Their hope is that Terra can broaden our understanding of the planet in much the same the way as Hubble has opened up new views on the cosmos. As an example, scientists at Wednesday's briefing at NASA Headquarters unveiled a montage of images of the Himalayan plateau captured by Terra on a single pass from orbit. First, the satellite saw heavy moisture in the atmosphere, typical for the Himalayas this time of year. That brought rain, which in turn made vegetation grow. Then Terra saw high levels of haze generated by automobiles and industries on the Himalayan plateau, home to half a billion people.
Water vapor is by far the dominant greenhouse gas.
On a practical level, data from Terra may help in managing crops and coastal fisheries and assessing natural hazards like earthquakes, floods and fires. About the size of a school bus, Terra will record spectral data from the visible to the infrared, covering the entire surface of Earth every 16 days. It reached its final orbit in February and is expected to be operational for six years. Aqua, is scheduled to be launched late this year. By the year 2005, NASA expects to have a fleet of 30 Earth-science satellites circling the planet.