It sounds like a story out of a science fiction movie: A comet streaking across the planet creates smoke and soot, blocking out the sun. Climate change followed, which wiped out early man in North and South America and animals from mammoths to mastodons.
A UC Santa Barbara researcher said they have new evidence to back the theory that it happened.
"The Younger Dryas Impact Hypothesis argues that there was a major cosmic impact by a comet that shook the earth some 12,800 years ago," said UCSB researcher and Professor Emeritus of Earth Science James Kennett.
He talked about what they think the comet did as its tail streaked across North America.
"This comet caused the Earth to experience very high temperatures. The consequences were pretty profound. It was the primary reason for the extinction of the large megafauna, the big animals that occurred in North and South America," said Kennett. "Those include the mammoth, the mastodon, and the sabre-tooth cat."
The researcher added that it was also responsible for the extinction of some humans.
"The so-called Clovis culture, a stone-age culture, just disappeared suddenly at the same time as all these big animals," said Kennett.
Kennett and other researchers said they have new evidence, in the form of grains of sand, to back the theory. The team collected samples from three archaeological sites in America: one in New Mexico, one in Arizona, and one in our region, Arlington Canyon, on Santa Rosa Island in the Channel Islands.
Kennett discussed the details of the research that led to the discovery of new evidence of cosmic impacts on Earth.
"We have now discovered shocked quartz grains...evidence for this cosmic impact," he explained. "Image sand grains exposed to very high temperatures and very high pressure. The grains crack. They fracture. And then the high temperatures melt [the] surrounding silica and inject the silica into the fractured quartz grains. It commonly occurs during cosmic impact events."
Evidence shows there was no Big Bang where everything changed instantly from a massive impact. The changes happened over time, with smoke and soot blocking the sun.
Kennett said technological improvements over the last two decades have helped make the advanced research possible.
An interesting sidebar in the research is that scientists believe the cosmic event nearly 13,000 years ago wiped out North America’s horse population. The horses survived in Eurasia.
Kennet said they were reintroduced to North America and to Native Americans by explorers coming to the continent hundreds of years ago.
