James Webb detects strong winds on the planet "The Two-Faced God"

Using the James Webb Space Telescope, scientists have mapped the weather on a planet 280 light-years from Earth, a hot gas giant with one side permanently facing its sun and the other covered in eternal night.

The planet, called WASP-43b, is composed primarily of hydrogen and helium and is much hotter than any gas giant in our solar system, due to its proximity to its host star, which it orbits once every 19 Earth hours. This close proximity means that WASP-43b is tidally locked to its star.

Scientists have now discovered that this tidal locking permanently heats one side of the planet to temperatures of about 2,300 degrees Fahrenheit (1,260 degrees Celsius), hot enough to melt iron. This scorching heat vaporizes the rocks and carries them into the clouds.

Scientists found that the temperature difference between day and night, which is relatively colder at 1,110 F (600 C), results in strong winds that can reach speeds of up to 5,600 mph (9,000 km/h).

WASP-43b, which is described as the planet Janus, the two-faced god in Roman mythology, was discovered in 2011. It was initially studied by the Hubble and Spitzer telescopes, but James Webb's super-resolution has now captured the finer details of its atmosphere.

“With Hubble, we can clearly see that there is water vapor on the dayside,” says lead author of the study published in the journal Nature Astronomy, Taylor Bell, a researcher at the Bay Area Environmental Research Institute in San Jose, California. “Both Hubble and Spitzer suggested that it might "There will be clouds on the night side, but we needed more precise measurements from James Webb to actually start mapping the temperature, cloud cover, winds and atmospheric composition in more detail all the way around the planet."

To measure the planet's temperature, researchers used James Webb's mid-infrared instrument (MIRI) to measure light from the system every 10 seconds for more than 24 hours.

Taylor added: "By observing an entire orbit, we were able to calculate the temperature of the different sides of the planet as they orbited the horizon. From that, we could build a rough map of the temperature across the planet."

Infrared measurements by the James Webb Space Telescope also revealed the planet's chemical composition, which includes water vapor but lacks methane.