12 Sep 2016 http://www.pnas.org/content/112/32/E4344.abstract A cosmic impact event at ∼12,800 Cal B.P. formed the... http://www.pnas.org/con…
Clemont Harms, 14 Aug 2015 A gigantic cosmic impact, when large fragments of a disintegrating comet hit the North American ice ... A gigantic cosmic impact…