US astronomers track Earth-like cloud changes on world 7.5 light-years away

What happened

US astronomers track Earth-like cloud changes on world 7.5 light-years away, according to Interesting Engineering. Water clouds are growing thicker and thinner on a frigid world just 7.5 light-years from Earth, giving astronomers a direct view of changing weather beyond the solar system. A team led by Brittany Miles at the University of Arizona’s Steward Observatory used the James Webb Space Telescope to observe WISE 0855, the coldest known brown dwarf, for 11 hours.

Collecting a spectrum every 15 minutes, the researchers distinguished shifting cloud cover from gases rising out of deeper atmospheric layers. Watching water clouds change WISE 0855 sits near the boundary between brown dwarfs and giant planets.

Brown dwarfs lack sufficient mass to ignite as stars and instead emit faint light from heat left over after their formation. At about twice Jupiter’s mass and nearly the same size, WISE 0855 resembles a free-floating giant planet.