300 2012

The Vikings were among the fiercest warriors of all time. Yet only a select few carried the ultimate weapon of their era: the feared Ulfberht sword. Fashioned using a process that would remain unknown to the Vikings' rivals for centuries, the Ulfberht was a revolutionary high-tech tool as well as a work of art.

Why go back to Mars? Far from dead, Mars holds untold potential. Nearly half a century of Mars exploration has yielded tantalizing clues that Mars may once have harbored life—and may harbor it still. The extraordinary landing of a revolutionary rover named Curiosity—which successfully touched down inside the Gale Crater—means we have wheels down on the planet once again, in the form of the most sophisticated robot ever to rove the Mars surface. Will NASA's bold mission and this marvel of technology answer some of our biggest questions and usher in a new golden age of exploration? NOVA goes behind the scenes on NASA’s quest to solve the riddles of the red planet.

In a special investigation in collaboration with Marketplace, FRONTLINE travels to the remote epicenter of the campaign finance debate for a tale of money, politics, and intrigue. How has the Supreme Court's Citizens United decision changed campaigns in America?

Quite possibly the biggest star that television has ever produced, Johnny Carson was seen by more people on more occasions than anyone else in American history. Over the course of his 30-year run on The Tonight Show, Carson interviewed 23,000 guests in 4,531 episodes. Yet he remained a very private man who rarely gave interviews himself.

Singers found on the Internet are chosen to be opening acts for top performers and have just five days to prepare for the concert. As the series begins, an unsuspecting girl is chosen to open for Rod Stewart.

Is darkness becoming extinct? When filmmaker Ian Cheney moves from rural Maine to New York City and discovers streets awash in light and skies devoid of stars, he embarks on a journey to America’s brightest and darkest corners, asking astronomers, cancer researchers and ecologists what is lost in the glare of city lights.