JWST spots salt-cloud haze in the Pink Planet's cold atmosphere

The James Webb Space Telescope has for the first time obtained a spectrum of GJ 504 b, the so-called Pink Planet, showing its light is best explained by a hazy atmosphere with salt clouds. The analysis detects water vapor, CO, methane, CO2, ammonia and hydrogen sulfide, plus signs of metal enrichment and disequilibrium chemistry, suggesting a dynamic, cloud-forming atmosphere. The planet is extremely cold for a directly imaged world (about 564 K) and sits near the planetary-mass/brown-dwarf boundary; the salt-cloud model is the key to fitting the spectrum, though the object's exact nature remains unsettled. The result demonstrates JWST’s ability to study faint, cold exoplanets and tests cloud-formation theories long discussed in theoretical work.