Snow and Sand in Central Asia

In December 2018, an astronaut on the International Space Station (ISS) took this highly oblique photograph of snow on the eastern Tien Shan and Taklimakan Desert in Central Asia. The Tien Shan (or Tian Shan) is one of the longest continuous mountain ranges in the world, stretching across 1,500 miles (2,500 kilometers) in northwest China, Kazakhstan, and Kyrgyzstan.

The Tien Shan Mountains, sometimes called Central Asia’s Water Tower, provide essential fresh water to the area. Since the Taklimakan Desert is a low-lying basin enclosed by mountain ranges on three sides, a rain shadow keeps the region extremely dry for most of the year.

The Tien Shan hold many of Asia’s major glaciers. In the spring and summer, the melting of ice and snow replenishes local rivers and transports eroded sediment to valleys. Alluvial fans deposit sediment perpendicular to the surrounding mountain ranges that get reworked, eroded, and transported farther by wind.

The Taklimakan is dominated by sand dunes with easily mobilized sediments. Winds in this region are capable of producing large dust storms. In this image, snow extends from peaks and valleys of the Tien Shan to the lower desert floor of the Taklimakan Desert. The Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites also offer a more quantitative view of snow cover in the region on the same day. Blankets of snow are visible on the desert through dusty haze, which obscures Bosten Lake.

Astronaut photograph ISS057-E-111453 was acquired on December 5, 2018, with a Nikon D5 digital camera using a 65 millimeter lens and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 57 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Andrea Meado, Jacobs Technology, JETS Contract at NASA-JSC.