He was one of the last two humans to walk on the moon. Geologist, engineer, entrepreneur and former US Senator Harrison Schmitt talks about the legacy of Apollo, and his current dream of clean, cheap power from the moon's supply of Helium-3. Emily Lakdawalla is looking for craters around our solar system, because they have stories to tell. Bruce Betts knows What's Up! in the night sky, and offers our newest space trivia contest.