Astronomers have detected a helium atmosphere on the rocky exoplanet LHS 1140 b, located 48 light-years away — the first time an atmosphere has been directly confirmed on a rocky world sitting in its star's habitable zone. The planet, which has a mass 5.6 times that of Earth, orbits a small red dwarf in the constellation Cetus. "We have actually detected directly the helium present in the atmosphere itself, and that's the...