A scorching-hot gas planet beyond our solar system is steaming up with water vapor, according to new observations from NASA’s Spitzer Space Telescope. The planet, called HD 189733b, swelters as it zips closely around its star every two days or so. Astronomers had predicted that planets of this class, termed „hot Jupiters“, would contain water vapor in their atmospheres. Yet finding solid evidence for this has been slippery. These latest data are the most convincing yet that hot Jupiters are „wet“.
https://www.spitzer.caltech.edu/news/ssc2007-12-nasas-spitzer-finds-water-vapor-on-hot-alien-planet