The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is the zoom lens aboard NASA's Terra spacecraft. With its Visible and Near Infrared (VNIR) subsystem, ASTER has the ability to collect imagery at up to 15 meters per pixel spatial resolution, while its Thermal Infrared (TIR) subsystem produces images at up to 90 meters per pixel.
These ASTER false-color images were acquired over Braidwood Nuclear power plant in Illinois, located about 75 km (47 miles) southwest of Chicago near where the Illinois and Kankakee Rivers intersect. Braidwood Nuclear can be seen in the VNIR image (top) as the bright blue-whitepixels just above the large cooling pond. Like many power plants, Braidwood Nuclear uses a cooling pond to discharge heated effluent water. In this image, the red shades of the surrounding landscape show vegetated surfaces.
In the bottom image, a single ASTER Thermal Infrared band was color coded to represent heat emitted from the surface. The warmest areas are white; progressively cooler areas are colored red, orange, yellow, green, blue, and black for the coolest. Note the bright white plume of hot water discharged from the power plant. The water grows progressively cooler as it circulates around the pond.
Images courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.