An international team of astronomers has announced the detection of an atmosphere surrounding LHS 1140b, an Earth-like exoplanet located 49 light-years from Earth. This represents a significant milestone in exoplanet research, as it marks the first observationally confirmed atmosphere on a rocky planet within a habitable zone outside the solar system, and the first direct identification of an atmospheric species on any rocky exoplanet.
LHS 1140b was originally discovered in 2017 and orbits a small red dwarf star in the constellation Cetus. The planet has a mass approximately 5.6 times that of Earth and a radius about 70% larger. Researchers used an infrared spectrograph mounted on the Magellan Clay telescope at Las Campanas Observatory in Chile to observe the planet as it passed in front of its host star. Data collected in 2024 revealed the presence of helium escaping from the planet’s atmosphere into space. The findings have been published in the journal Science.
According to study lead Dr. Collin Cherubim, the discovery is particularly significant because LHS 1140b possesses the key requirements for habitability: a rocky composition, temperatures suitable for liquid water, an atmosphere capable of retaining water and shielding against harmful radiation, and a relatively quiet host star with minimal flare activity. However, subsequent observations made in 2025 did not detect helium, prompting the research team to conduct extensive verification to rule out false positives and atmospheric contamination from Earth.
The discovery carries implications for understanding planetary atmospheres around red dwarf stars, which are the most common type of star in the galaxy. External experts noted that red dwarfs typically emit high levels of ultraviolet radiation that can strip away planetary atmospheres, making the detection of an atmosphere around LHS 1140b particularly noteworthy. Some researchers cautioned, however, that the observed helium signals originated from the upper atmosphere rather than regions near the surface where life might potentially exist, limiting direct implications for detecting biological signatures on other worlds.
Article Attribution | Read More at Article Source
Article summary produced by Claude AI