The NASA MODIS Mission
MODIS (Moderate-resolution Imaging Spectroradiometer) is a payload scientific instrument launched into Earth's orbit by NASA in 1999 onboard the Terra Satellite, and in 2002 onboard the Aqua satellite. The program is a multi-national, multi-disciplinary mission involving partnerships with the aerospace agencies of Canada and Japan. Aboard the satellites the MODIS instruments image the entire Earth every 1 to 2 days. They are designed to provide measurements and images on a large-scale to capture changes in the Earth's cloud and ice cover, radiation budget and processes occurring in the oceans, on land, and in the lower atmosphere. 

MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning the protection of our environment.

(NASA, 2011, (Wikipedia, 2011,