James Webb created the first three‑dimensional map of auroras on Uranus, where they are visible even at the equator.

James Webb Space Telescope first creates a 3‑D map of Uranus’s aurorae

An international team of astronomers used the Webb telescope to observe the distant planet for nearly an entire rotation period (≈ 17 h). This provided unique spectral data on the upper layers of its atmosphere up to several thousand kilometers above the clouds, allowing a more precise understanding of Uranus’s structure.

Why Uranian aurorae are unusual
Uranus’s magnetic field is strongly tilted from its spin axis—about 60°, compared with Earth’s ≈ 11°. This “desynchronization” causes aurorae to appear even at equatorial latitudes. Thanks to Webb, all such phenomena were recorded for the first time within a single day, marking a historic achievement.

What the study revealed
- Two bright bands near the magnetic poles.
- A zone of low emission and ion density between them.
- Heating in auroral regions is limited: temperatures rise only by a few tens of degrees.

These observations demonstrate the complex interaction between the magnetosphere and atmosphere, and confirm the ongoing cooling of the upper layers. Since the first temperature measurement of Uranus, it has been gradually dropping—now we see this in three dimensions.

How aurorae form
Solar wind ionizes atmospheric atoms; excited atoms later return to their ground state, emitting photons. This allows study of composition, dynamics, and energy distribution in the atmosphere.

Significance of the discovery
The results surpass those of earlier missions such as Voyager‑2. Scientists call it a breakthrough:

> “This is the first time we have been able to see Uranus’s upper atmosphere in three dimensions,” said project leader Paola Tiranti (Northumbria University).

The data open new prospects for understanding the physics of ice giants, their magnetospheres, and aurorae. This is important not only for studying planets in our Solar System but also for interpreting processes on exoplanets in distant corners of the Universe.