Astronomers detected that the evening terminator of the ultrahot Jupiter WASP-121 b is hotter than its morning one.

WASP-121 b

Who

astronomers, Cyril Gapp, James Webb Space Telescope

What

When

Tue, 16 Jun 2026 08:08:23 GMT · 2h 40m ago

Where

WASP-121 b ·

Why

This difference was found by measuring how the planet's silhouette changed as it rotated during a single transit observed by the James Webb Space Telescope.

The Frontline Impact

How this affects you

This observation provides a new method for studying exoplanet atmospheres and weather patterns, demonstrating that a planet's rotation during a single transit can reveal atmospheric conditions and temperature asymmetries.

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Astronomers detected that the evening terminator of the ultrahot Jupiter WASP-121 b is hotter than its morning one.
Health & Science2h 40m ago
Astronomers detected that the evening terminator of exoplanet WASP-121 b is hotter than its morning one, using the James Webb Space Telescope to observe the planet's silhouette shape change during a single transit.
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Verified Sources & Citations

Space Daily
https://spacedaily.com/s-on-wasp-121-b-the-evening-sky-runs-hot-enough-to-tear-water-apart-hotter-than-the-morning-sky-and-james-webb-caught-the-difference-by-watching-the-planet-turn-during-a-single-transit/
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