Today is the 40th anniversary of the Apollo 17 launch, the last manned mission to the moon. Most of the time, we think of those missions as directed outward, an exploration of space and a thrilling chance to get closer to the vast rest of the solar system. But the photos the astronauts took looking back toward Earth are informative, too, in a very different way. They provide a different perspective on our planet -- a blue marble floating alone, marvelous and fragile.

Now, NASA has released new photos of the Earth at night, taken by the Suomi NPP satellite earlier this year that show the planet as a black marble, not a blue one. These fabulous images looking down at Earth also provide a unique perspective. This time, it’s not just a beautiful swirl of clouds, but delicate pinpricks of light that outline human civilization. They remind us how pervasive and clustered we all are -- and how much light spills out of our cities and homes -- but also suggest just how little space we take up in space.