Water Vapor Plume (IMAGE) Naval Research Laboratory Caption The Sub Millimeter Radiometer on the European Space Agency’s Odin satellite observes the STS-135 water vapor plume at 99 km tangent altitude. Shown above (as the colored dots) are eight 12-hour time steps of the plume motion, which is north and east from the US east coast. This rapid transport is unexplained by standard models of upper atmospheric winds. Credit US Naval Research Laboratory 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.