Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a sensor onboard the Terra satellite , launched in December 1999. The Terra satellite also carries the MODIS sensor and follows a similar orbit to Landsat 7. ASTER is the result of a cooperative effort between NASA and Japan's Ministry of Economy, Trade and Industry (METI) and the Japan Space Systems (formerly ERSDAC).

ASTER data may be used for a range of applications including land-use studies, mapping, geology, water resources, coastal resources, environment and generation of digital elevation models (DEM).

The ASTER instrument consists of three separate instrument subsystems:

• Visible and Near Infrared (VNIR)
• Shortwave Infrared (SWIR) - No longer functioning 
• Thermal Infrared (TIR).