Astronomers searching for life beyond our solar system may need to look no farther than a little, feeble, nearby star. A Belgian-led team reported Monday that it's discovered three Earth-sized planets orbiting an ultra-cool dwarf star less than 40 light-years away. It's the first time planets have been found around this type of star—and it opens up new, rich territory in the search for extraterrestrial life. Because this star is so close and so faint, astronomers can study the atmospheres of these three temperate exoplanets and, eventually, hunt for signs of possible life. They're already making atmospheric observations, in fact, using NASA's Spitzer Space Telescope. The Hubble Space Telescope will join in next week.
Altogether, it's a "winning combination" for seeking chemical traces of life outside our solar system, says MIT researcher Julien de Wit, a co-author of the study, released by the journal Nature. The star in question—named Trappist-1 after the Belgian telescope in Chile that made the discovery—is barely the size of Jupiter and located in the constellation Aquarius. Other exoplanet searches have targeted bigger, brighter stars more like our sun, but the starlight in these cases can be so bright that it washes out the signatures of planets. By comparison, cool dwarf stars that emit infrared light, like Trappist-1, make it easier to spot potential worlds. University of Liege astronomers in Belgium built the Trappist telescope to observe 60 of the nearest ultra-cool dwarf stars and, de Wit notes, the risky effort paid off. (Read more astronomy stories.)