Mt. Etna, Italy erupted Tuesday, February 16, 2021, sending rivers of lava down the southeast flank of the volcano, and spewing ashes and volcanic stones over nearby villages. Sicily's Catania Airport was temporarily closed due to an ash plume that rose to 3700 m altitude. The ASTER nighttime thermal infrared data shows the extent of the active lava flows, draped over an older Google Earth image. The image was acquired February 17, 2021, covers an area of 38 by 39 km, and is located at 37.8 degrees north, 15 degrees east.

With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of about 50 to 300 feet (15 to 90 meters), 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 in Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington.

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