Free Astronomy Magazine January-February 2018

24 EARTH Two Japanese researchers have concluded that the evolution of mammals from the Cretaceous to today would have been entirely different if the as- teroid which put an end to that period, 79 million years long and dominat- ed by dinosaurs, had fallen on areas with different petrological properties. The mass extinction caused by that event had only a thirteen percent prob- ability of occurring and leading to the appearance of humankind. Chicxulub: perfect timing... for us! by Michele Ferrara JANUARY-FEBRUARY 2018