Scientists Reconstruct Massive Asteroid that Collided With Earth 3.26 Billion Years Ago

Posted on April 9, 2014

Scientists have reconstructed an asteroid that hit Earth 3.26 billion years ago. The graphic above compares it to the to the size of the asteroid thought to have killed the dinosaurs 65 million years ago. The ancient asteroid dwarfs both the dinosaur killer and Mount Everest. The scientists say the ancient asteroid was at leat 37 kilometers (23 miles) wide. They estimate it punched a crater 500 kilometers (300 miles) wide in the Earth's crust. The impact jolt would have been bigger than a 10.8 magnitude earthquake. It would have sent seismic waves hundreds of kilometers through the Earth, which would have caused additional earthquakes. Tsunamis thousands of meters deep would have swept across the oceans.

The scientists say the sky would have become red hot and oceans would have boiled after the impact with the monster asteroid 3.26 billion years ago. Theysay it "sent vaporized rock into the atmosphere, which encircled the globe and condensed into liquid droplets before solidifying and falling to the surface." The researchers also believe the impact "disrupted the Earth's crust and the tectonic regime that characterized the early planet, leading to the start of a more modern plate tectonic system."

Donald Lowe, a geologist at Stanford University and a co-author of the study, says of the asteroid, "We knew it was big, but we didn't know how big."

The scientists think the asteroid hit the Earth thousands of kilometers away from the Barberton Greenstone Belt, although they can't pinpoint the exact location.

The research has been accepted for publication in Geochemistry, Geophysics, Geosystems, a journal of the American Geophysical Union.



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