James Webb Space Telescope Maps Uranus's Auroras in 3D
The James Webb Space Telescope has provided the first three-dimensional mapping of Uranus's auroras, offering new insights into the planet's unique magnetic field and atmospheric dynamics.
An international team of astronomers has utilized the James Webb Space Telescope (JWST) to create the first three-dimensional map of Uranus's upper atmosphere, focusing on the planet's auroras and magnetic field. The study, led by Paola Tiranti of Northumbria University, employed JWST's Near-Infrared Spectrograph (NIRSpec) to observe Uranus over nearly a full rotation, capturing the faint glow from molecules high above the cloud tops.
Uranus's magnetosphere is notably unusual, being both tilted and offset from the planet's rotation axis. This misalignment causes its auroras to sweep across the surface in complex patterns. The JWST's sensitivity allowed researchers to trace how energy moves upward through the planet's atmosphere and to observe the influence of its lopsided magnetic field.
The data also revealed that Uranus's upper atmosphere continues to cool, extending a trend observed since the early 1990s. The team measured an average temperature of approximately 426 kelvins (about 150 degrees Celsius), lower than values recorded by ground-based telescopes or previous spacecraft.
These findings enhance our understanding of the energy balance in ice giant planets and represent a significant step toward characterizing giant planets beyond our solar system.