First Atmosphere Detected on Rocky Habitable-Zone Planet LHS 1140b

Astronomers have confirmed the first atmosphere on a rocky planet in the habitable zone of another star, a major milestone in the search for life beyond Earth. The planet, LHS 1140 b, lies 48 light-years away and orbits a red dwarf. Using the Magellan Clay telescope in Chile, researchers detected helium escaping from the planet's upper atmosphere. The study, published in Science, provides the strongest evidence yet that a rocky world in the habitable zone can retain an atmosphere Source: BBC.

While the presence of helium alone does not support life, the team suggests heavier gases like nitrogen or carbon dioxide may exist in lower layers. The planet is 5.6 times Earth's mass and tidally locked, with one side permanently facing its star Source: Gizmodo. LHS 1140 b was discovered in 2017, and the new data from 2024-2025 allowed for atmospheric analysis. The detection technique, which uses spectral signatures of escaping helium, is now validated for future exoplanet studies Source: Wired.

Lead author Collin Cherubim of Harvard said, "This is the first time anyone has found an atmosphere on a rocky planet in the habitable zone of another star" Source: BBC. The discovery does not confirm life, but it narrows the search for Earth-like conditions elsewhere in the universe.