Should we be planning to establish settlements on the moon and Mars? To many, including a couple of billionaires, the idea has become almost an obsession. An unlikely husband and wife duo has spent years digging deeply into plans to colonize space. Their conclusion: not so fast.

We exist because of the moon. Rebecca Boyle relates the amazing story of how the moon, born of a cataclysmic collision with an infant earth, has shaped our history, our evolution, and even our very existence.