TIMED Artist Concept (IMAGE) NASA/Goddard Space Flight Center Caption Shown in this artist's concept, NASA's TIMED spacecraft has been observing Earth's upper atmosphere for 15 years, leading to new understandings of how this region interacts with the lower atmosphere below and space above -- and now, how the very same chemistry may play out on exoplanets. Credit NASA/JHU-APL Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.