Dinosaur Tracking: Snowbirds From Another Era

It's commonly known that a single asteroid set off the dinosaurs' extinction. Even more destructive than its impact was the chain of events it set into motion.

How a Single Asteroid Wiped Dinosaurs Off This Planet (1:14)

One highly influential ancient Middle Eastern civilization established some of the essential systems we still use today. Think you know which it is?

Who Decided to Put 60 Seconds in a Minute? (2:33)

Thousands of massive stone monuments, known as Moai, preside over Easter Island. The way they were carved, using only stone tools, seems unfathomable.

How Were Easter Island's Gigantic Statues Actually Carved? (4:11)

Green tree vipers can kill in the dark. With special heat-sensing abilities, they can find prey that's all but invisible.

A Pit Viper's Sixth Sense (2:03)