Aurora borealis, and its southern counterpart, aurora australis, account for some of the most stunning natural events on Earth—but the phenomenon isn't limited to our planet. The European Space Agency and NASA recently released images captured by the Hubble Space Telescope of electric-blue rings lighting up Saturn's northern pole.
On Earth, auroras occur when electrons from the Sun collide with oxygen and nitrogen in the atmosphere, thus transferring some energy to the gas molecules. The gases eventually release the energy as photons, or light particles, which can take the form of colorful waves of light in the sky. This effect is amplified by the Earth's magnetic field, which is why auroras appear visible at the north and south poles where the magnetic field is strongest.
This same process plays out 746 million miles away on the ringed planet. One major difference is that Saturn's atmosphere is largely composed of hydrogen, which means its auroras are most visible in ultraviolet light. These images of Saturn's lights were taken with UV light over a seven-month period in 2017. Other gas giants in our solar system—Jupiter, Uranus, and Neptune—host their own polar light shows as well.
Astronomers observed that Saturn's northern lights peak twice during its short 11-hour day: once at dawn and once before midnight. You can view a time-lapse of the images below.