Everyone knows that a giant asteroid killed (most of) the dinosaurs. And this 1980 Chevy Malibu is proof that it wasn’t the last chunk of rock to crash down to the surface of the planet. Now, a new discovery suggests that a meteorite impact has been hiding practically in plain sight since the end of the last geological era. And it’s friggin’ huge.
Right Before Our Very Ice
If you’ve ever flown a small plane over the northern edge of Greenland — we’re not saying you have, we’re saying if — you might have noticed a strange, nearly perfect circle of smooth ice atop one of the glaciers creeping slowly toward the Arctic ocean. Or you might not have. It’s actually pretty difficult to see from an airplane — considerably harder than a polar bear in a blizzard. But when researchers took a look at satellite imaging of the area that was gathered when the sun was low in the sky, the large, smooth section stood out against the hilly regions all around it.
This smooth section is on a chunk of ice known as Hiawatha glacier, and the team led by Brendan Lynch from the University of Kansas went looking at the satellite images because they’d already spotted something odd from radar images of the area. The circle, which measures 19.26 miles (31 kilometers), is hiding a massive depression in the ground. Kurt Kjær and his team from the University of Copenhagen returned to the area to map the tectonic plates and collect sediments in the area. When they examined the quartz sand, they found the type of deformation you’d find if there had been a massive impact some time ago. That was all the evidence the researchers needed: This depression was created by a meteorite — likely about 1 kilometer (0.62 miles) across and made of iron, based on the size of the crater and minerals found in the area.
A Record Writ in Stone
Although they haven’t quite been able to date the crater yet, researchers place it somewhere between 12,000 and three million years old. This isn’t the first time that scientists have suspected a massive meteor strike sometime in the range of 12,000 years ago. After all, that was about the time that the megafauna of the Americas suddenly went extinct.
In 2007, researchers dug deep into the question of what killed the mammoths, sabertooth cats, and other giant mammals — literally. Underground, there was a strata of spherules — hardened droplets of once-molten rock — mixed into clay that some people theorized were cosmic in origin. Unfortunately, earth scientists weren’t very convinced. The most damning piece of evidence they offered? Many of those “spherules” turned out to be fungal spores and not the alien kind you’d find in a comic book. But even if the mammoth-killing impact theory is bunk, this new discovery suggests that a massive meteorite could have hit the planet around the same timeframe.