The Dinosaur Asteroid

Where did the asteroid that killed the dinosaurs come from? That’s what our listener Lucian wants to know. We’ll watch a “podcast movie” about the fateful impact, starting with an explosive collision in space that sent asteroids careening towards Earth. Then we’ll discover the science behind the story, with the help of planetary scientist Sean Gulick. He led an expedition to drill into the impact crater - and find the final piece of evidence in the asteroid theory. This episode is sure to blow your mind.


Sean Gulick

Sean Gulick is a geologist and research professor at Jackson School of Geosciences part of The University of Texas at Austin. He studies how the outermost layer of earth changes because of extreme events, and what this means about our past, present, and possibly future.

Sean is a big advocate for science and discovery. He encourages everyone to push themselves to learn new things.

Want to hear more from Sean? Check out his TEDx Talk “The Importance of Discovery.”


Core samples are a vital tool for geologists. To learn more about them, revisit our episode on scientific drilling.


Between Jupiter and Mars there is a ring of large irregular space rocks, called the asteroid belt. Scientists believe these asteroids are leftovers from the formation of our solar system. They range in size from hundreds of miles across to several feet wide.

Many scientists have tried to solve the case of what killed the dinosaurs, looking to the asteroid belt for clues. One popular theory came out in 2007, William Bottke from the Southwest Research Institute hypothesized two large asteroids collided breaking into several pieces. Parts of the broken asteroid spun into space and eventually struck the moon and Earth. This impact they thought could have killed the dinosaurs.

Dinosaur-Killing Asteroid Traced to Breakup Event - NPR

However, in 2011 NASA disproved this theory saying after such a collision there wouldn’t have been enough time for the fragments to reach Earth at the time the dinosaurs died. The case remained cold.

In 2021, Another strong theory emerged. The asteroid could have come from the outer part of the asteroid belt, not a collision. Using computers to simulate hundreds of millions of years, David Nesvorný, another researcher from the Southwest Research Institute, led a study that found asteroids over 6 miles wide could be flung from the outerbelt and set on a collision course with Earth once every 250 million years. This timing would be consistent with the Chicxulub crater formation.

Origin of dinosaur-ending asteroid possibly found. And it's dark. - Live Science

Finding the source of the impactor that wiped out the dinosaurs -

The debate is still ongoing.


Top 10 weirdest extinction ideas - Smithsonian Magazine

Putting the volcano theory to rest - New York Times


What do you think the planet would look like if the asteroid didn’t hit Earth 66 million years ago?

Talk about it with your family and friends, or try writing a story about it. What kinds of new dinosaurs might have evolved? And would people be around to see them?

Share your speculative fiction story with us at We’d love to read them!