First Atmosphere Confirmed on a Rocky Exoplanet in a Habitable Zone

• Astronomers have confirmed an atmosphere around LHS 1140 b, a rocky exoplanet located 48 light-years away in the habitable zone of a red dwarf star.
• The discovery, led by Collin Cherubim of Harvard University, represents the first time an atmosphere has been identified on a potentially habitable-zone rocky world.
• Researchers used mathematical modeling to predict a helium-rich atmosphere before verifying it with the WINERED spectrograph on the Magellan Telescope in Chile.

The Discovery and Methodology

• LHS 1140 b orbits within its star's habitable zone, where temperatures could allow for liquid water.
• Mathematical predictions suggested an upper atmosphere leaking helium into space, a theory later confirmed by transit observations.
• Observations were validated by a rare alignment where LHS 1140 b and a neighboring planet transited their host star simultaneously, allowing for a clear comparative analysis.
• The data indicates the atmosphere has persisted for over three billion years.

Scientific Significance

• The study, published in the journal Science, moves beyond the search for habitable-zone candidates to verifying if they possess the necessary gas layers for weather, radiation protection, and potential chemistry.
• The success of the prediction-led methodology provides a new framework for investigating other rocky exoplanets.
• Future research aims to characterize the composition of the atmosphere further and assess the possibility of surface oceans.