James Webb Telescope Detects Water Vapor on Temperate Rocky Exoplanet

A Nitrogen-Rich Secondary Atmosphere

BALTIMORE - International astrophysicists working with data from the James Webb Space Telescope announced the definitive detection of atmospheric water vapor and greenhouse gases on a temperate, Earth-sized rocky world outside our solar system.

The exoplanet, designated LHS 1140 b, orbits a calm red dwarf star located 48 light-years from Earth in the constellation Cetus. Its orbital distance places it squarely within the zone where surface liquid water can persist over geological timescales.

"This is the strongest empirical evidence yet for a secondary, volatile-rich atmosphere on a rocky planet outside our solar system," said Dr. Charles Cadieux of the University of Montreal.

Crucially, the observations ruled out a puffy hydrogen-helium envelope, indicating instead a dense, nitrogen-dominated atmosphere similar in composition to early Earth.

Follow-up transit observations scheduled for early 2027 will seek to determine surface atmospheric pressure and search for biological precursor molecules like methane and ozone.