NASA says water found on exoplanet

July 12, 2007

NASA says that the Spitzer Space Telescope has detected water vapour on HD 189733b, a massive exoplanet orbiting the dwarf star HD 189733, "trillions of miles" outside our solar system. The water vapours were found in the planet's atmosphere.

"We're thrilled to have identified clear signs of water on a planet that is trillions of miles away," said Giovanna Tinetti, a European Space Agency researcher and main author of NASA's study, at the Institute d’Astrophysique de Paris France.

The planet, termed a "wet Jupiter", takes approximately two days to orbit its sun and its surface temperatures are estimated to be at least 1,000 Kelvin (1,340 Fahrenheit/727 Centigrade) which, according to scientists, makes it unlikely that life would exist there. The presence of water was observed by using the telescope to examine the absorption spectra as the planet transited across its star.

"Finding water on this planet implies that other planets in the universe, possibly even rocky ones, could also have water," said co-author Sean Carey of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena.

Similar evidence for another hot gas giant, previously gathered using the Hubble telescope, was not widely accepted due to experimental noise and similar concerns.

HD 189733b is located 63 light-years away from Earth in the constellation Vulpecula.