JWST Reveals Rock Clouds on WASP-94A b 700 Light-Years Away

5 articles · Updated · Scientific American · May 21

Science-published JWST observations delivered the first weather report for WASP-94A b, showing its morning edge is cloud-covered while its evening edge is largely clear.
The 4-day-orbit hot Jupiter is tidally locked, letting astronomers compare its leading and trailing limbs separately during transits and isolate starkly different atmospheric conditions.
Those clouds are thought to be vaporized rock—magnesium silicate, iron and magnesium sulfide—forming in cooler night air before burning off in morning light as winds circulate material around the planet.
The asymmetry shows exoplanet clouds can be patchy and dynamic, and suggests single, globally uniform models can misread a planet’s composition, formation and evolution.
Researchers have already applied similar JWST techniques to WASP-39 b and WASP-17 b, with future telescopes expected to extend weather studies to smaller, more Earth-like worlds.

This planet has clouds of vaporized rock. What other impossible weather is JWST about to reveal across the galaxy?

How many alien worlds have we misread by only observing their 'average' atmospheric conditions?

If a tidally locked world has a stable 'clear' zone, could this be a key factor for habitability?