Many of the Apollo astronauts returned to Earth not only with a new interest in ecology, but with a sense of urgency. Gene Cernan, the last man to stand on the Moon, felt “My destiny was to be not only an explorer, but a messenger from outer space, an apostle for the future.” Michael Collins returned determined “that I would do all I could to let people know what wonderful home we have—before it is too late.” Edgar Mitchell thought about “beneath the blue and white atmosphere was a growing chaos…that population and conscienceless technology were growing rapidly way out of control.”

While universal peace and brotherhood did not immediately ensue after Apollo, Poole believes the Earthrise photo had important impact as a symbol for a new consciousness of the home planet that has changed attitudes, however slowly and subtly. It contributed to the power of new metaphors, from Spaceship Earth to Gaia, that guide our understanding and our resolve.

“The sight of the whole Earth, small, alive, and alone, caused scientific and philosophical thought to shift away from the assumption that the Earth was a fixed environment, unalterably given to humankind,” Poole concludes, “and towards a model of the Earth as an evolving environment, conditioned by life and alterable by human activity.”

Beginning with Earthrise, these images of the Earth from space have contributed to a more widespread sense of the Earth’s fragile status as the one known live world, and as the only Earth we’ve got. They contributed to the metaphors of Spaceship Earth and Gaia that guide our understanding and our resolve. But the urgency remains, and grows.

Though the Earth Blue Marble photo became even more iconic than the Apollo 8 image, there is a particular poignancy to Earthrise, because the planet is not all there. Some of it had not “risen” yet, but visually the missing portion suggests how fragile this life-bearing vessel is. Amidst the immense emptiness between the far-flung fires of stars, it could just as easily be setting, or dissolving life by life, leaving only another gray globe in the cold and darkness.

It’s up to us. We are the future we have been waiting for.