An international team of researchers, including members of NASA Astrobiology Institute's (NAI) Virtual Planetary Laboratory team used NASA's Spitzer Space telescope to detect the presence of water vapor on the hot Jupiter Henry Draper (HD) Catalog 189733b. (The "b" after the number indicates that the reference is to a planet circling the star with that number.)
This is significant because several attempts to detect water on such planets either failed to find compelling evidence or made it clear that their claims should not be taken as fact. An article about this study was published recently in Nature magazine. The study's primary author, Giovanna Tinetti was a 2003 NAI Postdoctoral Fellow.