The killer asteroid is believed to have struck northern Greenland during a period of Earth’s history known as the Younger Dryas. The cataclysmic collision triggered a global cooling of the climate that was felt in North America, South America and Europe. Researchers in South Africa believe the cataclysm contributed to a mass extinction of species at the end of the last ice age – the Pleistocene Epoch. A terrifying take away from the discovery is another such impact could happen in the future, regardless of how low the probability seems right now.
The discovery was published in the journal Palaeontologia Africana.
Professor Francis Thackeray, an anthropologist from the University of the Witwatersrand, Johannesburg, believes the discovery supports the Younger Dryas extinction theory.
He said: “Our finding at least partially supports the highly controversial Younger Dryas Impact Hypothesis.
“We seriously need to explore the view that an asteroid impact somewhere on Earth may have caused climate change on a global scale, and contributed to some extent to the process of extinctions of large animals at the end of the Pleistocene, after the last ice age.”
Professor Thackeray led a team of researchers at a dig Limpopo Province, north of Pretoria in South Africa.
An asteroid impact somewhere on Earth may have caused climate change
Francis Thackeray, University of the Witwatersrand
The researchers found a “platinum spike” in geological samples dating back 12,800 years.
The samples were linked to a large meteor, which Professor Thackeray said are rich in the precious metal.
Archaeologists believe the asteroid may have also indirectly impacted human settlements across the plains of Africa.
Researchers have discovered the so-called Robberg stone artefact industry came to an abrupt end in parts of the country at the time of the impact.
Professor Thackeray said: “Without necessarily arguing for a single causal factor on a global scale, we cautiously hint at the possibility that these technological changes, in North America and on the African subcontinent at about the same time, might have been associated indirectly with an asteroid impact with major global consequences.
“We cannot be certain, but a cosmic impact could have affected humans as a result of local changes in environment and the availability of food resources, associated with sudden climate change.”
The researchers have also found evidence of climate change 12,800 years ago at the Wonderkrater spring mound in South Africa.
Pollen samples doing back to the Younger Dryas suggest temperatures plummeted in the Northern Hemisphere.
The cooling could have been the result of platinum-rich dust from the asteroid spreading through the atmosphere.
Professor Thackeray said the most likely point of impact is a 19-mile-wide (31km) crater in Greenland, beneath the Hiawatha Glacier.
He said: “There is some evidence to support the view that it might possibly have been the very place where a large meteorite struck the planet Earth 12,800 years ago.
“If this was indeed the case, there must have been global consequences.”
The anthropologist added: “Our evidence is entirely consistent with the Younger Dryas Impact Hypothesis.”
Unfortunately, there are asteroids flying around the solar system at this very moment that threaten to strike the Earth again.
One of these rocky bodies is the “Potentially Hazardous Asteroid” Apophis 99942.
The space rock measures about 1,115ft (340m) and is expected to come exceptionally close to Earth in just 10 years.
Professor Thackeray said: “The closest encounter will take place precisely on Friday, April 13, 2029.
“The probability of the Apophis 99942 asteroid hitting us then is only one in 100,000, but the probability of an impact may be even higher at some time in the future, as it comes close to Earth every 10 years.”
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