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JANUARY 13, 2020 BY EVAN GOUGH
Almost 800,000 Years Ago, an Enormous Meteorite Struck Earth. Now We Know Where.
20% of the surface of Earth’s Eastern Hemisphere is littered with a certain kind of rock. Black, glossy blobs called tektites are spread throughout Australasia. Scientists know they’re from a meteorite strike, but they’ve never been able to locate the crater where it struck Earth.
Now a team of scientists seems to have found it.
The chunk of rock that crashed into Earth about 790,000 years ago, during the Early Pleosticine. It was about 2 km (1.2 miles) wide. Its impact on Earth was enormously powerful, spreading debris across Asia, Australia, and even Antarctica.
The evidence for this strike is in the form of the tektites. They’re pieces of Earthly material, super-heated and melted by the impact, then thrown into the atmosphere. Tektites are mostly centimeter sized blobs of green or black glass, though some are larger. In scientific terms, they’re “quenched molten ejecta.” They fell to the ground over a wide area throughout what’s known as the Australasia strewnfield.
Now a team of researchers say they’ve found the exact location of the strike. The impact crater lies under a feature called the Bolaven Plateau volcanic field in Laos.
There are four other strewnfields of tektites on Earth, and scientists have found the craters responsible for each of them. But the impact responsible for the Australasian strewn field has been difficult to find. Scientists have spent a century trying. So vexing was the search for a crater large enough to create the tektite field that some scientists proposed multiple smaller impacts to explain it.
In the new paper, a team of researchers say they have four separate lines of evidence showing that the impact crater lies under the Bolaven Plateau volcanic field. The paper is titled “Australasian impact crater buried under the Bolaven volcanic field, Southern Laos.” The paper is published in Proceedings of the National Academy of Sciences of the United States of America.
– more–
https://www.universetoday.com/144568/almost-800000-years-ago-an-enormous-meteorite-struck-earth-now-we-know-where/