JWST Observes Cold Brown Dwarf WISE 0855, Finds Water Clouds and Atmospheric Mixing

JWST spent 11 hours observing WISE 0855, a brown dwarf 7.5 light-years away with sub-zero temperatures, revealing water clouds and evidence of gas movement between atmospheric layers. This is a first detailed look at the coldest known brown dwarf, providing new constraints on substellar atmosphere models. The findings are preliminary and based on telescope data, with implications for understanding planetary atmospheres beyond our solar system.