BALTIMORE - The Hubble Space Telescope has found methane in the atmosphere of a distant planet -- the same planet where water was found last year.

Such discoveries could aid efforts to find life on planets outside our solar system, scientists said Wednesday.

The organic molecule was detected in the atmosphere of a Jupiter-sized planet that circles a star 63 light-years away in the constellation Vulpecula. The planet, HD 189733b, is too close to a nearby star to support life as we know it. But researchers said the observations show the astronomers' technique for detecting essential life ingredients can be used on cooler, potentially habitable Earth-sized planets.

The Space Telescope Science Institute in Baltimore, which coordinates use of the Hubble, said the discovery was the result of observations in May.

Mark Swain of NASA's Jet Propulsion Laboratory in California who led the team that made the discovery, described the work as a "dress rehearsal for future searches for life on more hospitable planets." Swain is the lead author of a paper appearing in Thursday's issue of Nature.

However, Sara Seager, a Massachusetts Institute of Technology researcher who was not part of Swain's team, said finding organic molecules on more Earth-like planets will be much more difficult.

While methane is important -- one of four molecules that astronomers seek, along with water, carbon dioxide and oxygen -- it is mostly crucial as a byproduct of life, which is not the case on this planet, said Carnegie Institution of Washington astronomer Alan Boss.