For years researchers have speculated that it was a comet that changed the earth’s climate enough to bring an end to the Clovis culture that thrived in North America some 13,000 years ago.
Evidence of a comet wiping out the Clovis was documented by Allen West, from GeoScience Consulting and Albert Goodyear III, a professor at the University of South Carolina in the South Carolina Institute of Archaeology and Anthropology, in a study published in the October 2007 issue of the Proceedings of the National Academy of Science.
West explained to LiveScience in 2009 that human overhunting and climate change were not sufficient to cause the major collapse of the Clovis civilization, but with the addition of the comet impact, the “perfect storm” was created.
“There’s no way to tell what percentage each one of those three things played in the demise of the megafauna,” West said at the time. “But almost certainly all three were involved—impact, climate change and humans.”
In a new study, first available in January from the American Geophysical Union monograph, researchers say that no appropriately sized craters from the time period have been found.
“There’s no plausible mechanism to get airbursts over an entire continent,” Mark Boslough, a physicist with Sandia National Laboratories in Albuquerque, New Mexico and lead author of the study, said in a press release. “For this and other reasons, we conclude that the impact hypothesis is, unfortunately, bogus.”
Researchers from Royal Holloway University of London and 13 other academic institutions also say that proposed fragmentation and explosion mechanisms “do not conserve energy or momentum,” a basic law of physics that has to be satisfied for the impact-caused climate change theory to bear weight.
“The theory has reached zombie status,” said Professor Andrew Scott from the Department of Earth Sciences at Royal Holloway in a press release. “Whenever we are able to show flaws and think it is dead, it reappears with new, equally unsatisfactory, arguments.
“Hopefully new versions of the theory will be more carefully examined before they are published.”
The Clovis culture was named by archaeologists after the town in New Mexico where stone tools were found in the 1920s and 30s.