When the Earth Had Two Moons: The Lost History of the Night Sky

An astonishing exploration of planet formation and the origins of life by one of the world’s most innovative planetary geologists.

In 1959, the Soviet probe Luna 3 took the first photos of the far side of the moon. Even in their poor resolution, the images stunned scientists: the far side is an enormous mountainous expanse, not the vast lava-plains seen from Earth. Subsequent missions have confirmed this in much greater detail.

How could this be, and what might it tell us about our own place ...