It is the current consensus that all the dinosaurs, and more than half of all life on earth at the time, were wiped out by  A six-mile-long asteroid, which struck Earth 66 million years ago, leaving a 124-mile-wide crater underneath the Gulf of Mexico’s Yucatán Peninsula. It now appears that this may not have been a single isolated impact. As an article in The Independent puts it, "Until now, it had been assumed that the asteroid acted alone. This week, scientists at Scotland’s Heriot-Watt University have published new three-dimensional images of a crater made by a second asteroid that hit Earth at around the same time off the coast of West Africa. The 5-mile-wide Nadir Crater was found nearly a thousand feet under the floor of the Atlantic Ocean. Siesmic imagery was needed to establish what had made the crater, but it does appear to be the result of an asteroid strike, which may also have occurred at the same time as the "CT Boundary" between the age of the dinosaurs an