NASA has collected a staggering 1.3 million pictures of Earth taken from the International Space Station – about a third of them taken at night. But the problem is they don't know what many of the pictures are of, which is why they need the help of the public to identify the location of the images.
The Complutense University of Madrid has launched a crowdsourcing project called Cities at Night to sift though the space station's nighttime imagery, sort it into categories and then match images to specific map references.
It's not going to be as easy as it sounds. To an astronaut north and south aren't really very useful concepts and so there is no telling the orientation of the pictures, or which way the astronaut was pointing the camera when the picture was taken.
It's not a job that can be automated either, as the project's website says:
Your collaboration is really important because algorithms cannot distinguish between stars, cities, and other objects (i.e. moon).
The project has a practical purpose – the main objective of collating all this data is to study light pollution that comes from cities.