Chance of life on new planet '100%'

This artist's conception shows the inner four planets of the Gliese 581 system and their host star, a red dwarf star only 20 light years away from Earth. By Lynette Cook at the NSF -Source: US National Science Foundation

It is not too hot and not too cold, and astronomers believe that a new planet detected outside our solar system may have a temperature that is just right to support life.
The planet, found by astronomers at the University of California, Santa Cruz, and the Carnegie Institution of Washington, is orbiting in the middle of the "habitable zone" and appears to be three times the mass of the Earth.

Steven Vogt, professor of astronomy and astrophysics at the University of California, Santa Cruz, and one of the leaders of the team that discovered the planet, said he had "no doubt" there could be life on the planet.

"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%," Vogt said.

He said the fact they were able to detect the planet so quickly tells them planets like it "must be" be common.

"There are now nearly 500 known extra-solar planets," Vogt's team wrote. "If the local stellar neighbourhood is a representative sample of the galaxy as a whole, our Milky Way could be teeming with potentially habitable planets."
The planet, called Gliese 581g, is 20 light-years away from Earth in the constellation Libra, according to the paper to be published in the Astrophysical Journal.
A light-year is the distance light can travel in one year at a speed of 300,000 km a second, or about 10 trillion km.
This planet, one of six whizzing around the little cool star, has a mass three to four times that of the Earth and orbits every 37 or so days, they calculated.
"Our findings offer a very compelling case for a potentially habitable planet," Vogt said.
They estimate temperatures on the planet average from -31 to -12 degrees Celsius. The planet is locked facing its sun, like Mercury, so one side would be extremely hot and the other perpetually cold, with the liveable range being at the edge where dawn and dusk would be on a spinning planet like Earth's.
If it was rocky, like Earth, it could have gravity similar to Earth's and it would be possible for liquid water to be on the surface, they said, although they have not detected water on Gliese 581g.