These giant mountain sized boulders from space have wrought death and destruction throughout the millennia but until recently geologists could find no evidence that they had actually struck the earth. How the Earth Was Made follows the remarkable detective story that begins at Meteor Crater in Arizona as mining engineers desperately try to unearth the billion dollar iron boulder they thought was lying there. It's a detective story that also uncovers immense riches; the world's biggest nickel deposit in Sudbury, Canada, vast oil reserves in the Gulf of Mexico and a Gold mine in South Africa - all the result of asteroid impacts. Evidence is also unearthed of violent impacts that decimated some of the first people to live in America. And finally Asteroids, and their smaller cousins Meteorites, could also hold clues to the formation of the early earth and perhaps life itself.