Webb separated WASP-94A b's cloudy morning and clear evening limbs, exposing a mineral-cloud cycle and a hidden source of error in atmospheric chemistry.
WASP-94A b is too distant for the James Webb Space Telescope to photograph as a weather globe. Yet astronomers have separated two narrow slices of its atmosphere and found radically different skies. One edge is cooler and cloud-covered. The other is ... [7207 chars]