Earth at Night
Europe, Northern Africa, Eastern Asia, and Greenland
|Streetlights are the source of most of the light seen in this image, but petroleum fires also contribute. A dark blue layer was added to the image to show where land masses are located. European cities are especially bright, and in Egypt, lights glitter along the Nile. Such images have been used to estimate global urban populations.
Courtesy Marc Imhoff, Craig Mayhew, Robert Simmon NASA/GSFC; Christopher Elvidge NOAA/NGDC