A team of astronomers have identified oxygen and carbon in the atmosphere of a planet beyond the Solar System for the first time.
The orbiting Hubble Space telescope detected the oxygen and carbon bleeding off a giant gas-planet orbiting a star 150 light years from Earth.
The astronomers, led by Alfred Vidal-Madjar from the Astrophysics Institute of Paris, found that the oxygen naturally exists and is not produced by plant life.
The finding demonstrates that the chemical composition of atmospheres on planets many light-years away can be measured.
Scientists believe this could one day lead to the discovery of life on a planet in a distant star system.
The planet belongs to a class of gas planets called "hot Jupiters" because they are so close to their parent star.
Nothing could live on such a gaseous hot world. But if signs of oxygen were detected on a rocky planet further away from its star, it would be strong evidence of life existing there.
The planet has been named "Osiris" after the Egyptian god that lost part of his body after being cut to pieces by his brother to prevent his return to life.
The planet, in the constellation of Pegasus, was also the first extrasolar planet discovered transiting its sun, the first with an atmosphere, the first observed to have an evaporating hydrogen atmosphere and now the first to have an atmosphere containing oxygen and carbon.
PA