New planet found in 'Habitable Zone'

Friday, October 1, 2010

Astronomers at the University of California at Santa Cruz have discovered a new planet which is considered to be in the middle of the Habitable Zone of its parent star, a discovery which has raised the possibility of finding life on another planet. Researchers found the planet while conducting the Lick-Carnegie exoplanet survey of Gliese 581, a red dwarf. The planet, named 'Gliese 581 g', is approximately 20 light years away from Earth and is hypothesised to have a generally rocky landscape with enough gravitational pull to accumulate an atmosphere.

The orbits of planets in the Gliese 581 system compared to those of our own solar system
Image: Zina Deretsky, National Science Foundation.

Steven Vogt of the University of California stated that Gliese 581g potentially has a gravitational pull similar to that of Earth, which would allow humans to walk around upright on its surface although human inhabitation of the planet is in no foreseeable future. Vogt observed that there is a significant possibility that life exists on Gliese 581 g.

"Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 per cent," Vogt said. Only lichen, bacteria and other micro-organisms are expected to exist on the planet.

Gliese 581 g is thought to have a temperature range from extremely hot to freezing cold depending on the side with respect to its star. The average temperature is expected to range from −31 to −12 degrees Celsius.

Prior to this discovery, two other planets were discovered in the low or "cold" end and the high or "hot" end of the 'Habitable Zone', respectively, orbiting the same star.


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