This was Milton Glaser’s first environmental poster, created for the Environmental Action Coalition, a New York City- based nonprofit that focuses on recycling and environmental education in schools. In December 1968, the astronauts of Apollo 8—the first crewed spaceflight to reach the moon—returned with the legendary Earthrise photograph, showing the earth peeking over the moon’s horizon. Photographer Galen Rowell of National Geographic magazine called it “the most influential environmental photograph ever taken,” and in the Christmas Day issue of that year’s New York Times, the poet Archibald MacLeish wrote: “To see the earth as it truly is, small and blue and beautiful in that eternal silence in which it floats, is to see ourselves as riders on the earth together.” Given the instantly iconic status of this image, it is possible Glaser was inspired by it when he created this poster.