There are strong scientific indications that natural change in the Earth system is being accelerated by human intervention.  As a result, planet Earth faces the possibility of rapid environmental changes that would have a profound impact on all nations.  However, we do not fully understand either the short-term effects of our activities, or their long-term implications–many important scientific questions remain unanswered.  The National Aeronautics and Space Administration (NASA) is working with the national and international scientific communities to establish a sound scientific basis for addressing these critical issues through research efforts coordinated under the U.S. Global Change Research Program, the International Geosphere-Biosphere Program, and the World Climate Research Program.  The Earth Science Enterprise is NASA’s contribution to the U.S. Global Change Research Program.

NASA’s Earth Science Enterprise will use space- and surface-based measurement systems to provide the scientific basis for understanding global change. The space-based components will provide a constellation of satellites to monitor the Earth from space. A major component of the Earth Science Enterprise is the Earth Observing System (EOS).