision was made.

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  • BETTY ANN BOWSER, NewsHour Correspondent:

    Educators like Kris McCall, who runs the Sudekum Planetarium in Nashville, have a challenge.

  • KRIS MCCALL, Educator, Sudekum Planetarium:

    How many planets are there in our solar system, nine, eight? Anybody have a different answer?


    There was already a show there called "Nine Planets and Counting," so McCall had to do a quick rewrite.


    Why should Pluto be a planet?


    Because, back in the '50s, they told us it was. I was raised that way, and I'd hate to see it be gone now after all those years.


    The downgrading of Pluto to a new status called dwarf planet was decided by a vote of less than 400 of the International Astronomical Union's 10,000 members at a meeting in Prague.

    For the first time, they defined a planet, an object in the solar system that must be round, must orbit a star, and must clear out its neighborhood. In other words, it must not share its orbit around the sun with any other large objects. They said Pluto didn't fit the bill because it had many other objects nearby.

    The decision sparked a revolt among planetary experts, like these at a recent meeting of hundreds of astronomers and astrophysicists in Pasadena.