Intrepid zoologist Nigel Marven thought he knew all about the world's most dangerous fish from his encounters with sharks; but that was before he went face-to-face with piranhas. Nigel travels through the waterways of South America to find out the truth.

Take a unique behind-the-scenes look at the latest models being developed at NASA. The Ares, a futuristic new rocket, is set to revolutionise space exploration.

The Cretaceous Period spawned dinosaurs with a savage combination of speed, eyesight, brainpower and razor-sharp implements. Science reveals their secrets.

Cody and Dave must use items they salvage from their life raft to find shelter, build a fire and find food and water when they arrive on a deserted island off the coast of Nova Scotia in the dead of winter - showing what it takes to survive.

Why does the universe exist and why does it follow rules and laws? From the discovery of gravity to the development of string theory, Hawking explores the principles of the cosmos.