When Galileo observed the Moon with his telescope, he was particularly attracted by the shadows on its surface. As he wrote in Sidereus Nuntius (1610), the shadows led him to recognize that there are mountains and valleys on the Moon, just like on the Earth. This discovery had important implications that Christian theologians were initially reluctant to accept, since the Earth and the Moon became “equivalent” celestial globes that shared reflections of the Sun’s light. Fifty years ago, when the astronauts of the Apollo mission landed on the Moon and saw the “Earthrise” with their own eyes, the vision of our world emerging from the darkness was deeply impressive ...
