The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft captured this image of the growing oil spill in the Gulf of Mexico on May 7, 2010. On April 20, 2010, an explosion destroyed the Deepwater Horizon oil platform operating in the Gulf of Mexico 80 kilometers (50 miles) offshore, resulting in substantial loss of life and releasing 5,000 barrels of oil per day into the water. The huge oil slick was being carried towards the Mississippi River Delta, and small amounts of oil had reached the Louisiana, Alabama, and Mississippi shores by May 3.
This ASTER image covers an area measuring 60 by 240 kilometers (37 by 147 miles). The image is a thermal image, with the coldest surfaces appearing dark, and the warmest appearing white. The city of Pascagoula, Miss., is visible in the upper right corner; at night the land is colder (darker) than the Gulf waters. Offshore islands also appear dark compared to the surrounding ocean. The black dots and patches are small clouds, particularly in the southern half of the image. The thickest parts of the oil spill appear as dark grey, filamentous masses in the southern part of the image, extending off of the bottom. Other dark-light swirl patterns are water currents where different temperature water masses are visible.
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 December 18, 1999, on NASA's 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 the 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 ASTER 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/.