Astronomical debate arises from redefinition of planets

BEIJING, Aug. 21 (Xinhuanet) -- Some 3,000 astronomers are now dabating in Prague, the Czech Republic, and expected to vote on Friday a newly proposed definition of "planet."

For the first time, a high-level committee of the International Astronomical Union was recommending the word "planet" be officially defined according to both scientific and historic standards -- every round object orbiting the sun is a planet, unless it orbits another planet.

The committee also said it is considering giving planet status to "a dozen or two" more objects discovered in recent years, including far away, planet-like bodies informally named Sedna, Quaoar, Orcus, Varuna and Ixion.

A planet, said the committee headed by Harvard astronomer Owen Gingerich, is an object that orbits a star like the sun; is massive enough so its own gravity keeps it roughly round; and isn't a satellite of another planet, like the moon.