Drilling to Doomsday

Mark Garlick/Discover magazine

Mark Garlick/Discover magazine

For billions of years, it waited.

A city-sized chunk of primordial space rock circled the solar system somewhere between the orbits of Mars and Jupiter. Earth took shape. Life evolved. And all the while, the space rock just drifted, tumbling end over end like a poorly thrown football.

Then, some unknown celestial mechanics shoved this 9-mile-wide projectile out of its orbit. Destination: Earth.

The asteroid belt escapee arrived 66 million years ago. In those last dinosaur days, any skygazing T. rex might have tilted its head in curiosity as a strange, new star grew dozens of times brighter than the sun. Burning through the atmosphere at 45,000 mph, the asteroid’s leading edge hit the Gulf of Mexico while its other end was still higher than a cruising 747.

It excavated a hole nearly 20 miles deep, ripping fault lines down to Earth’s mantle. For two minutes, land behaved like liquid. The open hole left behind by the asteroid quickly filled back in as material rebounded from the depths, building a great ring of peaks around the crater’s center.

Read the full story in Discover magazine.