Astronomers Confirm First Atmosphere on Habitable-Zone Planet

That zone, nicknamed the "Goldilocks zone" after the fairy tale, is the orbital band where a planet is neither too hot nor too cold for liquid water to persist on its surface. More than 6,000 planets are now known beyond our solar system, and hundreds sit in such zones, but only a few dozen are small and rocky, and none had shown evidence of an atmosphere. Red dwarfs are the most common type of star, yet many are violently active and strip away their planets' atmospheres. LHS 1140b, identified in 2017, has 5.6 times Earth's mass and a radius 70% larger, is tidally locked, and orbits an unusually quiet star. The helium was absent from 2025 observations, a reversal that prompted the team to re-examine its data before ruling out contamination and other false positives.

Independent researchers welcomed the result while differing on its meaning. Jayne Birkby, an astrophysicist at the University of Oxford, called it a crucial step towards understanding what it is like to live alongside a red dwarf. Yamila Miguel of Leiden Observatory was more cautious, noting that the escaping gas comes from the upper atmosphere rather than the surface layers where life would be expected to emerge, and that the results carry no direct implications for detecting life. Helium alone cannot sustain biology, though other gases may lie deeper.