NOVA - What2Watch

A new five-part, four-week docu-series called "The Planets" launches tonight with "Inner Worlds," an episode that uses footage and data collected from space missions, plus computer-generated sequences, to explore the four planets closest to our sun: Mercury, Venus, Earth and Mars. All four of these rocky planets were born around the same time, from the same material, yet only one today thrives with life. The second episode, "Mars," follows immediately and examines the fascinating "red planet."