More planets like earth

NASA has announced that it has found seven potentially Earth-like planets orbiting a star 40 light-years away. The system is called Trappst-1. “It’s the first time that so many planets of this kind are found around a same star,” Michaël Gillon, the lead author of the Nature paper announcing the discovery, said in a press conference. “The seven planets … could have some liquid water and maybe life on the surface.”

But it’s a solar system very different from our own. For instance, Trappist-1 is a tiny, “ultra-cool” dwarf star. It’s cool because it’s small: just about a tenth of the mass of our sun and about one-thousandth as bright. But its low mass allows its planets to orbit it very closely and remain in the habitat.