A planet 48 light-years away has become the first rocky world in a star’s habitable zone with a confirmed atmosphere. The planet is LHS 1140 b, a large rocky world orbiting a cool red dwarf in the constellation Cetus. The result confirms that atmospheric material is present, but it does not yet establish the composition, pressure or temperature of the air near the ground. LHS 1140 b sits in a useful but difficult middle groundLHS 1140 b is about 1.7 times Earth’s radius and roughly 5.6 times its mass. A helium-rich escape flow does not mean a person standing on LHS 1140 b would find helium-rich air.