Life might have a shot on planets orbiting dim red stars
If exoplanets around M dwarfs host life, it’s probably very different from that on Earth
UNLIKELY WORLDS TRAPPIST-1 (illustrated) is on a growing list of dim red suns with planets that could support life. Three of its seven planets are in the habitable zone.
JPL-CALTECH/NASA
Our corner of the galaxy teems with alien worlds. In the 25 years since the discovery of the first planets beyond our solar system, astronomers have found more than 3,600 worlds orbiting other stars. A select few have become tantalizing targets in the search for life despite orbiting stars that are much smaller, cooler — and in many ways harsher — than the sun.
Just 39 light-years away, seven planets, all roughly the size of Earth, whirl around a dim red star dubbed TRAPPIST-1, astronomers announced in February (SN: 3/18/17, p. 6). Three are potentially habitable. In April, a team reported the discovery of another world snuggled up to a red sun, LHS 1140b, described by researchers at the European Southern Observatory as perhaps the best candidate in the search for signs of life. And last August, astronomers revealed that not only does a small planet named
