Webb Discovers Methane, Carbon Dioxide in Atmosphere of K2-18 b - NASA

A new investigation with NASA’s James Webb Space Telescope into K2-18 b, an exoplanet 8.6 times as massive as Earth, has revealed the presence of carbon-bearing molecules including methane and carbon dioxide. Webb’s discovery adds to recent studies suggesting that K2-18 b could be a Hycean exoplanet, one which has the potential to possess a hydrogen-rich atmosphere and a water ocean-covered surface.Download the full-resolution, uncompressed version and supporting visuals from the Space Telescope Science Institute.The first insight into the atmospheric properties of this habitable-zone exoplanet came fromobservations with NASA’s Hubble Space Telescope, which prompted further studies that have since changed our understanding of the system.K2-18 b orbits the cool dwarf star K2-18 in thehabitable zoneand lies 120 light-years from Earth in the constellation Leo. Exoplanets such as K2-18 b, which have sizes between those of Earth and Neptune, are unlike anything in our solar system. This lac...