Unlike August 14, 2003, the bustling U.S. East Coast is normally ablaze in nighttime light, with its cities growing closer and closer together. NASA researchers use these images of nighttime lights to study weather around urban areas. Weather stations were classified as urban, near-urban or rural depending on the brightness around them and their records adjusted to account for human influence. These images are actually a composite of hundreds of pictures made by U.S. Defense Meteorological Satellites Program (DMSP). The Nighttime Lights of the World is compiled from the October 1994 - March 1995 data, which was collected when moonlight was low.
For more information on how this image was created, visit the Scientific Visualization Studio.
For more information on how NASA uses these images for research, visit the Satellites Shed Light on a Warmer World site.