With a ‘tumbling’ magnetic field, an influx of solar wind, and a magnetosphere that behaves like a light switch, the conditions around Uranus are somewhat of a ‘nightmare.’

A new study analyzing data collected more than 30 years ago by the Voyager 2 spacecraft has found that the ice giant’s global magnetosphere is nothing like Earth’s, which is known to be aligned nearly with our planet’s spin axis.

Numerical simulations revealed that, instead of opening and closing in response to solar wind as Earth’s does, Uranus’ lopsided magnetosphere flips ‘on’ and ‘off’ on a daily basis as the planet moves through its 17.24-hour rotation.

Reconnection can be seen all throughout the solar system, and even plays a role for Earth’s stunning auroras. According to the researchers, auroras can be seen on Uranus as well at all at various latitudes (as seen as the white splotches above)

WHAT THEY FOUND Uranus lies and rotates on its side, leaving its magnetic field tilted 60 degrees from its axis. As a result, the magnetic field ‘tumbles’ asymmetrically relative to the solar wind. As a result, the magnetic field ‘tumbles’ asymmetrically relative to the solar wind. When the magnetosphere is open, it allows solar wind to flow in. But, when it closes off, it creates a shield against these particles. The researchers suspect solar wind reconnection takes place upstream of Uranus’s magnetosphere at different latitudes, causing magnetic flux to close in various parts. Advertisement

‘Uranus is a geometric nightmare,’ said Carol Paty, a Georgia Tech associate professor and co-author of the study.

‘The magnetic field tumbles very fast, like a child cartwheeling down a hill head over heels.

‘When the magnetized solar wind meets this tumbling field in the right way, it can reconnect and Uranus’ magnetosphere goes from open to closed to open on a daily basis.’

According to the researchers from Georgia Institute of Technology, this behaviour is vastly different from what’s seen around Earth.

Earth’s magnetosphere spins with the planet’s rotation – and, as it always faces toward the sun, the field typically only opens and closes in response to changes in solar wind, such as in the case of strong solar storms.

Uranus, on the other hand, lies and rotates on its side, leaving its magnetic field tilted 60 degrees from its axis.

As a result, the magnetic field ‘tumbles’ asymmetrically relative to the solar wind.

When the magnetosphere is open, it allows solar wind to flow in. But, when it closes off, it creates a shield against these particles.

The researchers suspect solar wind reconnection takes place upstream of Uranus’s magnetosphere at different latitudes, causing magnetic flux to close in various parts.

Reconnection can be seen all throughout the solar system, and even plays a role for Earth’s stunning auroras.

With a ‘tumbling’ magnetic field, an influx of solar wind, and a magnetosphere that behaves like a light switch, the conditions around Uranus (pictured) are somewhat of a ‘nightmare’

According to the researchers, auroras can be seen on Uranus as well, at various latitudes.

But, being roughly 2 billion miles away from Earth, they’re more difficult to observe.

‘The majority of exoplanets that have been discovered appear to also be ice giants in size,’ said Xin Cao, the Georgia Tech PhD candidate in earth and atmospheric sciences who led the study.

‘Perhaps what we see on Uranus and Neptune is the norm for planets: very unique magnetospheres and less-aligned magnetic fields.

‘Understanding how these complex magnetospheres shield exoplanets from stellar radiation is of key importance for studying the habitability of these newly discovered worlds.’