None
5 stars
Great hard sci-fi that doesn't pull any punches
This is a terrific book that treats its subject matter in a smart and thoughtful way. The premise is nothing new-there's a deadly asteroid heading straight for earth-but this threat is portrayed in the book in a realistic and thoughtful way. I found the sheer number of characters a little too much at times but nevertheless a great read, and highly recommended for sci-fi fans.