Study indicates existence of billions of habitable alien planets in Milky Way (+video)
A survey of red dwarf stars suggests that, in our galaxy alone, there are tens of billions of planets orbiting their stars' 'habitable zones.'
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The two stars found inside the habitable zone were discovered around the stars Gliese 581 and Gliese 667 C. The latter planet is the second of three worlds orbiting its star, and seems to lie right in the middle of Gliese 667 C's habitable zone. Although the planet has four times the mass of Earth, it is considered the closest twin to Earth found so far.Skip to next paragraph
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Search for life
This and other planets are good candidates for follow-up studies that aim to analyze the atmospheres of these worlds for signs that organisms are living there.
"Now that we know that there are many super-Earths around nearby red dwarfs, we need to identify more of them using both HARPS and future instruments," said team member Xavier Delfosse. "Some of these planets are expected to pass in front of their parent star as they orbit — this will open up the exciting possibility of studying the planet's atmosphere and searching for signs of life."
However, there are some issues with looking for life around red dwarfs.
Since these stars are cooler than the sun, their habitable zones are much closer in than ours. That puts any planets there at risk of being hit with stellar eruptions or flares, which are common on red dwarfs. Such flares could release X-rays or ultraviolet radiation that could harm or inhibit the development of life, scientists say.
The new findings will be described in a paper to be published in an upcoming issue of the journal Astronomy & Astrophysics.
You can follow SPACE.com assistant managing editor Clara Moskowitz on Twitter @ClaraMoskowitz. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.
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