The World at Night

NASA's Black Marble map of the Earth at night is the best way to view the distribution of artificial lights around the world. The Black Marble is a composite map made up of the best cloud-free satellite images of the Earth taken at night.

Cities at Night think that they can actually improve on NASA's Black Marble map. This citizen science project is using crowd-sourcing to identify the locations in night-time photographs of the Earth captured by astronauts on board the International Space Station. NASA has almost half a million of these pictures now. Many of them provide much higher definition aerial night-time views of towns and cities across the globe than can be found on the Black Marble map.

You can contribute to this new night-time map of the Earth by helping Cities at Night classify the locations in the photographs taken by astronauts from the ISS. You can also browse the 2,500 photographs classified so far on this map. The map shows the locations of night time images taken from the ISS identified by volunteers of Cities at Night.