Nabro volcano, Eritrea, in the Horn of Africa, began erupting June 12, 2011, the first-ever recorded eruption of this stratovolcano. Over the next nine days, ash plumes sent into the stratosphere disrupted air traffic in Sudan, Djibouti, Ethiopia and Sudan. In this nighttime thermal image acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft on June 19, lava flows are bright white (hot), a small eruption plume is black (cold), and ash deposits are pinkish in color. Nabro is located along the Great Rift Valley, along with other volcanoes. The image covers an area of 3.8 by 3.8 miles (6.2 by 6.2 kilometers), and is located at 13.4 degrees north latitude, 41.7 degrees east longitude. The image resolution is 293 feet (90 meters).

With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products.

The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington, D.C.

More information about ASTER is available at http://asterweb.jpl.nasa.gov/.