Historic new guidelines approved by astronomers in Prague
This lineup shows the 12 planets that were proposed last week, with a wedge of the sun at far left. Ceres, Pluto, Charon and 2003 UB313 are barely visible. Now Charon will continue to be considered Pluto's satellite, and the three other worlds will be dubbed "dwarf planets" rather than full-fledged planets. The planets are drawn to scale, but without correct relative distances.
PRAGUE, Czech Republic - Leading astronomers declared Thursday that Pluto is no longer a planet under historic new guidelines that downsize the solar system from nine planets to eight.