The proponents of the theory said that they had found evidence of a comet impact, including magnetic microspherules, in the earth overlying 10 Clovis-age archaeological sites across North America.
University of Wyoming archaeologist Ted Surovell and several colleagues attempted to repeat the study and came up with startlingly different results.
Using the same methods, Surovell and his co-researchers were “unable to find high concentrations of magnetic particles and spherules” – even at the two sites previously studied by the original researchers
As noted previously, the comet hypothesis, while generating hubbub on the Googletubes, never explained how the strike caused megafauna extinctions. We’re left where we’ve always been: at the end of the Pleistocene, when some large animals died off, others lived on, and we have little explanation why any of it happened.
Photo courtesy of Noel Munford of the Palmerston North Astronomical Society, New Zealand (via NASA).