NASA’s Earth Observatory has a page of photos of cities at night taken from space; at right, Tokyo. “Astronauts circling the Earth have the wonderful vantage point of observing the nighttime Earth from 350-400 kilometers above the surface, taking in whole regions at once. Onboard cameras and a bit of experimentation allow astronauts to take highly detailed images of our cities at night and share them with the rest of us.” In addition to photos, an explanation of how it’s done. Via Kottke.