Overview
- Researchers reported in Science that high-resolution spectra taken with the Magellan Clay telescope detected helium being lost from LHS 1140 b, a rocky planet 48 light-years away.
- The team combined the helium absorption signal with physical models to show the loss rate matches a long-lived atmosphere that could have persisted for about three billion years.
- LHS 1140 b is roughly 70 percent larger than Earth and about five times more massive, and it orbits in its star’s habitable zone around a relatively old, less active red dwarf that likely helped atmosphere survival.
- The helium signal traces the planet’s extended upper atmosphere only and does not reveal lower-atmosphere composition or any signs of life, so the finding is not evidence of habitability on the surface.
- Independent repeated observations and space- and next-generation ground-based telescopes are now urgent to confirm the detection, measure the full atmospheric makeup, and assess how common long-lived atmospheres are on red-dwarf planets.