Story perspectives

JWST Finds Day-Side Clouds, Clear Nights on Hot Jupiter.

5/23/2026

Summary

Mukherjee Maps Clouds

Scientists led by Sagnick Mukherjee used JWST to map morning and evening atmospheres on WASP-94A b.
Spectroscopy showed thick magnesium-silicate clouds on the morning side and clear skies on the evening side.
Equatorial super-rotation lifts particles that condense and evaporate on the day side, revising oxygen enrichment to three-to-five times solar.
Researchers warn the bias could mislead hot-Jupiter composition estimates, while JWST saw the same cloud cycle on WASP-17b and WASP-39b.

Summary

JWST Maps Clouds

The team published a paper on April 27 2026 describing JWST data of WASP-94A b.
David Sing, Professor at Johns Hopkins, said JWST clears the view of exoplanet atmospheres.
Sagnick Mukherjee, fellow at Arizona State University, highlighted NIRISS (Near Infrared Imager and Slitless Spectrograph)’s ability to isolate limb spectra.
Using a 3-D circulation model the researchers identified a 450 K temperature gap that drives cloud formation and creates a night-side sky like Jupiter’s.

Summary

JWST Maps Weather

JWST transit-spectroscopy separated the cloudy leading-edge and clear trailing-edge atmospheric signals of WASP-94Ab.
WASP-94Ab orbits one star of a wide binary system, placing it in a dual-star environment.
The hot Jupiter completes an orbit every four days at a distance of 5.1 million miles (8.2 million km).
Researchers will apply the same weather-mapping technique to an eccentric gas giant to study how extreme temperature swings generate novel exoplanet weather patterns.

1 of 3

Mukherjee Maps Clouds

Scientists led by Sagnick Mukherjee used JWST to map morning and evening atmospheres on WASP-94A b.
Spectroscopy showed thick magnesium-silicate clouds on the morning side and clear skies on the evening side.
Equatorial super-rotation lifts particles that condense and evaporate on the day side, revising oxygen enrichment to three-to-five times solar.
Researchers warn the bias could mislead hot-Jupiter composition estimates, while JWST saw the same cloud cycle on WASP-17b and WASP-39b.

1 / 3