Astronaut and International Space Station Science Officer Don Pettit shot this beautiful time lapse of the Earth rotating through the day and night cycle.
It's pretty amazing how bright our cities are at night. Pettit's video also shows to great effect just how relatively thin our atmosphere is. It's easy to think it is without end while staring up at the sky from a grassy field, but when you really get up there and see it from this angle, you realize how little space we have to work with. If we screw it up, there's nowhere else to go.