The asteroid that hit Earth and caused the Cretaceous-Paleogene extinction event is one of the most famous impacts in history. It changed life on our planet forever. But did you know scientists aren’t even sure how big it was?
That’s right: The answer to the question that scientists have been looking for years was, “How massive was the asteroid that killed the dinosaurs?” We do know it was heavy enough to cause this massive extinction event, but no one knows for sure.
The Chicxulub Asteroid
The asteroid was between 10 and 15 kilometers wide, with a crater diameter of about 150 kilometers. That’s about the size of Rhode Island or a small city. It was also cumbersome, estimated to be 10 billion tons—more than 1,000 times the mass of Mount Everest.
The angle of impact is essential for calculating the speed of the asteroid. An angle of 45 degrees indicates that the impactor struck Earth at a relatively low speed, which means it was not an extremely large object. A higher angle would have meant it traveled faster when it hit Earth, which would have been necessary for producing such a large crater as Chicxulub Crater.
That’s not just big. It’s massive: if you tried to land it on top of Mount Everest, it would bury the mountain under more than 1.6 kilometers of rock. The impact was so significant that scientists believe it triggered tsunamis and earthquakes worldwide. One earthquake may have even caused a landslide in Washington state that created what is now known as “the Channeled Scablands.”
The fact that this event occurred 66 million years ago makes figuring out how giant the asteroid was much harder—it’s difficult for us here in 2022 to know exactly how much Earth changed after such an impact. The asteroid impact, along with erupting volcanoes and climate change, caused 75% of life to disappear. But there’re clues we can look at when trying to figure out how large you needed an object for such devastation.”
The Cretaceous-Paleogene Extinction Event
Scientists disagree on whether the asteroid was a stony meteorite or an icy comet. Scientists haven’t reached a consensus on this question. Scientists disagree about the mass of the asteroid that killed the dinosaurs because there’re several different theories about what killed off dinosaurs and other animals. Each theory answers how heavy an asteroid would need to be.
The crater created by the impact is about 15 kilometers across. It’s not visible from space, though. That’s because it’s been covered in sediment and rock for millions of years, which makes it difficult to see from a spacecraft or even from low Earth orbit with a high-powered telescope.
The Aftermath of This Heavy Asteroid
The asteroid slammed into the Earth at Chicxulub, Mexico, about 65 million years ago. The impact caused an explosion that released more than 100,000 times as much energy as the atomic bomb dropped on Hiroshima, Japan. The asteroid hurled a massive cloud of superheated dust and gas into the atmosphere.
The dust spread around the globe within a few months and blanketed Earth in darkness for several days. Sunlight couldn’t reach Earth’s surface, and temperatures plunged tens of degrees. Plants died, and food sources ran low for most animals, including plant-eating dinosaurs. They had no way to adapt or survive in this new environment and gradually died off, allowing other species to take their place.
What’s fascinating about the extinction of the dinosaurs is that it’s still a mystery. The scientists who study it are still learning new things about this catastrophic event – and there will always be more to learn.