Four Decades of Mars Exploration

Mars comes closer and closer. At the same time, five spacecraft are on their way to the Red Planet. Planetary Radio talks with Bruce Murray, planetary scientist and former Director of the Jet Propulsion Laboratory, about our fascination with Mars and the discoveries made by the spacecraft that have visited it over four decades, including the Mariner, Viking, Pathfinder, Mars Global Surveyor, and Odyssey spacecraft. Emily explains how Earth kept an atmosphere even as Mars lost one, and Bruce Betts discovers the similarity between opera singers and asteroid impacts.