Dark Matter and the Dinosaurs

We all know that, about 66 million years ago, an asteroid slammed into what is now the Yucatan Peninsula of Mexico, and wiped out the land-based dinosaurs, and most other terrestrial life on Earth. But what we don't know is where that asteroid came from, and what caused it to slam into our planet.

Now in a new book, called Dark Matter and the Dinosaurs, The Astounding Interconnectedness of the Universe, Dr. Lisa Randall, a professor of particle physics and cosmology at Harvard University, proposes a new explanation.  She suggests that a disk of Dark Matter that crossed the plane of our galaxy, disturbed a comet in the Oort Cloud, and sent it hurtling toward Earth.