This is shelved in the "teen" section, but I heard about it on another blog and thought it sounded interesting. I was not disappointed! This is told as a diary of a teenage girl as she describes her experiences after an asteroid knocks the moon out of its usual orbit. The result is floods, volcanoes, and a kind of nuclear winter from all of the ash from the volcanoes. The style is very clean and the characters are interesting. I was happy to read on Amazon that there is a sequel of sorts coming out in June - not really a sequel, but a sort of parallel story about what happened in New York City during the same period. I think that is an interesting idea; one of the few flaws in this book is that the family is totally cut off from outside news, so we know very little of what is happening elsewhere.
Also, they spend a lot of the time hungry - food supplies are cut off. This made me hungry reading it, so be prepared with snacks. (I had the same problem with We the Living by Ayn Rand.)