Solving Cosmic Mysteries Deep Under the Earth

Art McDonald is Director of the Sudbury Neutrino Observatory, two kilometers deep in a nickel mine in northern Canada. He talks about this amazing instrument and the mysteries it has solved. Emily Lakdawalla's Q&A is about how NASA worked to protect Mars from stowaway microbes on the Mars Exploration Rovers. What's Up with neutrino nut Bruce Betts looks at the current night sky, and presents another chance to wina Planetary Radio t-shirt.