End of the Big Beasts
Overhunting, climate change, disease, and now a comet. What did kill off the megafauna?

Extraordinary Artifacts
Ten exquisite Clovis stone tools reveal the artistry of America's early flintknappers.

Modeling a Comet Airburst
In this video clip, see why an explosion three miles above Earth would act like a white-hot tornado on the surface.

Stone Age Toolkit
Would you know how to use an ancient stone tool if you unearthed one? Try your hand here.

Before Clovis
Were people in North America long before the so-called "first Americans"? Explore an interactive map.