Helium leak confirms atmosphere on first rocky world in a habitable zone

Astronomers detected a helium signal escaping from LHS 1140 b duringtransits, providing the first atmospheric confirmation for a rocky planet in a star’s habitable zone and placing it 48 light-years away in Cetus. The finding shows an atmosphere exists, but leaves questions about its composition, pressure and surface conditions. The observation used the Magellan telescope in 2024, with a recheck in 2025 that yielded a non-detection, suggesting the escape can vary with the star’s high-energy output; further repeated helium detections and Webb observations are planned to probe the planet’s gases and potential habitability.