http://aura.gsfc.nasa.gov/index.html
The NASA Aura Program is a satellite mission that aims to study Earth’s atmosphere and understand how it affects air quality, climate, and the overall environment. Launched in 2004, the Aura satellite carries four sensors that are used to measure the levels of various gases and aerosols in the atmosphere. The data collected by the Aura satellite is used to create detailed maps of air quality, track the movement of pollutants, and help scientists better understand the impact of human activity on the environment. Overall, the NASA Aura Program plays a critical role in helping us better understand and protect our planet.