Cosmic Collisions

Cosmic collisions have forever shaped the planets in our solar system, sculpting Earth and our Moon. They are still happening right in our neighborhood, as we saw in July 1994 when comet fragments bombarded the surface of Jupiter. What if a collision of that magnitude were to occur on Earth? Would the effect be anywhere near that of the collision that wiped out the dinosaurs 65 million years ago? Scientists have just begun to track distant asteroids and comets that may pose a threat to Eart...