Hubble Captures Stunning Images of Saturn's Auroras Created by Collapsing Magnetotail

Scientists have captured new, stunning images of Saturn's auroras as the planet's magnetic field is battered by charged particles from the sun. The findings may actually help prove the theory that Saturn's auroras are often caused by the dramatic collapse of its "magnetic tail."

In this case, the scientists captured ultraviolet images with Hubble's Advanced Camera for Surveys. They caught the moment when Saturn's magnetic field was affected by bursts of particles streaming from the sun.

Rather like a comet, planets like Saturn and Earth have a "tail," known as a magnetotail. This magnetotail is made up of electrified gas from the sun and flows outward in the planet's wake as it orbits. When a strong burst of particles from the sun hits Saturn, it can cause the magnotail to collapse, and the ensuing disturbance can wreak havoc on the planet's magnetic field and result in auroras.

That's exactly what the scientists caught in action in these new images. You can see the auroras shining brightly in the ultraviolet range of the electromagnetic spectrum. Some of the bursts of light seen shooting around Saturn's polar regions travelled at over three times faster than the speed of the gas giant's rotation.

"These images are spectacular and dynamic, because the auroras are jumping around so quickly," said Jonathan Nichols, one of the researchers, in a news release. "The key difference about this work is that it is the first time the Hubble has been able to see the northern auroras so clearly. The particular pattern of auroras that we saw relates to the collapsing of the magnetotail. We have always suspected this was what also happens on Saturn. This evidence really strengthens the argument."

The findings reveal a bit more about how auroras form on Saturn. More specifically, they capture the process in action, showing clear evidence of the collapsing magnetotail.

"Our observations show a burst of auroras that are moving very, very quickly across the polar region of the planet," said Nichols in a news release. "We can see that the magnetotail is undergoing huge turmoil and reconfiguration, caused by buffering from solar wind. It's the smoking gun that shows us that the tail is collapsing."

The findings are published in the journal Geophysical Research Letters.