Over the years, astronauts have taken over a million photographs of Earth from space, and many of them are closeup shots of the planet's cities, all lit up at night. A new project called Cities at Night pulls those images together (from NASA's giant Gateway to Astronaut Photography of Earth), and throws them on an interactive map. What makes these images special is that they're not just the products of some algorithm-driven satellite capturing data — they're each photos taken by actual humans. The image above, for example, was taken from the International Space Station on January 29 of last year using an ordinary (if high-end) SLR camera. (Can you guess what Canadian city it shows? The answer's in the gallery).
The site was created by a Spanish astrophysics organization for two reasons: to marvel at what humanity looks like from space, but also to draw attention to light pollution, or as the site puts it, "to show how much we have changed the ecosystem of the night." The site also calls on volunteers to help sift through the thousands of unclassified images from space to enrich the maps and "help governments and local authorities to make the right decisions to reduce light pollution."
The site points to the adverse effects on human and animal health of all that light, and the larger disruption to ecosystems that can result. Birds can be particularly sensitive to light pollution in the form of bright lights from tall buildings that stand in their migratory paths. That problem was tackled on the show earlier this season by a hawk (whose voice sounds eerily like Gilbert Gottfried):