Details of Saturn’s northern lights revealed in new Hubble photos

Saturn’s flickering auroras would challenge even the most vivid northern and southern lights on Earth. 

Newly released photos taken by the Hubble Space Telescope in 2017, during and after Saturn’s summer solstice, show off the ringed planet’s northern lights shining in space. 

The images, taken in ultraviolet light, are “the most comprehensive picture so far of Saturn’s northern aurora,” the European Space Agency (ESA) said in a statement. 

Saturn’s auroras in ultraviolet

On Earth, the lights of the auroras are created when charged particles from the sun crash into our atmosphere, exciting neutral particles and causing a colorful glow. 

While Saturn’s auroras are influenced by the sun, they look very different from Earth’s.

“Because the atmosphere of each of the four outer planets in the Solar System is — unlike the Earth — dominated by hydrogen, Saturn’s auroras can only be seen in ultraviolet wavelengths — a part of the electromagnetic spectrum which can only be studied from space,” the ESA said.

These images of Saturn’s northern lights reveal new details about the planet’s auroras, including that they peak in brightness at dawn, but also pre-midnight.

That later peak in brightness hasn’t been seen before and is thought to be due to the interaction between the sun’s particles and the planet’s magnetosphere at Saturn’s solstice, the ESA said. 

The Hubble observations were taken in coordination with the end of the Cassini mission, which studied Saturn for more than 10 years before its completion in September 2017. 

Details of the new observations are published in a new study in the journal Geophysical Research Letters.