Around 66 million years ago, all non-avian dinosaurs went extinct. Was the culprit a 6-mile wide asteroid that collided with Earth? Or did other factors contribute to the dinosaurs’ die-off? Paleontologist Aki Watanabe looks at other theories for why dinosaur populations declined during this famous mass extinction.
Next, watch Space Rocks: Comets, asteroids, meteors, & meteorites.
But since humans weren’t around at the end of the Cretaceous period, how do we know an asteroid hit Earth? “Astrophysicist Jackie Faherty reveals how clues found in sedimentary rock and on the ocean floor have helped scientists piece together this millennia-old mystery.”