Earth-like exoplanet LHS 1140b found to have atmosphere, researchers say
7 reported2 unconfirmed
Researchers have announced the discovery of an atmosphere around LHS 1140b, an Earth-like planet 49 light years away that could have liquid water on its surface. Dr Collin Cherubim, the first author of the study, said this is the first observationally confirmed atmosphere on a rocky planet in the habitable zone outside our solar system. The planet, discovered in 2017, has a mass 5.6 times that of Earth and a radius 70% larger. It orbits a small red dwarf in the constellation of Cetus. The team used an infrared spectrograph on the Magellan Clay telescope in Chile, capturing data in 2024 that revealed escaping helium. No atmosphere was found around LHS 1140c, another rocky planet orbiting the same star. The findings were published in the journal Science.
What’s reported
LHS 1140b is 49 light years away and was discovered in 2017.
It has a mass 5.6 times Earth’s and a radius 70% larger.
The planet is tidally locked and could have far more water than Earth.
Data from 2024 showed helium escaping from the planet’s upper atmosphere.
Helium was not detected in 2025 observations, which Cherubim described as a shock.
The team ruled out other explanations for the helium signal, including Earth’s atmosphere contamination.
No atmosphere was found around LHS 1140c.
Open questions
Why helium was detected in 2024 but not in 2025.
Whether the atmosphere contains other gases or could support life.
Key figures
Dr Collin Cherubim, first author of the study, formerly at Harvard University.
Jayne Birkby, professor of astrophysics at the University of Oxford.
Dr Yamila Miguel of Leiden Observatory in the Netherlands.
Sources: The Guardian
