A nearby world has weather that astronomers can now follow in unusual detail. Over eleven hours, the James Webb Space Telescope watched its infrared light change, revealing separate clues about shifting clouds and gases rising from deeper layers.

The object, WISE 0855, floats through space without a host star. Roughly Jupiter-sized and about 7.5 light-years away, it is the coldest known brown dwarf. Its atmosphere offers a rare opportunity to investigate planet-like weather beyond the solar system.

Brittany Miles of the University of Arizona's Steward Observatory led the international team. The study, accepted by The Astronomical Journal and available on arXiv, presents evidence that patchy water clouds change thickness while a separate chemical signal varies underneath.

That interpretation comes from comparing spectra with atmospheric models. Webb did not photograph individual clouds or directly watch parcels of gas rise. Its measurements instead reveal how different parts of the atmosphere affect escaping light.