It took millions of years for life to recover and surpass its previous diversity, this time with a new ensemble of species that included our distant ancestors. Many scientists believe that about three-quarters of animals, including the pterosaurs, the mosasaurs and, as every child now knows, the non-avian dinosaurs were wiped out as a result. As it hit with a force equivalent to more than 100m megatons of TNT, or about 1,500 times the total content of the world's present nuclear arsenals, the asteroid sent a vast cloud of scalding vapour thousands of miles in all directions, and blasted more than 50 times its own mass of pulverised rock high into the sky where, as tiny particles, it incandesced and heated the entire atmosphere to several hundred degrees centigrade, killing almost everything unprotected by soil, rock or deep water.
O ne day around 66m years ago – it was in June or July if the evidence from fossilised pollen traces has been interpreted correctly – an asteroid somewhat larger than Manhattan ploughed into the Earth near what is now Chicxulub in the Yucután Peninsula, Mexico at 45,000 mph.
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