Deep Impact's Principal Investigator, University of Maryland
Dawn Discovery Mission Project System Engineer Marc Rayman joins us to talk about this revolutionary spacecraft's journey to the two largest objects in the asteroid belt, Vesta and Ceres. Emily Lakdawalla's Q&A warns that volcano Olympus Mons on Mars may not be as dead as many have thought. Bruce Betts has the lowdown on what's up high, and a slightly disturbing random space fact. Also space headlines and a new space trivia contest.