Kepler Principal Investigator William Borucki returns with details of the spacecraft's possible discovery of more than 1,200 worlds circling other stars. Many are Earth-sized, many are in the habitable zone." Emily Lakdawalla reports on the spectacular flyby of comet Tempel 1 just completed by Stardust NEXT. Bill Nye the Planetary Guy reports in from Georgia Tech with concern about funding for climate change research pitted against human spaceflight. Bruce Betts and Mat Kaplan give away Solar System for iPad and kick off another What's Up? space trivia contest."