Some 12,800 years ago, a site found in modern-day Syria was home to one of the first known human settlements, a momentous place where nomadic people first started to settle down and began cultivating crops. As it turns out, the settlement also bears evidence of another huge moment in Earth’s history: a cosmic impact.
Archaeologists from the University of California, Santa Barbara, have found evidence of a cosmic impact by looking at objects found at the ancient Abu Hureyra archaeological site in northern Syria. The site now lays under lake Asaad after it was flooded in 1974 when the Tabqa Dam was closed. However, many of the artifacts collected here during the early 1970s reveal a deeply mysterious story.
The evidence comes in the form of unusual blobs of glass that have been splashed on many of the site's artifacts, including building material and animal bones. To create such material on Earth, temperatures must be upwards of 2,200°C (3,992°F), indicating the settlement was struck by a super-hot, high-energy asteroid impact around 12,800 years ago.
"To help with perspective, such high temperatures would completely melt an automobile in less than a minute," James Kennett, study author and emeritus professor of geology at UC Santa Barbara, said in a statement.
Reporting their findings in the Nature journal Scientific Reports, an analysis of the melt glass revealed it included minerals rich in chromium, iron, nickel, sulfides, titanium, and even platinum- and iridium-rich melted iron, which Kennett said “are commonly found during impact events.” The town would have been obliterated in a few moments, sparking instant death for its inhabitants. However, it looks like this tragedy is part of a much larger story.
The dating of 12,800 years ago is significant. This is a time that neatly matches up with the Younger Dryas impact hypothesis, a controversial theory that North America, South America, Europe, and western Asia were struck by catastrophic flecks of a disintegrating asteroid or a comet strike about 12,800 years ago
Some scientists suspect this event might have happened in some form or another due to the presence of strange high-temperature materials, such as melt glass and nanodiamonds, found in the rock layers across the world from 12,800 years ago, known as the Younger Dryas Boundary (YDB) strewnfield. The time also pairs up with mass animal extinctions and a brief dip in temperatures, perhaps the result of an “impact winter”.
Judging by the unusual nature of the melt glass found in Abu Hureyra, the researchers believe it was extremely close to one of the fragmented comet impacts.
“A single major asteroid impact would not have caused such widely scattered materials like those discovered at Abu Hureyra,” said Kennett. “The largest cometary debris clusters are proposed to be capable of causing thousands of airbursts within a span of minutes across one entire hemisphere of Earth. The YDB hypothesis proposed this mechanism to account for the widely dispersed coeval materials across more than 14,000 kilometers of the Northern and Southern Hemispheres,” he added.
“Our Abu Hureyra discoveries strongly support a major impact event from such a fragmented comet.”