Taken by astronauts from windows in the International Space Station, this image shows the complex pattern of city lights in the metropolitan region of Cairo-the largest city in the Middle East and Africa's second largest city after Lagos (Nigeria). The brightly lit areas show greater Cairo with a population of about 20.5 million, fully a fifth of Egypt's population. Lights of the newer extensions of the city such as New Cairo, Sixth of October City, El Abor, and El Shorok, show a distinctly yellower color, probably related to sodium-vapor streetlight lamps. New Cairo is being constructed as the new capital city of Egypt.
Less prominent are the lights of numerous towns and villages on the Nile Delta (upper half of the image) and on the narrow floodplain of the River Nile (image lower left). The River Nile can be detected in places as a black line wending its way through Cairo itself.