The city lights of Spain and Portugal define the Iberian Peninsula in this photograph from the International Space Station (ISS). Several large metropolitan areas are visible, marked by their relatively large and brightly lit areas, including the capital cities of Madrid —near the center of the peninsula’s interior— and Lisbon — along the southwestern coastline. Seville, visible to the north of the Strait of Gibraltar, is one of the largest cities in Spain.
The network of smaller cities and towns along the coastline and in the interior attest to the extent of the human presence on the Iberian landscape. The blurring of city lights is caused by thin cloud cover (image left and center), while cloud tops are dimly illuminated by moonlight. Though obscured, the lights of France are visible near the horizon line on the upper left, while the lights of northern Africa are more clearly discernable at right. The faint gold and green line of airglow—caused by ultraviolet radiation exciting the gas molecules in the upper atmosphere—parallels the horizon (or Earth limb).
Source: Nasa Earth Observatory