What goes on behind-the-scenes to get the manners of 1900s Britain exactly right on Downton Abbey? Discover the secrets of how the aristocratic set dined and dressed, how they married and made money, how they interacted with the servants, and above all why they behaved as they did. Includes revealing interviews with leading cast members.

Long before the Deepwater Horizon explosion in the Gulf, BP was widely viewed as a company that valued deal-making and savvy marketing over safety, a 'serial environmental criminal' that left behind a long trail of problems, deadly accidents, disastrous spills, countless safety violations, which many now believe should have triggered action by federal regulators.

Americans own 73 million dogs and 90 million cats, considering them best friends, family members, and even children. Relationships with cats and dogs are some of the longest and most intimate of our lives. Why are we attached? Animal behavior experts, evolutionary biologists, veterinarians, and pet owners get personal in a series of interviews and stories that are insightful, funny, heartwarming, and life-changing.

A remarkable new story is unfolding in the Arctic. As the ice melts and polar bears struggle to survive, another animal is taking over the polar bear's once dominant role as top predator. An ever-increasing number of killer whales are appearing in Arctic waters. As the polar bear's world is shrinking, the orca's is growing.

Tells the compelling story of the author's life. Through dramatic reenactments and interviews with top Mitchell scholars, Margaret Mitchell emerges as a complex and fascinating woman who had much in common with her iconic creation, Scarlett O'Hara.

In 2013, a particularly massive chunk of ice and rock is hurtling towards the Atlantic Ocean. The object's size will fascinate billions and should create the space show of the century. Follow scientists on the trail of the once-in-lifetime comet ISON and explore the cultural obsession with these celestial visitors.

On February 15th, car cameras and cellphones captured a blinding streak that flashed across the sky over Russia's Ural Mountains, followed by an explosion that injured some 1,500 people. The meteor, weighing around 10,000 tons, was the largest object to burst in the atmosphere since 1908. Within days, NOVA crews were in Russia following impact scientists as they hunted for debris from the explosion and clues to the meteor's origin.

NASA's Kepler mission has identified more than 3,500 potential planets orbiting stars beyond the sun. Some of them, like a planet called Kepler-22b, might even be able to harbor life. Combining animation with input from expert astrobiologists, the program 'builds' aliens from the ground up.

Learn how to combat the effects of aging in just five minutes a day. Each short period of stretching, strength-building, and specialized breathing contributes to greater flexibility, strength, and mental clarity. After years spent teaching and practicing, Peggy has designed a way of incorporating yoga into our daily lives.

Take a global tour in four themed episodes, answering the simplest questions about the complex forces that shape our planet. Why is water blue? How can a shape defy gravity? Why do bees make hexagonal honeycombs? And how do these things affect our own lives? Discover what lies beneath Earth's startling beauty as we reveal the secrets of our cosmos and the natural forces that govern everything within it.