Earth At Night

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. 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.

Some regions remain thinly populated and unlit. Antarctica is entirely dark. The interior jungles of Africa and South America are mostly dark. Deserts in Africa, Arabia, Australia, Mongolia, and the United States are poorly lit as well (except along the coast and rivers), along with the boreal forests of Canada and Russia, and the great mountains of the Himalaya.