An asteroid plummeting to Earth seems extremely unlikely, no wonder several movies have used it as a plot. But asteroids, comets, and meteorites do fall to Earth every day. In recent years, none have been of a significant enough size to cause great damage. However, it is theorized that a space object was responsible for the extinction of dinosaurs 65 million years ago. Readers will explore whether or not such an event could threaten life on Earth again, learn how scientists monitor asteroids and other space objects, and learn some theoretical plans to avoid a global catastrophe.