In this brilliant exploration of our cosmic environment, renowned particle physicist and bestselling author of Warped Passages and Knocking on Heaven\'s Door, Lisa Randall uses her research into dark matter to illuminate the startling connections between the furthest reaches of space and life here on Earth.Sixty-six million years ago, an object the size of a city descended from space to crash into Earth, creating a devastating cataclysm that killed off the dinosaurs, along with three-quarters of the other species on the planet. What was its origin? In Dark Matter and the Dinosaurs, Lisa Randall proposes it was a comet that was dislodged from its orbit as the solar system passed through a disk of dark matter embedded in the Milky Way. In a sense, it might have been dark matter that killed the dinosaurs.