Viewed at night from the vantage point of the International Space Station, the regular north-south and east-west layout of street grids typical of western U.S. cities is clearly visible in this astronaut photograph of Salt Lake City. The color and density of the city lights provide clues to the character of the urban fabric.
Yellow-gold lights generally indicate major roadways. Bright white clusters are associated with city centers as well as commercial and industrial areas. Residential and suburban areas are recognizable as diffuse and relatively dim lighting.
Image courtesy of NASA.