Monday, 9 April 2012
Some ”Habitable” Planets Might Not Be Habitable After All
Gliese 581c was once assumed to be a Goldilocks planet. Image courtesy of ESO.
Planets orbiting a red dwarf in the sun's habitable zone might not be habitable after all, new research suggests.
Last week, New Scientist reported on a study conducted by Rory Barnes at the University of Washington in Seattle and his colleagues.
Red dwarfs, the most common type of stars in our galaxy, are known to be unstable. As they are fainter and cooler than our sun, their habitable zones are much closer to the star.
According to New Scientist,
“Any planets orbiting in those zones feel very strong gravitational tugs from the star. Unless such a planet travels on a perfectly circular orbit, the strength of the star's pull varies at different points along its path. This squeezes and stretches the planet, heating it up.”
In other words, these planets could end up being hot like Venus.
The research suggests that some – or perhaps only one – planet system(s) seem to be designed for life.
Tides turn some habitable planets hellish. New Scientist 2859 (6 April 2012).