Riyadh, the national capital of Saudi Arabia, is shown in 1972, 1990 and 2000. Its population grew in these years from about a half million to more than two million. Saudi Arabia experienced urbanization later than many other countries; in the early 1970s its urban-rural ratio was still about 1:3. By 1990 that had reversed to about 3:1. The city grew through in-migration from rural areas, and from decreases in the death rate while birthrates remained high. The 1972 image is a Landsat MSS scene; the 1990 image is a Landsat Thematic Mapper scene; and the 2000 image is an ASTER scene. All three images cover an area of about 27 x 34 km. The image is centered at 24.6 degrees north latitude, 46.6 degrees east longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.