Astronomers detect first atmosphere on a rocky, habitable-zone exoplanet

Harvard-led researchers, publishing in Science, report the first atmosphere ever detected around a rocky, Earth-sized planet sitting in its star’s habitable zone. The world, LHS 1140 b, lies 48 light-years away and orbits a small, cool red star at a distance where liquid water could theoretically exist — the so-called Goldilocks zone. Of the 6,000-plus known exoplanets, only a few dozen are both small and rocky like Earth and positioned in that zone, and none had shown an atmosphere until now.

The catch: the only gas identified so far is helium, likely confined to the upper atmosphere, which cannot sustain life on its own. Researchers suspect more biologically relevant gases may sit lower down, but that remains unconfirmed. Lead author Collin Cherubim and co-author David Charbonneau frame the significance not as evidence of life but as the first proof that an Earth-like planet elsewhere can hold onto an atmosphere at all — a prerequisite for habitability.

The finding lands amid a run of cautious results elsewhere in the field. A 2025 NASA reanalysis downgraded the much-hyped dimethyl sulphide signal on the sub-Neptune K2-18b, showing the gas can form without biology. Among the TRAPPIST-1 system’s seven rocky worlds, the James Webb telescope has ruled out an Earth-like atmosphere on TRAPPIST-1d, while TRAPPIST-1e stays inconclusive. LHS 1140 b now stands out as the strongest atmospheric candidate to date.