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Australia's Yarrabubba impact crater is the oldest in the world, scientists confirm

Daily Mail - Science & tech

Earth's oldest asteroid strike was at Yarrabubba, in Western Australia's outback, around 2.229 billion years ago, Aussie scientists have confirmed. The team from Curtin University in Perth used isotopic analysis of minerals to calculate the precise age of the 43-mile-wide impact crater for the first time. The asteroid strike that created the crater occurred 200 million years before the next oldest impact at Vredefort in South Africa. The Yarrabubba impact structure is regarded as one of Earth's oldest, but until now lacked a precise age. 'Yarrabubba, which sits between Sandstone and Meekatharra in central WA, had been recognised as an impact structure for many years, but its age wasn't well determined,' said Professor Chris Kirkland at Curtin University.


2.229 billion years: Scientists date world's oldest meteor crater, say it may have triggered warming

The Japan Times

TOKYO – A crater in western Australia was formed by a meteor strike more than 2.2 billion years ago and is the world's oldest known impact site, new research published Wednesday shows. The study marks the first time that the Yarrabubba crater has been precisely dated, at 2.229 billion years old, and means it is 200 million years older than any similar site known on Earth. The revelation also raises the intriguing possibility that the massive impact could have significantly altered the Earth's climate, helping end a period of global "deep freeze. Scientists had long suspected that Yarrabubba, in a remote part of the outback, dated back several billion years. But dating ancient craters is not easy: the sites tend to be poorly preserved because erosion and tectonic events such as earthquakes have "progressively erased into the geologic past," the researchers wrote in their paper, published in the journal Nature Communications on Wednesday. And even where craters are still present, determining their age is complex. To date Yarrabubba precisely, the team hunted for evidence of "shock recrystallization" in minerals at the site -- essentially where the massive impact of the meteor had altered the structure of materials including zircon and monazite. But finding that record in the minerals involved searching for microscopic grains, using a high-tech scanning process known as Sensitive High Resolution Ion Micro Probe, or SHRIMP dating. Once identified, uranium in the grains helped the scientists determine a precise date, which they found coincided with a period when the planet emerged from a global deep freeze known as "Snowball Earth.


Earth was hit by massive asteroid more than 3 billion years ago that could have wiped out humanity

Daily Mail - Science & tech

Scientists have found evidence of a massive asteroid, 12 to 19 miles (20 to 30km) wide, that struck Earth more than 3 billion years ago. The asteroid would have hit with an impact larger than anything humans have experienced. The discovery was made in tiny glass beads called spherules, found in north-western Australia, which were formed from vaporised material from the asteroid impact. The asteroid is the second oldest known to have hit the Earth and one of the largest. 'It would have caused huge tsunamis and would have made cliffs crumble, scientists say.


Evidence of enormous asteroid unearthed in Australia

Christian Science Monitor | Science

Scientists have unearthed evidence of one of the largest asteroids ever to assail the Earth. Delving into some of the oldest known sediments on the planet, researchers in northwestern Australia discovered a trove of tiny glass beads known as spherules, vaporized remnants of an asteroid slamming into the surface. The research, to be published July 2016 in the journal Precambrian Research, details an impact more powerful than any yet experienced by mankind. "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," said lead author Andrew Glikson from The Australian National University (ANU). The location of the crash site is hard to discern, as material from the asteroid would have spread to every corner of the globe.


Evidence of huge asteroid unearthed in Australia

Christian Science Monitor | Science

Scientists have unearthed evidence of one of the largest asteroids ever to assail the Earth. Delving into some of the oldest known sediments on the planet, researchers in northwestern Australia discovered a trove of tiny glass beads known as spherules, vaporized remnants of an asteroid slamming into the surface. The research, to be published July 2016 in the journal Precambrian Research, details an impact more powerful than any yet experienced by mankind. "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," said lead author Andrew Glikson from The Australian National University (ANU). The location of the crash site is hard to discern, as material from the asteroid would have spread to every corner of the globe.