The British and Irish Meteorite Society

The team carried out computer simulations that showed that, surprisingly, the avalanches do not seem to be caused by meteorites hitting the ground, but by the shock wave generated by a rock's passage through the atmosphere. This spreads across an area about a million times larger than the craters. "It was astonishing that a relatively small impact could affect a large area," says team member Jay Melosh of Purdue University in West Lafayette, Indiana.