ASTER's Global Perspective A <a href="http://www.apple.com/quicktime/">Quicktime</a> or equivalent viewer is necessary to view this movie The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is the only instrument aboard Terra that does not operate continually on orbit. The instrument collects an average of 8 minutes of data per 98-minute orbit. It will take ASTER roughly 5 years to assemble a global data set at resolutions of up to 15 meters per pixel. From these data, the ASTER Team will assemble a very detailed digital elevation map of our planet's surface.