This image of Earths city lights was created with data from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS). Originally designed to view clouds by moonlight, the OLS is also used to map the locations of permanent lights on the Earths surface. The brightest areas of the Earth are the most urbanized, but not necessarily the most populated. (Compare western Europe with China and India.) Cities tend to grow along coastlines and transportation networks. Even without the underlying map, the outlines of many continents would still be visible. The United States interstate highway system appears as a lattice connecting the brighter dots of city centers. In Russia, the Trans-Siberian railroad is a thin line stretching from Moscow through the center of Asia to Vladivostok. The Nile River, from the Aswan Dam to the Mediterranean Sea, is another bright thread through an otherwise dark region. Even more than 100 years after the invention of the electric light, some regions remain thinly populated and unlit. Antarctica is entirely dark. The interior jungles of Africa and South America are mostly dark, but lights are beginning to appear there. Deserts in Africa, Arabia, Australia, Mongolia, and the United States are poorly lit as well (except along the coast), along with the boreal forests of Canada and Russia, and the great mountains of the Himalaya.

This is what the Earth looks like at night. Can you find your favorite country or city? Surprisingly, city lights make this task quite possible. Human-made lights highlight particularly developed or populated areas of the Earths surface, including the seaboards of Europe, the eastern United States, and Japan. Many large cities are located near rivers or oceans so that they can exchange goods cheaply by boat. Particularly dark areas include the central parts of South America, Africa, Asia, and Australia. The above image is actually a composite of hundreds of pictures made by the Defense Meteorological Satellite Program (DMSP) currently operates four satellites carrying the Operational Linescan System (OLS) in low-altitude polar orbits. Three of these satellites record nighttime data. The DMSP-OLS has a unique capability to detect low levels of visible-near infrared (VNIR) radiance at night. With the OLS VIS band data it is possible to detect clouds illuminated by moonlight, plus lights from cities, towns, industrial sites, gas flares, and ephemeral events such as fires and lightning-illuminated clouds. The Nighttime Lights of the World data set is compiled from the October 1994 - March 1995 DMSP nighttime data collected when moonlight was low. Using the OLS thermal infrared band, areas containing clouds were removed and the remaining area used in the time series. This animation is derived from an image created by Craig Mayhew and Robert Simmon from data provided by Christopher Elvidge of the NOAA National Geophysical Data Center.

The Lights of Earth can be seen from space. Human-made lights highlight particularly developed or populated areas of the Earths surface, including the seaboards of Europe, the eastern United States, and Japan. Many large cities are located near rivers or oceans so that they can exchange goods cheaply by boat. Particularly dark areas include the central parts of South America, Africa, Asia, and Australia. The above image is actually a composite of hundreds of pictures made by the Defense Meteorological Satellite Program (DMSP) currently operates four satellites carrying the Operational Linescan System (OLS) in low-altitude polar orbits. Three of these satellites record nighttime data. The DMSP-OLS has a unique capability to detect low levels of visible-near infrared (VNIR) radiance at night. With the OLS VIS band data it is possible to detect clouds illuminated by moonlight, plus lights from cities, towns, industrial sites, gas flares, and ephemeral events such as fires and lightning-illuminated clouds. The Nighttime Lights of the World data set is compiled from the October 1994 - March 1995 DMSP nighttime data collected when moonlight was low. Using the OLS thermal infrared band, areas containing clouds were removed and the remaining area used in the time series.