{"data":{"id":1837,"lang":"en","title":"James Webb Telescope Maps Twin Atmospheres of Hellish Exoplanet WASP-121 b in a First","summary":"The James Webb Space Telescope has for the first time mapped distinct morning and evening atmospheres on ultra-hot exoplanet WASP-121 b, confirming theoretical predictions about tidally locked planets.","category":"science","category_label":"Science","published_at":"2026-06-15T22:02:27Z","updated_at":"2026-06-15T22:02:27Z","url":"https://techtools.cz/tools/news/article/1837-james-webb-telescope-maps-twin-atmospheres-of-hellish-exoplanet-wasp-121-b-in-a","api_url":"https://techtools.cz/news-api/v1/articles/1837?lang=en","markdown_url":"https://techtools.cz/news-api/v1/articles/1837.md?lang=en","image_url":"https://scx1.b-cdn.net/csz/news/800a/2026/from-dusk-till-dawn.jpg","word_count":210,"reading_time_minutes":2,"sources":[{"url":"https://phys.org/news/2026-06-jwst-reveals-dawn-dusk-atmosphere.html","domain":"phys.org"},{"url":"https://www.sciencedaily.com/releases/2026/06/260611024559.htm","domain":"sciencedaily.com"}],"translation":{"lang":"cs","id":1910,"title":"Teleskop Jamese Webba poprvé zmapoval dvě odlišné atmosféry pekelné exoplanety WASP-121 b","url":"https://techtools.cz/tools/news/clanek/1910-teleskop-jamese-webba-poprve-zmapoval-dve-odlisne-atmosfery-pekelne-exoplanety","api_url":"https://techtools.cz/news-api/v1/articles/1910?lang=cs"},"content":"Astronomers using the James Webb Space Telescope have made the first direct observation of dramatically different atmospheric conditions between the morning and evening sides of a distant exoplanet. Led by Cyril Gapp of the Max Planck Institute for Astronomy in Heidelberg, the team studied WASP-121 b — an ultra-hot gas giant 900 light-years from Earth — and confirmed a stark atmospheric asymmetry long predicted by theory but never directly observed.\n\nWASP-121 b is a tidally locked \"hot Jupiter,\" meaning the same face always points toward its host star. The dayside scorches at around 2,770 Kelvin (roughly 2,500°C), while the nightside sits at about 1,000 Kelvin (725°C). Powerful eastward winds carry this heat outward, expanding the evening-side atmosphere while leaving the morning side comparatively cool and compact. JWST’s infrared sensitivity let researchers track how water vapour and carbon monoxide signals shift between these two zones during a single planetary transit.\n\nThe results, published in Nature Astronomy, mark a landmark for exoplanet science: for the first time a telescope has resolved the fine longitudinal structure of an alien atmosphere down to a scale of 30 degrees of planetary rotation. Researchers say the technique opens the door to detailed climate modelling of exoplanets, potentially including worlds closer to habitable conditions."}}