Previous studies have been slowly piecing together what happened after the so-called Chicxulub impact using a combination of computer models and the geologic fallout found at a smattering of sites around the world.
“It’s not a matter of whether there will be big impacts,” he says, “it’s just a matter of when.” Drilling into disaster Studying these events helps us more strongly grasp the vulnerabilities of life on Earth, he says. While it’s unlikely another asteroid smashup of this magnitude will happen in our lifetimes, significant impacts are inevitable in the larger arc of our planet’s evolution, says Purdue University’s Jay Melosh, who is not part of the study team but who worked on other sections of the crater core. Find out the origins of our home planet and some of the key ingredients that help make this blue speck in space a unique global ecosystem. “The level of detail kind of blows you away.”Įarth is the only planet known to maintain life.
“They can put their fingers on moments in that event,” says Jennifer Anderson, an experimental geologist who studies impact cratering at Winona State University. As they report today in the Proceedings of the National Academy of Sciences, the dark layers reveal stunning details, including the sheer amount of material that piled up mere hours after the strike, along with bits of charcoal later left by raging wildfires. Now, by subjecting the rocky core to a battery of tests, including geochemical study and x-ray imaging, the research team has assembled a meticulous timeline chronicling events on that fateful day-sometimes down to the minute. The impact triggered a nightmarish sequence of events that sent some 75 percent of plant and animal species spiraling to extinction- including all the nonavian dinosaurs. This change in the rock marks one of the most catastrophic events in Earth’s history, some 66 million years ago, when an epic asteroid slammed into the sea just offshore of Mexico’s Yucatán Peninsula.
“It was nothing like the stuff above,” recalls Sean Gulick, a co-chief scientist of the expedition and a researcher at the University of Texas at Austin. But then a stark divide appeared as the layers abruptly darkened. Inch by inch, the team pulled up the skinny core of ghostly white limestone from the ocean floor, gazing at the compressed remains of ancient organisms that died tens of millions of years ago.
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