Friday, March 30, 2012

Billion of Planets


This artist's impression shows a sunset seen from the super-Earth Gliese 667 Cc.

"The Creator must have an inordinate fondness for beetles," the early 20th-century biologist J.B.S. Haldane once said. "He made so many of them." If Haldane had been an astronomer, he might have said the same about the nondescript red stars known as M-dwarfs. As the name implies, they're small, no more than half the size of our Sun at most. They're so dim that not a single one, not even the closest, is visible to the naked eye. And they vastly outnumber any other type of star in the Milky Way: our galaxy has maybe ten or 20 billion Sun-like G stars, but is home to 150 billion M-dwarfs, and maybe more, adding up to some 80% of the galaxy's stellar population./.../

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