What killed the mammoths? Near the end of the last ice age 13,000 years ago, these mighty beasts disappeared from North America together with some 35 other groups of mammals. For four decades, debate has raged over the cause of their abrupt demise. NOVA presents an in-depth investigation of a controversial new hypothesis which suggests that a massive impact from space could be the culprit, and also explores alternate theories.

Sinkholes have swallowed highways, apartment buildings, horses, camels, and even golfers with monster-size holes cracking the earth from Siberia to Louisiana. Filled with compelling eyewitness video of dramatic collapses, and following scientists as they explore the underlying forces behind these natural disasters, Nova travels the globe to investigate what it's like to have your world vanish beneath your feet.

From lobster claws and dog teeth to bee stings and snake fangs, every creature depends on a weapon. Showcasing astonishing wildlife cinematography, Extreme Animal Weapons investigates the riddle of outsize weaponry, uncovers a bold new theory about what triggers an animal arms race, and explores the secrets that underlie nature's battleground.

A history of the legendary Concorde, the passenger plane that flew from the late 70s until 2003 at twice the speed of sound. Designed and built by French and British engineers, the Concorde was the ultimate in speed and luxury for a select group of global jet setters, and the birthplace of many breakthroughs in aviation science. Ultimately, it was not sustainable because of enormous fuel consumption and high-ticket prices.