WASHINGTON, Dec. 9 (Xinhua) -- Hubble Space Telescope has discovered carbon dioxide in the atmosphere of a planet orbiting another star, the U.S. space agency NASA reported on Tuesday.

This breakthrough is an important step toward finding chemical biotracers of extraterrestrial life, said NASA.

The Jupiter-sized planet, called HD 189733b, lies 63 light-years away. It is too hot for life, but the Hubble observations are a proof-of-concept demonstration that the basic chemistry for life can be measured on planets orbiting other stars. Organic compounds also can be a by-product of life processes and their detection on an Earthlike planet someday may provide the first evidence of life beyond our planet.

Previous observations of HD 189733b by Hubble and the Spitzer Space Telescope found water vapor. Earlier this year, Hubble found methane in the planet's atmosphere.

"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," said Eric Smith, Hubble program scientist at NASA.