After NASA’s Apollo 8 orbited the moon in 1968, its crew brought back with them the most stunning of photo souvenirs. “Earthrise,” taken by William Anders using 70mm color film, pictured our planet as a distant orb in the vastness of outer space—an image that would come to stand for humanity and, eventually, the environmental zeitgeist, popularized on the covers of Stewart Brand’s Whole Earth Catalog and forever imprinted in the public mind. As Anders later said, “We set out to explore the moon and instead discovered the Earth.”