Exoplanet Gliese 581g tops list of potentially habitable worlds
Exoplanet Gliese 581g is back, 鈥渙fficially鈥� ranking #1 on a list of potentially habitable worlds outside of our solar system thanks to new research from the team that originally announced its discovery in 2010. Orbiting a star 20 light-years away, the super-Earth is now listed alongside other exoplanets聽Gliese 667Cc, Kepler-22b, HD85512 and Gliese 581d in the University of Puerto Rico at Arecibo鈥檚听聽as good places to look for Earthlike environments鈥� and thus the possibility of life.
First announced in September 2010 by a team led by聽Steven S. Vogt of UC Santa Cruz, the presence of Gliese 581g was immediately challenged by other astronomers whose data didn鈥檛 support its existence. Vogt鈥檚 team conducted further analysis of the Gliese system in which it appeared that the orbits of the planets were circular, rather than elliptical, and it was in this type of scenario that a strong signal for Gliese 581g once again appeared.
鈥淭his signal has a False Alarm Probability of < 4% and is consistent with a planet of minimum mass 2.2M [Earth masses], orbiting squarely in the star鈥檚 Habitable Zone at 0.13 AU, where liquid water on planetary surfaces is a distinct possibility鈥� said Vogt.
And, located near the center of its star鈥檚 habitable 鈥淕oldilocks鈥� zone and receiving about the same relative amount of light as Earth does, Gliese 581 g isn鈥檛 just聽on聽the list鈥� it鈥檚 now considered the聽best聽candidate for being an Earthlike world 鈥� knocking previous favorite Gliese 667Cc into second place.
The announcement was made on the聽聽earlier today by Professor聽Abel M茅ndez, Director of the PHL at UPR Arecibo.
Diagram of the Gliese system. The green area is the habitable zone, where liquid water can exist on a planet鈥檚 surface. (PHL @ UPR Arecibo)
鈥淭he controversy around Gliese 581g will continue and we decided to include it to our main catalog based on the new significant evidence presented, and until more is known about the architecture of this interesting stellar system鈥�
鈥� Prof. Abel聽M茅ndez, UPR Arecibo
Jason Major is a graphic artist from Rhode Island now living and working in Dallas, Texas. He writes about astronomy and space exploration on his blog聽, on Universe Today and also on Discovery News.
This story originally appeared in .
