The website physorg.com discusses the results of a study suggesting that a breakup in our solar system's asteroid belt created the meteors that eventually killed the dinosaurs.
Some of these bodies eventually found their way into the inner solar system and pummeled the Earth and the Moon. Some interesting geological study here, suggesting that it was a continuous bombardment over much time that created the conditions for dinosaur extinction. My 4-year-old dinophile geeklet loves regaling anyone who's interested about "how the dinosaurs died." Now dad's got his back with some ultra-current info!