Overview
- A Nature Astronomy paper reports the first confirmed three-dimensional thermal map of the exoplanet WASP-18b.
- The team used spectroscopic eclipse mapping with JWST’s NIRISS instrument to reconstruct temperatures by latitude, longitude, and altitude.
- The map shows a circular dayside hotspot surrounded by a cooler ring near the planetary limbs.
- Measurements indicate reduced water vapor within the hotspot, consistent with water breaking apart under extreme heat.
- WASP-18b is an ultra-hot Jupiter about 10 times Jupiter’s mass with a 23-hour, tidally locked orbit, and researchers say additional JWST observations could sharpen maps and extend the technique to other hot Jupiters.