Night Light

The military objectives of the US Air Force Defense Meteorological Satellite Program have created an aesthetic byproduct — a composite photo of the planet, taken during nighttime hours. More than 99% of these representations of actual light sources are indications of human activity on the planet. For example, this image includes more than a million man-made fires, most of them in the Third World, chiefly propagated for agricultural purposes. Population centers are easily identified; however, the amount of light represented here is not necessarily proportional to the population size. Imbalances arise due to unequal electrical consumption. Japanese consume 15 times as much electricity as Chinese per capita, and Americans consume 21/2 times more than Japanese do. This image also illustrates light pollution, a condition only astronomers have complained about so far.