October 23, 2009
A comet impact didn't set off a 1,300-year cold snap that wiped out most life in North America about 12,900 years ago, scientists say.
Though no one disputes the occurrence of the frigid period, known as the Younger Dryas, more and more researchers have been unable to confirm a 2007
finding that says a collision triggered the change.
The earlier study says the drop in temperature, plus fires from the purported impact, wiped out sabertooths, mastodons, and other giant animals, and
may have caused the decline of an early civilization known as the Clovis culture.
The 2007 research was based on a combination of archaeological artifacts and extraterrestrial magnetic grains in soil samples found in a thin layer of
sediment throughout North America.
North America's Great Lakes (pictured in an aerial shot on May 4, 2002) were created during glacial retreats and advances over millions of
years—including the brief cold snap called the Younger Dryas, which occurred about 12,900 years ago.
What caused the cold snap, though, has proved controversial: Recent research has weakened a theory that a giant comet caused the drop in temperatures
and wiped out much of North America's wildlife, scientists said in October 2009.
Comet Wiped Out Early North American Culture, Animals, Study SaysJohn Roach
for National Geographic News
May 23, 2007
A comet exploded over North America about 13,000 years ago, causing a long bout of climate cooling, according to a controversial new theory presented
The extraterrestrial impact may help explain massive mammal die-offs and the demise of one of the earliest American cultures.
Comet Hale-Bopp as seen as it passed over Mexico in 1997. A new study suggests that the impact of a comet some 13,000 years ago may have caused the
extinction of ancient mammals and brought about the demise of one of North America's earliest cultures.
Interesting correlation, I honestly don't think they know exactly what happened but you can always speculate.