Here's another cool theory on the extinction of dinosaurs which involves multiple asteroids hitting each other and then showering Earth with chaos:
"A colossal collision in space 160 million years ago set the dinosaurs on the path to extinction, a study claims. An asteroid pile-up sent debris swirling around the Solar System, including a chunk that later smashed into Earth wiping out the great beasts.
Other fragments crashed into the Moon, Venus and Mars, gouging out some of their most dominant impact craters, a US-Czech research team believes. Its study, based on computer modelling, is reported in the journal Nature.
"We believe there is a direct connection between this break-up event, the asteroid shower it produced and the very large impact that occurred 65 million years ago that is thought to have wiped out the dinosaurs," Dr Bill Bottke from the Southwest Research Institute, Boulder, Colorado, US, told BBC News."
...by the way I have my own theory which is that the dinosaurs spent all of their time studying the previous mass extinction of the Late Devonian extinction and forgot to pay their rent.