Exoplanet LHS 1140b Shows Signs of a Secondary Atmosphere, Raising Questions About Habitability
Recent observations of the exoplanet LHS 1140b have detected helium escaping from its atmosphere, a significant development in the study of planets beyond our Solar System. This exoplanet, orbiting a dim red star in the constellation Cetus, is of particular interest because it is a potentially rocky world located within its star's 'habitable zone,' meaning surface temperatures could allow for liquid water. Previous observations with the James Webb Space Telescope had ruled out a hydrogen-rich 'primary' atmosphere, which typically dissipates early in a planet's life. The detection of helium now suggests the presence of a 'secondary' atmosphere, which is considered more stable and long-lived. On Earth, a secondary atmosphere has persisted for billions of years, with its chemical balance influenced by geology, chemistry, and life. While the detection of helium is a step forward, the exact nature of LHS 1140b's atmosphere and its potential for life remains uncertain, with calculations of surface conditions inv...