Stewart Brand knew the power of this photograph before it was publicly released. In 1966, “…he sold buttons which read, ‘Why Haven’t We Seen A Photograph of the Whole Earth Yet?’ Legend has it that this accelerated NASA’s making good color photos of Earth from distant space during the Apollo program and that the ecology movement took shape in 1968-9 partially as a result of those photos.”

Of course, the photo represented the present state of earth. And technically — like any photograph — it represents the past. But by showing us a whole new perspective, it conjured new ideas about how we share one planet rather than inhabit separate nations. It’s a powerful, tangible representation that implies potential for the future.