Cosmic Rosetta Stone

Located about 1,500 light-years from Earth in the constellation Serpens, the planet Corot-9b passes in front of its star every 95 days, as viewed from Earth. Each of these "transits" lasts about eight hours.

When Corot-9b is positioned between its star and Earth, some of the light from its star passes through the exoplanet's atmosphere before continuing on to our planet.

By studying this filtered starlight, astronomers may be able to determine what molecules make up Corot-9b's atmosphere.

If that's the case, Corot-9b could become a "Rosetta stone" for exoplanet research, said study co-author Claire Moutou of the Laboratory of Astrophysics of Marseilles in France, referring to the artifact that helped decipher ancient Egyptian hieroglyphics.

(Related: "Distant Planet Mapped for First Time, "Hot Jupiter" Features Fierce Winds.")

"We hope that when we can investigate this planet, it will have characteristics which are close to other giant gas planets outside our solar system," Moutou said.

That's because Corot-9b's physical properties are thought to be representative of many gas giant exoplanets in our galaxy. So studying Corot-9b in detail could shed light on worlds that do not transit, and thus are impossible for astronomers to research.