Earth Observing System (EOS) Terra, Aqua and Aura are NASA missions to study the earth's ozone, air quality and climate.
The EOS Aqua and Aura satellites, instruments, launch, and science investigations are all managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland. The satellites were launched in May 2005 (Aqua) and July 2004 (Aura) and will be operated for five or more years.
The MODIS instrument on the EOS Aqua satelluite shows chlorophyl in the Gulf of Alaska (image NASA)
The Aqua mission was designed exclusively to study the oceans, while Aura conducts research on the composition, chemistry and dynamics of the earth's upper and lower atmosphere employing multiple instruments on a single satellite. EOS Aqua and Aura are the second and third in a series of three major earth observing satellites to study the environment and climate change and is part of NASA's Earth Science Enterprise. The first mission, Terra, was designed to study the land and the earth's radiation budget.
http://eos.gsfc.nasa.gov/
