The Dense Nitrogen Atmosphere and Global Liquid Mantle of LHS 1140 b
Located approximately 48 light-years from Earth within the constellation Cetus, the planetary body known as LHS 1140 b represents one of the most significant subjects in modern observational astronomy. Orbits within the vicinity of the M-dwarf star LHS 1140 , this super-Earth has transitioned from a candidate for a rocky terrestrial world to a primary archetype for the 'Ocean World' classification. Unlike many of its counterparts in the M-dwarf systems, LHS 1140 b resides in a stable orbital configuration that has allowed for the preservation of a substantial volatile envelope, resisting the aggressive stellar winds typically associated with red dwarf stars. Its physical properties—a mass approximately 5.6 times that of Earth and a radius 1.73 times larger—suggest a composition that is far less dense than pure silicate rock, indicating a massive inventory of water or ice. Bulk Composition and the Aqueous Mantle Recent high-precision radial velocity measurements combined wi...