Space: New Details About a Hellish Planet Where It Rains Liquid Metal, Sapphires, and Rubies

The James Webb Space Telescope (JWST) has provided new details about one of the most hostile worlds discovered so far. It is the gas giant exoplanet WASP-121b, an "ultra-hot Jupiter” located so close to its star that a year lasts just over 30 hours. According to a study published in the journal Nature Astronomy, this planet's atmosphere is crossed by winds at speeds of about 18,000 km/h, and the temperatures are so high that they vaporize metals, which then condense and fall in the form of exotic rain on the dark side of the planet.

• A planet deformed by the star's gravity

WASP-121b orbits the star WASP-121 at the limit at which gravitational forces could begin to disintegrate it. These huge tidal forces have deformed the planet, which is no longer spherical, but has an elongated shape, similar to a rugby ball, informs space.com. The planet is gravitationally locked, so that the same hemisphere is always oriented towards the star and is in continuous light, while the other side remains in perpetual night.

• Metals evaporate and fall as rain

On the lighted side, temperatures are so high that they vaporize elements such as iron and magnesium. These are carried by atmospheric currents to the colder, darker side, where they condense and fall as precipitation. Previous observations made with the Hubble Space Telescope have shown that iron and magnesium escape from the planet's atmosphere itself, pushed by the intense ultraviolet radiation of the host star.

The researchers, led by Cyril Gapp, of the Max Planck Institute for Astronomy in Germany, used the unprecedented sensitivity of the James Webb Telescope to analyze the planet's atmosphere as it rotates. "With unprecedented observational quality, JWST is providing us with the most detailed images of distant planets to date," said the researcher. The analysis showed that the "evening" region, which leaves the illuminated side, is hotter than the "morning" region, which enters the light. The difference is explained by extremely strong winds that carry heat from the incandescent hemisphere to the dark one.

• Possible mineral clouds

The data collected indicated variations in the concentrations of water vapor and carbon monoxide. On the hotter side, temperatures appear high enough to break down water molecules in the upper layers of the atmosphere. On the cooler side, on the other hand, there could be clouds made of silicates and other minerals, although the researchers emphasize that more complex models are needed to confirm this hypothesis.

The results complement previous observations made with the Very Large Telescope in Chile, which highlighted the existence of jet streams and complex atmospheric structures that extend over half of the planet. The new method used by the international team could be applied to other ultra-hot exoplanets, giving astronomers the opportunity to compare atmospheric phenomena on worlds hundreds of light-years away.