Exoplanet Gliese 581d Could Support Life
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According to a recent article in The Astrophysical Journal, researchers Wordsworth, Forget, et al. claim that famed exoplanet Gliese 581d, could in fact be a habitable planet, despite the fact the planet receives about 1/3 less energy than Mars, and is probably locked in tidal resonance ( one side of the planet always faces its host star).
Illustration of Our Sun ( left ) and Gliese 581 (right). Photo Credit: Wikimedia Commons / RJHall
The Gliese 581 star system is about twenty light years away, in the constellation Libra. The system has at least four and possibly six or more planets. Gliese 581 is a “red-dwarf” BY Draconis variable class star, about 1/3 the mass and radius of our Sun and is estimated to be roughly 7 to 11 billion years old.
Utilizing three dimensional climate simulations, the team has been able to demonstrate that the super-Earth (2-10 times the mass of Earth) could have a stable atmosphere and liquid water for a number of plausible conditions. Based on the cases demonstrated in the article, the claim has been made that GJ581d is the first confirmed super-Earth in the habitable zone of its parent star.
The team has found that atmospheres with over 10 bar ( Earth’s atmosphere at sea-level is slightly over 1 bar) of CO2 and different amounts of other gases, such as Nitrogen can result in planet-wide temperatures over 0°C for both land and ocean-covered surfaces. Using the Infra-red emissions calculated by their model, the team has proposed observational tests that distinguish the cases presented by said model from other possible scenarios in the future.
If you would like to read the full journal article, you can purchase a copy from The Astrophysical Journal at:
http://iopscience.iop.org/2041-8205/733/2/L48/fulltext
Source:The Astrophysical Journal Letters – Number 2, 2011 June 1
Ray Sanders is a Sci-Fi geek, astronomer and blogger. Currently researching variable stars at Arizona State University, he writes for Universe Today, The Planetary Society blog, and his own blog, Dear Astronomer
2012-12-04 08:06:02
Source: http://www.dearastronomer.com/2011/05/17/exoplanet-gliese-581d-could-support-life/
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