The U.S. space agency says its Hubble Space Telescope has discovered carbon dioxide in the atmosphere of a planet orbiting another star.

The National Aeronautics and Space Administration said the discovery is an important step toward finding chemical biotracers of extraterrestrial life.

Although the extrasolar, Jupiter-sized planet called HD 189733b is too hot for life, NASA said the Hubble observations are a proof-of-concept demonstration that the basic chemistry for life can be measured on planets orbiting other stars. NASA scientists also said organic compounds also can be a byproduct of life processes and their detection on an Earthlike planet someday might provide the first evidence of life beyond our planet.

"Hubble was conceived primarily for observations of the distant universe, yet it is opening a new era of astrophysics and comparative planetary science," said Eric Smith, NASA's Hubble program scientist. "These atmospheric studies will begin to determine the compositions and chemical processes operating on distant worlds orbiting other stars. The future for this newly opened frontier of science is extremely promising as we expect to discover many more molecules in exoplanet atmospheres."