ENCORE While the Kepler spacecraft hunts for habitable planets beyond the solar system, weve let one of our own planets slip away Find out ... tags: Alan_SternAndrew_FraknoiAndy_FraknoiCarolyn_PorcoCassiniEducationGalilleo

While the Kepler spacecraft hunts for habitable planets outside our galaxy, weve let one of our own planets slip away Find out why Plutos ... tags: Alan_SternAndrew_FraknoiAndy_FraknoiCarolyn_PorcoCassiniEducationGalilleo