WASP-17b exoplanet atmospheric profile mapped using new technique

Astronomers have successfully mapped the three-dimensional atmospheric profile of the exoplanet WASP-17b, revealing a highly asymmetrical structure. Using data from the James Webb Space Telescope (JWST), researchers applied a new technique known as ‘transmission strings’ to analyze light passing through different sections of the planet's atmospheric limb.

Unlike traditional methods that average the entire planetary edge, this approach allows scientists to distinguish between different regions, such as the morning and evening sides, as well as the equator and poles. The study found that the atmosphere on the evening side is significantly warmer and more expanded than on the morning side, with an estimated temperature difference of approximately 660K. This asymmetry is driven by powerful equatorial winds that transport heat from the day side to the night side.

The findings, published in Nature Astronomy, demonstrate that the chemical composition and temperature of WASP-17b vary significantly by latitude and longitude. This technological breakthrough enables future studies to map specific weather phenomena, such as hurricanes and cyclones, on distant worlds.