James Webb Space Telescope Detects Atmospheric Variations Between Day and Night Sides of Ultra-Hot Exoplanet WASP-121 b

Using the James Webb Space Telescope (JWST), astronomers have discovered significant differences in atmospheric conditions between the morning and evening transition zones of the ultra-hot gas giant exoplanet WASP-121 b. The observations, published in Nature Astronomy, show variations in carbon monoxide and water signals, suggesting an asymmetry in how the planet's atmosphere absorbs infrared light from its host star. This achievement was made possible by JWST's unmatched sensitivity.