The Vikings didn’t invent crucible steel, so where did it come from? Many experts believe that the Volga trade route supplied Vikings with prized crucible steel from the Middle East, where people were more practiced in the art of forging it.

Military historian Mike Loades explores the weapons that the ancient Egyptians used in war. Then, he takes them on a one-of-a-kind chariot ride.

Protective armor was a necessity in Egyptian chariot warfare. Military historian Mike Loades explains what made it so strong.

While testing Curiosity’s parachute in the world’s largest wind tunnel, JPL scientists and engineers were confounded by a failed trial run. The parachute had never failed to open in the past, so why this strange anomaly? By replicating the error and analyzing it in high-resolution footage, they were able to pinpoint the problem.

An innovative computer-based handwriting analysis technique helps NOVA dig deeper into the kidnapping of Charles Lindbergh’s baby. But while the results might sway investigators in a certain direction, they certainly aren’t definitive.

A University of Pennsylvania lab is developing tiny drones that sense their environment.

A DARPA researcher describes what would constitute a breakthrough in UAV autonomy.

The X-47B prototype can land on a flight deck without input from a pilot.

A UAV pilot describes what it’s like to conduct a drone strike.

An engineer describes the next-generation surveillance sensor for UAVs, called ARGUS.

Until recently, scientists have encountered scant evidence of Neanderthal ritual or religious practice. A new discovery, though, suggests that Neanderthals—much like today’s bear hunters—ceremoniously cut off panther paws and kept them as trophies.

Virtual autopsies paint remarkably informative pictures of a body's post-mortem condition. Watch Dr. Anders Persson and his team get under the virtual skin of a victim in order to uncover more information about his death.

The world’s first industrial process likely began with the Neanderthals. In this video, watch as NOVA reenacts the Neanderthal technique of pitch extraction through a complex called dry distillation.

"Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. Produced in extensive consultation with NASA scientists, NOVA takes data from earth-observing satellites and transforms it into dazzling visual sequences, each one exposing the intricate and surprising web of forces that sustains life on earth.

Volcanoes can come in many shapes and sizes. PRODUCTION CREDITS Produced, animated, and edited by Anna Rothschild Original Footage ©WGBH Educational Foundation For a full list of credits, see http://www.pbs.org/wgbh/nova/earth/meet-volcanoes.html

Thrihnukagigur crater is the only place on Earth where the anatomy of a volcano can be studied from the inside. When geologists journeyed into its heart, they discovered that a network of fissures links together distant volcanoes.

Expert investigators reexamine one of the greatest murder mysteries of all time.

A team of archaeologists, engineers, woodworkers, and horse trainers join forces to build and test two highly accurate replicas of Egyptian royal chariots. They discover astonishingly advanced features, including spoked wheels, springs, shock absorbers, anti-roll bars, and even a convex-shaped rear mirror, leading one of them to compare the level of design to the engineering standards of 1930's.

Meet a new breed of flying robots, from tiny swarming vehicles to giant unmanned planes.

Over 60,000 years ago, the first modern humans—people physically identical to us today—left their African homeland and entered Europe, then a bleak and inhospitable continent in the grip of the Ice Age. But when they arrived, they were not alone: the stocky, powerfully built Neanderthals had already been living there for hundred of thousands of years.