This photograph of the central Sahara Desert was taken from the International Space Station shortly after sunrise. The tan colors of the vast Marzuq Sand Sea in the foreground (300 kilometers or 190 miles across) contrast with the black lavas of the Tibesti Mountains near the horizon. This sand sea is one of the most recognizable features for orbiting astronauts, partly because they see it often through cloudless Saharan skies.
Taken with a 17 mm lens, this view replicates closely what the human eye sees. This lens gives a strong three-dimensional sense because the Earth curves away visibly toward the horizon and the few clouds cast shadows toward the camera. The lens even captures the effect of different sun elevations: The eastern Sahara on the horizon is in full daylight, but the Sand Sea in the foreground is darker where Sun is just rising.
Astronaut photograph ISS042-E-16183 was acquired on November 26, 2014, with a Nikon D4 digital camera using a 17 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 the Expedition 42 crew. It 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 M. Justin Wilkinson, Jacobs at NASA-JSC.