Astronomers studying Gliese 581, a red dwarf star more than 20 light years away, have announced the discovery of a planet that may feature the most Earth-like conditions of any place ever observed outside our own solar system. Further study, however, is very difficult and it may take many years to learn any more information about the planet.

A European team of astronomers has discovered what may be the most Earth-like planet outside of our solar system , potentially capable of having liquid water and extraterrestrial life.

The planet, Gliese 581 c, named after the red dwarf star Gliese 581 that it orbits every 13 days, is about 20.5 light years away from Earth, the scientists report. Located in the constellation Libra, Gliese 581 is about one-third the mass of the sun and produces sunshine, so to speak, at least 50 times fainter than light emitted from our own star.

Because the new planet is much closer to its host star than the Earth is to the sun -- 14 times closer -- the planet may be capable of harboring life.

"We have estimated that the mean temperature of this super-Earth lies between zero and 40 degrees Celsius, and water would thus be liquid," explained Stéphane Udry, from the Geneva Observatory (Switzerland) the lead author of the paper reporting the result.

"Moreover, its radius should be only 1.5 times the Earth's radius, and models predict that the planet should be either rocky -- like our Earth -- or fully covered with oceans," he added.

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The astronomers found the new planet by using a spectrograph called High Accuracy Radial Velocity for Planetary Searcher (HARPS), which is located on the ESO 3.6-m telescope at La Silla, Chile. HARPS is able to measure velocities with a precision better than one meter per second and is used to detect exoplanets, which are planets located outside of our solar system.

By measuring movement of the host star, the discovery team was able to detect the presence of a planet within a certain size range -- at least 5 times the mass of the Earth, though it could also possibly be larger.