Overview
- Peer-reviewed results in Geophysical Research Letters detail the first three-dimensional map of Uranus’s ionosphere from JWST observations.
- The data show two bright auroral belts near the magnetic poles with a pronounced depletion of emissions and ion density between them.
- Ion temperatures peak roughly 4,000–5,000 kilometers above the cloud tops, while ion densities maximize near about 1,000 kilometers.
- Webb measured an average upper-atmosphere temperature near 426 K (~150°C), confirming a continued multidecade cooling.
- JWST’s NIRSpec IFU watched Uranus for about 15 hours on January 19, 2025 under GO program 5073, providing benchmarks for ice-giant energy budgets and exoplanet studies.