An elegant archaeological theory, under fire for results that cant be replicated, may ultimately come undone. Now, four years after the purportedly supportive evidence was reported, a host of scientific authorities systematically have made the case that the comet theory is "bogus." Researchers from multiple scientific fields are calling the theory one of the most misguided ideas in the history of modern archaeology, which begs for an independent review so an accurate record is reflected in the literature. Read more
UA Archaeologist, Colleagues Find No Evidence of Catastrophic Impact
Anthropology professor Vance T. Holliday and others take issue with claims that a comet strike led to the demise of Paleoindian megafauna hunters during the Pleistocene. The notion of an object such as a comet or asteroid striking the Earth and wiping out entire species is compelling, and sometimes there's good evidence for it. Most scientists now agree that a very large object from space crashed into what is now the Yucatan Peninsula in Mexico 65 million years ago, altering climate patterns sufficiently to end the age of the dinosaurs. Read more
Tiny black spheres previously seen as evidence that a catastrophic asteroid impact caused a little ice age are actually charred fungus, according to new research. Ideas about the origins of the Younger Dryas stadial, a cold period which began around 12,900 years ago, may need to be revised. Read more
Fossil evidence casts doubt on Younger Dryas impact theory
New findings challenge a theory that a meteor explosion or impact thousands of years ago caused catastrophic fires over much of North America and Europe and triggered an abrupt global cooling period, called the Younger Dryas. Whereas proponents of the theory have offered "carbonaceous spherules" and nanodiamonds - both of which they claimed were formed by intense heat - as evidence of the impact, a new study concludes that those supposed clues are nothing more than fossilised balls of fungus, charcoal, and fecal pellets. Moreover, these naturally-occurring organic materials, some of which had likely been subjected to normal cycles of wildfires, date from a period of thousands of years both before and after the time that the Younger Dryas period began - further suggesting that there was no sudden impact event. Read more
A British astronomer has published new evidence that North America was strafed by thousands of fragments from a massive comet about 12,900 years ago, a theory he says is the best explanation yet for why the planet was plunged into a 1,000-year cooling period and dozens of Ice Age mammals went extinct at that time. Read more
Comet caused global cooling and extinctions 13000 years ago
A shower of fragments from a disintegrating comet may have led to a dramatic global cooling 13 000 years ago, according to astronomer Professor Bill Napier of the Cardiff University Astrobiology Centre. He presents his new model in the journal Monthly Notices of the Royal Astronomical Society. 13 000 years ago the Earth suddenly cooled by as much as 8°C, interrupting the warming which was occurring at the end of the last ice age and causing glaciers to readvance. Evidence has recently been found that these catastrophic changes were initiated by some extraordinary extraterrestrial event. The boundary is marked by the occurrence of a "black mat" layer a few centimetres thick found at many sites throughout the United States containing high levels of soot indicative of continental-scale wildfires, as well as microscopic hexagonal diamonds (nanodiamonds) which are produced by shocks and are only found in meteorites or impact craters. Read more
Absence of evidence for a meteorite impact event 13,000 years ago
An international team of scientists led by researchers at the University of Hawaii at Mnoa have found no evidence supporting an extraterrestrial impact event at the onset of the Younger Dryas ~13,000 years ago. Read more
Around 12,800 years ago the northern hemisphere was hit by a mini ice-age, known by scientists as the Younger Dryas, and nicknamed the 'Big Freeze', which lasted around 1300 years. Geological evidence shows that the Big Freeze was brought about by a sudden influx of freshwater, when the glacial Lake Agassiz in North America burst its banks and poured into the North Atlantic and Arctic Oceans. This vast pulse, a greater volume than all of North America's Great Lakes combined, diluted the North Atlantic conveyor belt and brought it to a halt.
No evidence of an extraterrestrial impact 13,000 years ago, studies say. An independent study has cast more doubt on a controversial theory that a comet exploded over icy North America nearly 13,000 years ago, wiping out the Clovis people and many of the continent's large animals.
Lake Sediments Cast More Doubt That a Comet Caused Ice Age Extinctions After combing through layers of ancient lake sediments, palaeoecologist Jacquelyn Gill of the University of Wisconsin-Madison says her team has found no evidence to support a controversial comet theory for an ice age extinction event.