A miles-wide asteroid struck the earth 66 million years ago and led to the extinction of the dinosaurs and countless other species. The impact left behind the 90-mile-wide Chicxulub crater buried miles beneath the Yucatán Peninsula and the Gulf of Mexico. In 2016, a core sample hundreds of feet long was extracted from the peak inner ring of the crater. A team of scientists led by University of Texas at Austin geologist Sean Gulick spent years analyzing the sample to tell the story of what happened on the day of the impact, which ended the Cretaceous and began the Cenozoic period.
Within minutes of the asteroid strike, Gulick and colleagues found, the underlying rock at the site collapsed and formed a crater with a peak ring. The ring was soon covered by over 70 feet of additional rock that had melted in the heat of the blast.
The sea battered against the new hole in the planet, and in the minutes and hours that followed, surges of water rushing back into the crater carried laid down more than 260 additional feet of melted stone atop the already accumulated rock. Then a tsunami hit. The wave, reflected back toward the crater after the initial impact, added another distinct layer of rock—sediments of gravel, sand and charcoal—all within the first 24 hours of the strike.
The planetary collision triggered wildfires inland, burning forests that were later doused by devastating waves. Debris from the charred woods washed out to sea, and some accumulated in the crater.
That was just the beginning. Read how the impact's effects changed the entire world at Smithsonian.