An International Space Station crew member took this striking photograph one evening in late February. The image takes advantage of the Sun’s low angle to reveal linear geological structures of the Iranian mountain range bordering the western edge of the basin known as Dasht-e-Lut. The range rises 1,818 meters (6,000 feet) above sea level and lies 750 kilometers (466 miles) north of the Persian Gulf. The convoluted appearance results from erosion of folded and faulted rocks—softer rocks erode away quickly, leaving more resistant rock to form linear ridges that are perpendicular to the direction of compression. While not a major oil-producing region like the Zagros Fold Belt to the southwest, the mountains of east-central Iran contain economically important deposits of copper and other metals. Little vegetation can be seen from space in the arid interior basin of the Dasht-e-Lut. Iran is climatically part of the Afro-Asian belt of deserts that stretch from the Cape Verde islands off West Africa all the way to Mongolia near Beijing, China. The patchy, elongated, light-colored feature in the foreground (parallel to the mountain range) is the northernmost of the Dasht dry lakes that stretch southward 300 kilometers (186 miles). In near-tropical deserts, elevated areas capture most precipitation. Agricultural fields that depend on this precipitation appear as small dark patches in this image. They are located downslope, near the margin of the lake’s dry, salty soils. Astronaut photograph ISS012-E-18779 was acquired February 28, 2006, with a Kodak 760C digital camera using an 180 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center. The image in this article has been cropped and contrast enhanced; lens artifacts have also been removed. The International Space Station Program supports the laboratory 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. Source: http://earthobservatory.nasa.gov/Front Page |