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Post by rugbytoffee on May 17, 2016 18:25:48 GMT
Scientists believe they have found evidence of a giant asteroid that smashed into the Earth almost four billion years ago.
Tiny glass beads, called spherules, have been found in the country's remote north-west and were formed by vaporised material from an asteroid impact, say researchers from the Australian National University (ANU).
Dr Andrew Glikson from the ANU's Planetary Institute said it was likely the asteroid was up to 30km (18.6 miles) wide, and would have left a crater hundreds of miles across.
He said: "The impact would have triggered earthquakes orders of magnitude greater than terrestrial earthquakes.
"It would have caused huge tsunamis and would have made cliffs crumble.
"Material from the impact would have spread worldwide."
He says it is not clear exactly where the asteroid hit the earth, adding that volcanic activity and tectonic movements mean the crater has long gone.
Dr Glikson, along with Dr Arthur Hickman from Geological Survey of Western Australia, found the glass beads in a drill core in some of the oldest known sediments on Earth.
The sediment layer was originally part of the sea floor, but has been preserved between two volcanic layers.
Testing of the glass beads found platinum, nickel and chromium in levels which match those in asteroids.
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Post by evertonfan1968 on May 17, 2016 18:52:26 GMT
How can they presume it was 30km across from small fragments?
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Post by rugbytoffee on May 17, 2016 18:54:46 GMT
How can they presume it was 30km across from small fragments?  But they are the supposed experts |
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Post by evertonfan1968 on May 17, 2016 19:00:33 GMT
How can they presume it was 30km across from small fragments? But they are the supposed experts Yeah but a crater hundreds of miles across too. Surely they'd see it with the technology they have today. There must have been loads that hit the earth over the years. |
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