JWST Confirms 280-Kelvin Daily Mineral Cloud Cycle on WASP-94A b
Updated
Updated · spacedaily.com · Jul 7
JWST Confirms 280-Kelvin Daily Mineral Cloud Cycle on WASP-94A b
2 articles · Updated · spacedaily.com · Jul 7
Summary
WASP-94A b, nearly 700 light-years away, shows cloudy cooler mornings and clearer hotter evenings as mineral clouds form and evaporate within one circulation cycle.
11-sigma temperature and 6-sigma limb differences came from JWST limb-resolved transit spectroscopy, which separated the planet’s morning and evening edges instead of averaging them into one atmosphere.
The morning limb appears cloud-covered, likely with magnesium-silicate aerosols lofted near millibar pressures, while the clearer evening limb shows a 10-sigma water-vapor signal after the droplets evaporate.
That split also revised the hot Jupiter’s inferred composition, suggesting earlier Hubble-style averaged spectra can overstate heavy-element abundance by mixing distinct weather states.
The result gives exoplanet researchers a test case for reading smaller, fainter worlds, showing that clouds are part of atmospheric physics rather than just noise hiding chemistry.