Ambrym volcano in Vanuatu is one of the most active volcanoes in the world. A large summit caldera contains two active vent complexes, Marum and Benbow. In this February 12, 2014 ASTER nighttime thermal infrared image, the bright white spots are active lava lakes in the vent complexes. The purple area to the left of the vents is an area covered by recent volcanic ash. The black "cloud" coming from the eastern vent is a small eruption plume. The caldera appears as a circular blue-grey area in the central one-fourth of the island. The image covers an area of 45 by 30 kilometers (28 by 18.6 miles) and is located at 16.2 degrees south, 168.1 degrees east.

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/.