It is hard to say due to the star's brightness they haven't been able to do much study and trying to analyze something 20 light years away would be hard in itself.
It is the closest size planet to Earth in the habitable zone of a star or "goldilocks zone" known today, with a mass of about 3 to 4 times that of Earth. Because of its proximity to its star (Gliese 581, a red dwarf) it is expected to be tidally locked to its star (like the moon is to Earth - the same face always pointing to Earth). Which means that the temperatures could range from extremely cold on the side that is permanently night to blazing hot at the part always under the sun. In which case if it were habitable for humans liquid water would have to exist, in which if there is H2O then it will be liquid on the day side. It would also be seasonally locked with no axial tilt. If such predictions are true, then it may be at best habitable in a large circle surrounding the edge of the day side where it is cooler than in the middle of the day side.
In my opinion it would be very hard to find a planet with the same atmospheric composition as Earth's, eg. ~21% oxygen.
But, to put it all into perspective, our current fastest probe, Voyager 1, travels at 38000 mph, to travel 20 light years it would take ~353,000 years. I think by the time they can create faster space travel (even if we can get a Generation Ship to get life to there in about 1 millenium) we will have much better candidates, or a better understanding on Gliese 581g's atmosphere.
It is the closest size planet to Earth in the habitable zone of a star or "goldilocks zone" known today, with a mass of about 3 to 4 times that of Earth. Because of its proximity to its star (Gliese 581, a red dwarf) it is expected to be tidally locked to its star (like the moon is to Earth - the same face always pointing to Earth). Which means that the temperatures could range from extremely cold on the side that is permanently night to blazing hot at the part always under the sun. In which case if it were habitable for humans liquid water would have to exist, in which if there is H2O then it will be liquid on the day side. It would also be seasonally locked with no axial tilt. If such predictions are true, then it may be at best habitable in a large circle surrounding the edge of the day side where it is cooler than in the middle of the day side.
In my opinion it would be very hard to find a planet with the same atmospheric composition as Earth's, eg. ~21% oxygen.
But, to put it all into perspective, our current fastest probe, Voyager 1, travels at 38000 mph, to travel 20 light years it would take ~353,000 years. I think by the time they can create faster space travel (even if we can get a Generation Ship to get life to there in about 1 millenium) we will have much better candidates, or a better understanding on Gliese 581g's atmosphere.
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While Gliese 581g was hyped as a goldilocks planet a few years ago by the media, it has failed to be confirmed to exist. It was never seen directly but was only theorized to exist based upon a fluctuation in the star Gliese. While the scientists who devoted 10 years to the project were quick to make the outrageous claim that Gliese 581g was Earth2 several discrepancies later surfaced to cause doubt and suspicion on the entire project.
IF Gliese 581g does exist, it would have a revolution around Gliese of 37 days meaning the odds of it being tidally locked to its star are great. The dark side would remain completely frozen as well as much of the gasses in the atmosphere on the dark side. The lit side would receive little to no rain. That is if rain even occurs because the scientists were slow to confirm that the data showed no sign of water on the planet.
It was a botched project from the start by scientists hoping for fame and fortune.
Despite the artificial hype given to it by a gullible media, this is hardly a planet we could expect to survive on IF it even exists.
IF Gliese 581g does exist, it would have a revolution around Gliese of 37 days meaning the odds of it being tidally locked to its star are great. The dark side would remain completely frozen as well as much of the gasses in the atmosphere on the dark side. The lit side would receive little to no rain. That is if rain even occurs because the scientists were slow to confirm that the data showed no sign of water on the planet.
It was a botched project from the start by scientists hoping for fame and fortune.
Despite the artificial hype given to it by a gullible media, this is hardly a planet we could expect to survive on IF it even exists.
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Odds are none at all. It could be nothing more than a rock. It takes more than a certain amount of matter to sustain an atmosphere.