Overview
- An international team led by Paola Tiranti traced H3+ with JWST’s NIRSpec Integral Field Unit across nearly a full Uranian rotation.
- General Observer program 5073, led by Henrik Melin, monitored Uranus for about 15 hours on January 19, 2025 to build the dataset.
- Webb mapped two bright auroral bands near the magnetic poles separated by a narrow depleted zone shaped by the planet’s tilted, offset magnetic field.
- The vertical structure shows temperatures peaking around 3,000–4,000 kilometers, ion densities maximizing near 1,000 kilometers, and emissions detected up to roughly 5,000 kilometers above the clouds.
- Average upper-atmosphere temperatures measured about 426 kelvins (near 150°C), extending a decades-long cooling trend reported in the peer-reviewed study in Geophysical Research Letters.