Watch NOVAs

The Spy Factory (Feb. 2009)

Examine the high-tech eavesdropping carried out by the National Security Agency and the pitfalls of surveillance in an age of terrorism. Watch now (50 mins.)

The Incredible Journey of the Butterflies (Jan. 2009)

Follow the 2,000-mile migration of monarchs to a sanctuary in the highlands of Mexico. Watch now (50 mins.)

The Big Energy Gamble (Jan. 2009)

Can California's ambitious plan to cut greenhouse gases actually succeed? Watch now (50 mins.)

Is There Life on Mars? (Dec. 2008)

The decades-long search for life on the Red Planet heats up with the discovery of frozen water. Watch now (50 mins.)

Ocean Animal Emergency (Nov. 2008)

Wildlife veterinarians struggle to save injured seals and sea lions on the California coast. Watch now (50 mins.)