Exoplanet K2-18 b lies in the habitable zone of its host star some 110 light-years from Earth. In a major first, scientists have detected water vapor and possibly even liquid water clouds that rain in the atmosphere of a strange exoplanet that lies in the habitable zone of its host star about 110 light-years from Earth. A new study focuses on K2-18 b, an exoplanet discovered in 2015, orbits a red dwarf star close enough to receive about the same amount of radiation from its star as Earth does from our sun. Previously, scientists have discovered gas giants that have...