An international team of astronomers, led by Paola Tiranti from Northumbria University, has for the first time observed and detailed mapped the auroras in Uranus's upper atmosphere. Thanks to fifteen hours of observations using the James Webb telescope, scientists obtained unprecedented data about the ionosphere of this ice giant. They discovered that Uranus's magnetic field is tilted by 60 degrees and the atmosphere is full of ions, leading to the formation of complex auroras. The new research also sheds light on the mystery of Uranus's cooling atmosphere, observed three decades ago.

First Observation of an Aurora

The James Webb Telescope has for the first time recorded auroras on Uranus, which are the equivalent of Earth's polar aurora. They form as a result of the interaction of charged particles with the planet's ionosphere.

Three-Dimensional Atmospheric Mapping

Scientists have created a vertical profile of Uranus's upper atmosphere, measuring temperature changes and gas abundances at different altitudes. This is the first such three-dimensional mapping of an ice giant's ionosphere.

Tilted Magnetic Field

Observations revealed that Uranus's magnetic pole is tilted by 60 degrees from the planet's rotational axis. This asymmetry causes the auroras to "sweep" across the surface in a complex manner.

Key to the Cooling Mystery

The obtained data may help explain the mechanisms behind the phenomenon of Uranus's atmosphere cooling, discovered thirty years ago, which has remained one of its greatest mysteries until now.

An international team of astronomers has made a breakthrough discovery on Uranus, utilizing the extraordinary capabilities of the James Webb Space Telescope. For the first time in history, auroras on this ice giant planet have been recorded and studied in detail, and a three-dimensional map of its upper atmosphere has been created. The observations lasted fifteen hours, corresponding to nearly a full day on Uranus, and allowed for the tracking of molecular emissions in a layer previously inaccessible to ground-based telescopes called the ionosphere. Scientists led by Paola Tiranti from Northumbria University determined that Uranus's magnetic field is significantly tilted from the planet's rotational axis, giving the auroras an exceptionally complex character. Uranus, the seventh planet from the Sun, was discovered in 1781 by William Herschel. It is classified as an ice giant, distinguished by its extreme axial tilt – the planet "rolls" along its orbit, causing unusual seasons lasting several decades. Its atmosphere, composed mainly of hydrogen, helium, and methane, has long puzzled scientists due to observational difficulties and extremely low temperatures. The new data provide a vertical profile of the atmosphere's temperature and chemical composition, which is crucial for understanding the processes occurring within it. It was discovered that Uranus's ionosphere is full of ions, and the interaction between them and the tilted magnetic field generates the auroras. It is this unique, asymmetric magnetic field, tilted by 60 degrees, that causes the auroras to "sweep" across the planet's surface in complex patterns, as explained by the study's lead, Paola Tiranti. Furthermore, the results from the James Webb observations may constitute the missing piece of the puzzle to explain the three-decade-long process of Uranus's atmosphere cooling – a phenomenon that until now lacked a satisfactory scientific explanation. This research not only expands our knowledge of the most enigmatic planet in the Solar System but also provides a new tool for studying the atmospheric physics of other worlds.

Mentioned People

  • Paola Tiranti — Researcher from Northumbria University, leading the team analyzing James Webb Telescope data regarding Uranus's atmosphere.