Comet Crash

From publisher blurb: During your summer internship at the Kimball Science Observatory, you discover a comet headed straight for where your family lives. It's possible the comet will just graze the Earth's atmosphere. But you know there's a good chance the comet will either strike the city of Los Angeles or crash into the Pacific Ocean, causing an enormous tidal wave to sweep throughout the country. The President orders NASA to fire a missile to change the comet's collision course. People are fleeing from the area. Your parents can't decide what to do and turn to you for advice. What do you suggest?