Popocatepetl, the nearly 18.000-foot-high (5,400 meters) volcano about 40 miles (60 kilometers) southeast of Mexico City, continues to spew water vapor, gas, ashes and glowing rocks from its latest eruption, which started in mid-April 2012. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft acquired this nighttime image on April 25, 2012. Three thermal infrared channels are combined to highlight the long volcanic plume blowing toward the south. The blue color indicates that its composition is mostly water vapor. A small hotspot can be seen in the summit crater as a bright spot. The image covers an area of 3.3 by 7.7 miles (5.3 by 12.4 kilometers) and is located at 19 degrees north latitude, 98.6 degrees west longitude.
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/.