Mars Express Confirms Lots of Polar Ice! Where's the Rest?

Jet Propulsion Lab Principal Scientist Jeffrey Plaut is also a Co-Principal Investigator on the MARSIS radar carried by the European Space Agency's Mars Express Orbiter. He talks about what the instrument has learned about the 2.5-mile thick ice at the Martian south pole and about where the rest of the Red Planet's once vast amount of surface water may have gone. Emily Lakdawalla's Q&A names the winner of a race to the stars. Bruce Betts fears the black helicopters as he tells Mat Kaplan about the night sky and announces a new space trivia contest.