Moonfall

It's the 21st century, and all is right with the world. Or so it seems.
But all that is right is about to go disastrously wrong when an amateur astronomer discovers a new comet. Named for its discoverer, Tomiko is a "sun-grazer," an interstellar wanderer with a hundred times the mass and ten times the speed of other comets. And it is headed straight for our moon.
In less than five days, if scientists' predictions are right, Tomiko will crash into the moon, shattering it into a cloud of superheated gas, dust, and huge chunks of rock that will rain down on the earth, causing chaos and killer storms, possibly tidal waves inundating entire cities...or worse: a single apocalyptic worldwide "extinction event."
In the meantime, the population of Moonbase must be evacuated by a hastily assembled fleet of shuttle rockets. There isn't room, or time enough, for everyone. And the vice president, who rashly promised to be last off ("I will lock the door and turn off the lights"), is trying to figure out how to get away without eating his words.