Routinely going through daily life, people may be inured to the fact that Earth takes up only a small fraction of a solar system, let alone the universe. Still, the planet we call home is unique for a number of reasons. The more we can learn about Earth and its Moon, the more likely scientists are to uncover truths about the universe as a whole. The properties, motions, and cycles that characterize the Earth and Moon are the subjects of this mesmerizing...