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Health & Science4h 18m ago

James Webb Space Telescope observations suggest that the two day-night boundary zones on the gas exoplanet WASP-121 b are chemically different from each other.

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WASP-121 b

Who
Astronomers, Cyril Gapp, Tom Evans
What
James Webb Space Telescope observations suggest that the two day-night boundary zones on the gas exoplanet WASP-121 b are chemically different from each other.
When
Tue, 16 Jun 2026 05:28:00 GMT · 4h 18m ago
Where
WASP-121 b ·
Why
This study offers the clearest evidence so far that an exoplanet's sunrise and sunset regions might not share the same temperatures or chemical makeup.
The Frontline Impact

How this affects you

The finding gives researchers an unusually detailed view of how weather and atmospheric circulation work on a tidally locked exoplanet and a better way to build three-dimensional maps of alien atmospheres.

Story chain

4 events in this thread
  1. Health & Science1h 38m ago
    Astronomers detected that the evening terminator of the exoplanet WASP-121 b is hotter than its morning one, a first-time measurement achieved by observing the planet's rotation during a single transit with the James Webb Space Telescope.
    Open article
  2. Health & Science1h 38m ago
    Astronomers watched the ultrahot Jupiter WASP-121 b cross its star and detected, for the first time, that its evening terminator is hotter than its morning one, by measuring how the planet's silhouette changed as it rotated during the transit.
    Open article
  3. Currently Reading4h 18m ago
    James Webb Space Telescope observations suggest that the two day-night boundary zones on the gas exoplanet WASP-121 b are chemically different from each other.
  4. Health & Science4h 18m ago
    JWST observations suggest that the two day-night boundary zones on the gas exoplanet WASP-121 b are chemically different from each other.
    Open article

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