James Webb Space Telescope forecasts extreme weather on exoplanet that rains rubies and sapphires

An illustration of a bright star toward the left top of the image. There is a pinkish, slightly stretched-out exoplanet toward the center-right-lower area.

Imagine a world where the weather forecast calls for winds blowing at 11,000 miles per hour (18,000 kilometers per hour) and nighttime showers of liquid metal, rubies and sapphires.

This is the chaotic reality astronomers have pieced together for WASP-121b, an "ultra-hot Jupiter" that ranks among the most extreme planets known beyond the solar system.