What is the novel, Life As We Knew It, about?

Life As We Knew It is a survival story in which the moon is hit by an asteroid and is knocked into a closer orbit. This affects the tides and the volcanoes, causing chaos on earth. This leads to a breakdown of civilization and food shortages. Life as people once knew it is over, and the narrator and her family have to struggle to survive as their electricity, fuel, water and food runs out.