Organic molecules essential for life have been detected in another hot gas planet outside the solar system, within a year by scientists from the National Aeronautics and Space Administration.
Scientists at NASA's Jet Propulsion Laboratory in California detected water, methane and carbon dioxide -- the basic chemistry for life -- in the planet named HD 209458b, NASA said.
The data from Hubble Space Telescope and Spitzer Space Telescope -- NASA's two orbiting observatories -- was used to detect the planet bigger than Jupiter.
"It's the second planet outside our solar system in which water, methane and carbon dioxide have been found, which are potentially important for biological processes in habitable planets," said Mark Swain, one of the researchers at NASA.
The finding follows the December 2008 discovery of carbon dioxide around another hot, Jupiter-size planet -- HD 189733b -- on which water vapour and methane were earlier detected.
"Detecting organic compounds in two exoplanets now raises the possibility that it will become common place to find planets with molecules that may be tied to life," Swain said.
The new finding have advanced the astronomers toward the goal of being able to distinguish planets where life could exist from those where life cannot exist.
HD 209458b orbits a sun-like star about 150 light years away in the constellation Pegasus. The planet is not habitable but has the same chemistry that, if found around a rocky planet in future, could indicate presence of life.