Friday, January 2, 2009
Tiny diamonds found in the soil are strong evidence a comet exploded on or above North America nearly 13,000 years ago, leading to the extinction of dozens of mammal species.
Science suggests the cataclysm also reduced the population of the earliest people to inhabit the region and triggered a 1,300-year-long cold spell that stretched around the world.
The heat generated by the extraterrestrial impact likely melted much of a glacier that once covered the Great Lakes region, sending a massive flood down the Mississippi River.
According to the report, the cold waves of glacial runoff into the Gulf of Mexico shifted Atlantic Ocean currents, changing climate patterns throughout the world. This was in a cooling period known as the Younger Dryas.
A rare swarm of comets rained over North America about 12,900 years ago, sparking fires that produced choking, leading to the extinction of a large range of animals, including mammoths.
[The scientific study that lead to these conclusions was conducted by a group of eight archaeologists and geologists from the universities of Oregon and California, Northern Arizona University, Oklahoma University and DePaul University. Their findings were published at the end of 2008 in the journal Nature.]