JWST maps Uranus's upper atmosphere in 3D, revealing auroras and magnetic quirks

Using JWST's NIRSpec, an international team mapped Uranus's upper atmosphere in 3D for the first time, detailing how temperature and ion density vary up to 5,000 km above the clouds. The study finds peak temperatures around 3,000–4,000 km and ion-density maxima near 1,000 km, with two bright auroral bands and a magnetic-field driven depletion region. The average upper-atmosphere temperature is about 426 K (roughly 150 C), and the atmosphere continues to cool since the 1990s, offering new insight into the energy balance of ice giants.