Maybe like me, you thought this image was of a mountain, climbing out of a snowy plain. In fact, it is a satellite photo taken of the Namib desert, in Namibia. The snowy plain is in fact a sand sea – a giant area filled with little but wind-blown sands. It has the appearance of ice and snow because the sand has a high level of reflectivity or albedo, bouncing the light back into space. The hills in the center of the image are devoid of sand, causing them to reflect different amounts of light back.
This region of Africa has been arid for millions of years. The cause lies in its geography. Lying on the western coast of Africa, it sits next to the cool waters of the Atlantic Ocean. Air masses in the region get cooled by the ocean, precipitating out their rain over the waters. By the time the air masses travel over the land, they are nearly devoid of water, and so rain hardly ever falls. It’s the same reason why the Atacama desert exists in South America (just replace Atlantic with Pacific).
This image was taken by the Advanced Visible and Near Infrared Radiometer on board the Advanced Land Observing Satellite, which waslaunched in in 2006. It has produced many fascinating images, but unfortunately shut down permanently last year when engineers tried to set it to conserve energy.
Source: Alaska Satellite Facility