A recent discovery has led scientists to say we need to reassess the asteroid threat to Earth, which “can be completely devastating over a large area.”
Research by a Kent-based space scientist has found new evidence that meteor particles hit the Antarctic ice sheet 430,000 years ago.
Other scientists and geologists believe that comet or asteroid attacks about 12,900 years ago could have triggered a mini ice age that lasted 1,200 years and caused mass extinctions.
The new findings underscore the importance of reassessing the threat posed by medium-sized asteroids with the potential for “devastating” consequences, the Kent team said.
The researchers found alien particles on the summit of Walnumfjellet in the Sor Rondane Mountains in East Antarctica.
The discovery indicated a so-called meteoritic touchdown event at low altitude, in which a jet of molten and vaporized material from an asteroid at least 100 meters in size reached the surface at high speed.
The impact covered a circular area of around 2,000 km – an “almost continental distribution,” said Dr. Matthias van Ginneken from the School of Physical Sciences at the University of Kent.
The study, published in the Science Advances Journal, found that finding evidence for such events “continues to be important in understanding Earth’s history of exposure and assessing the dangerous effects of asteroid impacts.”
Dr. van Ginneke said that while it is “highly unlikely” that such an event would take place in a densely populated area – with less than 1% of the earth’s surface being densely populated – its effects can be widespread.
He said, “For hundreds of kilometers, severe effects from such an impact can be felt.
“Even if such an impact were to occur hundreds of kilometers from a densely populated area, the extent of the devastation would not be negligible and should be considered.”
Dr. van Ginneken said the study could help improve knowledge about the frequency of such effects in the past, and thus how often they could occur in the future.
The paper states: “These events are potentially completely destructive over a large area, corresponding to the area of interaction between the hot jet and the ground.
“Touchdown events must not endanger human activity, apart from the formation of a large cloud and the injection of ice crystals and impact dust into the upper atmosphere when these occur over Antarctica.
“However, if a touchdown event occurs over a densely populated area, it would result in millions of casualties and serious damage over distances of up to hundreds of kilometers.”
A growing number of scientists and geologists believe that comet or asteroid attacks could have triggered a mini ice age that lasted 1,200 years and began about 12,900 years ago.
The Younger Dryas Impact Hypothesis, also known as the Clovis Comet Hypothesis, assumes that fragments of a large disintegrating asteroid or comet struck North America, South America, Europe, and western Asia. It is said that this triggered a climate disaster and catastrophic flooding that wiped out many species of megafauna, including camels and mammoths, as well as the people of the Clovis culture in North America.
Alternative historians posit that the alien effects wiped out an advanced civilization whose survivors “restarted” civilization in places like Gobekli Tepe, Turkey – a megalithic complex with numerous giant stone circles that are at least 6,000 years older than Stonehenge.
Gobekli Tepe is believed to be the place where people turned away from a hunter-gatherer lifestyle and began learning agricultural techniques more than 11,000 years ago.