WASHINGTON—Astronomers have identified a quartet of small rocky planets orbiting Barnard’s star— one of our closest stellar neighbors—though they concluded that all of them are too hot to harbor life, much like our solar system’s innermost planet Mercury.
At about 6 light years away, Barnard’s star is the nearest single star—one not orbiting with other stars— to our solar system. Only the three stars in the Alpha Centauri system, about 4 light-years away, are closer. A light-year is the distance light travels in a year, 5.9 trillion miles.
