Dominating the top third of Africa is the Sahra Desert, Earth's largest band of dry land. Stretching across the Sahara are vast plains of sand and gravel, seas of sand dunes and barren rocky mountains. Only 10,000 years ago grasses covered the region and mammals such as lions and elephants roamed the land.
Dominating the top third of Africa is the Sahra Desert, Earth’s largest band of dry land. Stretching across the Sahara are vast plains of sand and gravel, seas of sand dunes and barren rocky mountains.
Only 10,000 years ago grasses covered the region and mammals such as lions and elephants roamed the land. Now only two percent of the Sahara hosts oases, patches of land usually centered on natural water springs where crops will grow and where nearly two million people live. This image, taken by Landsat 7, is of a colorful and rocky expanse spanning about 50 kilometers near the Terkezi Oasis in Chad.Image credit: NASA