Amazing Mars Atmosphere and Volatile EvolutioN Mission (MAVEN )Imaging Ultraviolet Spectrograph in Mars ! The philosophy of NASA's Mars Program has been "Follow the water," but "Where did the atmosphere go?" is still a lingering question. Although fluvial features such as dry riverbeds are visible on Mars, the atmosphere today is too thin to support liquid water, implying that Mars once had a thicker atmosphere that was lost to space. NASA's Mars Atmosphere and Volatile EvolutioN Mission, or MAV