Bestselling author of Warped Passages and Knocking on Heaven's Door and one of today's most influential and highly cited theo-retical physicists, Professor Lisa Randall once again effortlessly delivers fascinating science to the general reader. Weaving together the cosmos' his-tory and our own in an expanding intellectual adventure story, Dark Matter and the Dinosaurs takes us from the mysteries of dark matter and our cosmic environment to the conditions for life on Earth. Sixty-six million years ago, an object the size of a city descended from space to crash into Earth, creating a cata-clysm that killed off the dinosaurs, along with three-quarters of the other species on the planet. What was its origin? Randall proposes it was a comet that was dislodged from its orbit as the Solar System passed through a disk of dark matter that is embedded in the plane of the Milky Way. Her research challenges the usual assumptions about the simple nature of dark matter and demonstrates how scientists formulate and establish new ideas. In a sense, it might have been dark matter that killed the dinosaurs.