Thirty-nine light-years from Earth, in the ancient constellation of Cetus, astronomers have confirmed what was once only hoped for: a rocky world orbiting within its star's habitable zone does indeed carry an atmosphere. LHS 1140b, a planet heavier and wider than Earth but bathed in far less stellar warmth, has revealed helium escaping from its upper layers — a fleeting but consequential signal that air clings to worlds beyond our own. The discovery does not yet answer whether life is possible there, but it establishes that the conditions for asking that question are real.