A world 7.5 light-years away has weather — and its clouds really change

Brittany Miles, an astronomer at the University of Arizona, spent 11 hours pointing the James Webb Space Telescope at WISE 0855 — the coldest known brown dwarf, a Jupiter-sized world too small to ignite as a star. Taking a spectrum every 15 minutes, her team watched high-altitude water clouds grow thicker and thinner over time — the first time changing water clouds have ever been caught on a world beyond our solar system. Deep chemical gases churn up from below at the same time, giving scientists a new way to read weather on distant worlds. The study is accepted for publication in The Astrophysical Journal.