Astronauts aboard the International Space Station took this photograph when the desert center of Arabia was partly obscured by a dusty atmosphere. With slight image enhancement, a wealth of detail appears—most strikingly, the swaths of red dunes, the straight lines of rock ridges, and the city of Riyadh (capital of Saudi Arabia).
Riyadh means “The Gardens,” which aptly explains why the greens of this urban region of 5.7 million people contrast with the dun (gray-brown) desert landscape. The dark stipple of crops is concentrated near ancient water courses, where underground water is more readily available for irrigation. The upper left of the image is dominated by the tracery of gully-eroded hillsides.
Astronaut photograph ISS042-E-1170 was acquired on November 9, 2014, with a Nikon D4 digital camera using a 100 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.