James Webb maps first daily weather cycle on an exoplanet

Added: 2026-06-01

[00:00:00]On a planet 700 light-years away, every morning brings clouds of vaporized rock that vanish by sunset.

[00:00:08]A team led by Johns Hopkins University used the James Webb Space Telescope to map the daily weather on WASP-94ab, a giant gas planet about the size of Jupiter.

[00:00:22]The planet is tidally locked to its star, so one side is always in daylight and the other in constant night.

[00:00:30]Web found thick clouds of magnesium silicate on its morning side. That is essentially vaporized rock.

[00:00:38]The clouds form on the cooler night side, then strong winds push them into the day side, where the intense heat makes them evaporate.

[00:00:47]By the evening side, the sky is clear.

[00:00:51]The discovery is the first daily weather cycle ever mapped on an exoplanet.

[00:00:57]It also exposes a long-standing error in how scientists have been reading exoplanet atmospheres for years.