Observing with the James Webb Space Telescope
An international team pointed the James Webb Space Telescope at a tidally locked hot Jupiter to capture its infrared emission. The data show that the side permanently facing its host star is blazingly hot, while the opposite hemisphere remains considerably cooler.
The temperature contrast between the two hemispheres reaches several hundred kelvins. On the scorching side, a thick, turbulent atmosphere hosts winds that can exceed several kilometres per second. These fierce currents are energetic enough to break apart water molecules and drive exotic chemistry.
The findings suggest that current exoplanet atmospheric models are missing a key physical ingredient. The interplay of extreme heating, supersonic winds, and rapid chemical reactions is not fully reproduced in simulations, leading to mismatches between predicted and observed spectra.
Future observations with JWST and complementary facilities aim to pinpoint the atmospheric composition and vertical wind structure with higher precision. Refining these measurements should help close the gaps in theory and improve our grasp of weather dynamics on distant worlds.