Researchers have reported the first detected atmosphere around a rocky, Earth-like planet orbiting in another star’s habitable zone. The planet, LHS 1140 b, lies 48 light-years from Earth and circles a red star that is smaller and cooler than the Sun.
The gas identified so far is helium, probably high in the atmosphere. Helium alone cannot support life, and the researchers did not claim to have found biology. The significance is instead that a small rocky world at a potentially temperate distance from its star has retained an atmosphere that astronomers can begin to characterize. The work was reported in the journal Science, according to the BBC.
A habitable zone describes the range of orbital distances where temperatures may allow liquid water, assuming other planetary conditions cooperate. Astronomers have found hundreds of planets in these zones, but only a few dozen are both small and rocky. Before this result, none of those worlds had a confirmed atmosphere, the researchers said.
Harvard researcher Collin Cherubim, the study’s lead author, called the detection an important first. His colleague David Charbonneau said it advances the broader effort to determine whether life exists beyond Earth and the Solar System. The next question is whether gases more relevant to habitability exist lower in LHS 1140 b’s atmosphere. The current helium signal cannot answer that.
The finding sits alongside several other closely watched systems. K2-18 b, a larger sub-Neptune that may have a water-rich interior, drew attention over a possible dimethyl sulphide signal. A NASA-led reanalysis in 2025 found that signal too weak to confirm and noted that the gas can arise without biology. In the TRAPPIST-1 system, observations by the James Webb Space Telescope ruled out an Earth-like atmosphere for TRAPPIST-1 d, while evidence for TRAPPIST-1 e remained inconclusive.
Those examples illustrate why atmospheric detection and evidence of life must be kept separate. Finding gas around LHS 1140 b gives researchers a new target and demonstrates that atmospheric study is possible for a particularly valuable class of planet. Establishing surface conditions, identifying additional molecules and excluding non-biological explanations will require further observation. For now, the result expands the known environments in which the search can proceed without resolving whether any distant world is inhabited.
