NOVA: Is There Life on Mars?

An in-depth look at NASA's Mars missions observes earthbound scientists directing the rovers, details the discovery of subsurface ice and examines whether the evidence suggests past or present life on the Red Planet. Included: what may have caused Mars to become such an inhospitable planet, and why its northern and southern hemispheres are so different; interviews with Harvard paleontologist Andrew Knoll and NASA planetary scientist Christopher McKay.