Madrid at night in 2012

Madrid, capital of Spain, at night, as seen by ESA astronaut André Kuipers aboard the International Space Station in 2012.

André used a digital camera with 180 mm-lenses to take this picture from the International Space Station.

Colour pictures taken from the International Space Station are the best source for scientists to map artificial light at night.

Images have been colour-calibrated connecting measurements of light pollution and sky brightness from space and on the ground in order to give an accurate representation.

Over the last two decades astronauts are witnessing from space how cities shine whiter at night as new street lighting technologies were introduced.