Water Discovered In Exoplanet Atmosphere

PattonPending sends news of the discovery of the smallest exoplanet yet to have water vapor in its atmosphere. Astronomers have detected water vapor in the atmosphere of a planet that orbits a star far beyond our solar system. Observations of the Neptune-sized planet, which lies 120 light years from Earth in the constellation of Cygnus, revealed that its atmosphere was mostly hydrogen with around 25% made up from water va-pour. Until now, researchers have been frustrated in their efforts to study the atmospheres of planets much smaller than Jupiter because their skies were thick with clouds. The problem was so persistent that astronomers had begun to think that all warm, small planets formed with substantial cloud cover. But writing in the journal Nature, scientists in the U.S. describe how they found a Neptune-sized planet with cloud-free skies, enabling them to make detailed measurements of a small planet's atmosphere for the first time.