Astronomers Confirm Atmosphere on Rocky Planet in Habitable Zone

Scientists have detected an atmosphere around a rocky Earth-like planet located 49 light years away, marking the first confirmed atmosphere on a rocky planet in the habitable zone outside our solar system. The planet, named LHS 1140b, could have liquid water on its surface, according to a study published recently.

While atmospheres have been observed on gas giants and sub-Neptunes, and signs of atmospheres have been found on rocky exoplanets outside their star's habitable zone, this is the first time an atmosphere has been confirmed on a rocky planet within the habitable zone—the region where liquid water could exist.

Dr Collin Cherubim, the study's lead author, formerly of Harvard University, said the findings are the first direct identification of an atmospheric species for any rocky exoplanet, whether in a habitable zone or not. He described the discovery as a major step in studying astrobiology and habitability beyond our solar system.

LHS 1140b has a mass 5.6 times that of Earth and a radius 70 percent larger. The planet is tidally locked, meaning one side always faces its star, and likely has a different atmosphere composition compared to Earth. It orbits a small red dwarf star in the constellation Cetus.

Dr Cherubim noted that the planet has all the ingredients for a habitable environment: a rocky composition, a temperature that supports liquid water, and an atmosphere that can prevent water loss and protect against harmful radiation. The star is also relatively calm, with few flares.

LHS 1140b was first discovered in 2017. Its proximity and characteristics make it a prime candidate for further study of planetary habitability.