In this engaging and accessible exploratory work, accomplished astrophysicist Neil F. Comins shows how ten hypothetical astronomical situations would affect our planet and life on it. What if the Moon didn't exist, for example? The Earth would be rotating much faster than it presently does, tides would be lower, and life would be much more primitive than it is today. What if the Moon Didn't Exist? has been made into TV, radio, planetarium, and theater shows, and became the theme to Mitsubishi's pavilion at the World Expo in Nagoya, Japan in 2005. Praise for What if the Moon Didn't Exist "...a new genre...Seductively cunning...All these "what-ifs" have the cumulative effect of making us excruciatingly aware of what a special and precarious place we inhabit - and how easy it would have been for it to be otherwise." -The Washington Post "Imaginative and stimulating." -Booklist "Comins's scientific expertise is dizzying. It takes a rare writer to manipulate so many unknown factors with such ease and convincing detail. This book will thrill everyone who can't help wondering "what if..." -Astronomy Book Club