While NASA's Hubble Space Telescope, orbiting around Earth, was able to observe the northern auroras in ultraviolet wavelengths, the agency's Cassini spacecraft, orbiting around Saturn, got complementary close-up views in infrared, visible-light and ultraviolet wavelengths, NASA said of the images released Tuesday.
Cassini could also see northern and southern parts of Saturn that don't face Earth, it said.
"Saturn's auroras can be fickle -- you may see fireworks, you may see nothing," said Jonathan Nichols of the University of Leicester in England, who led the work on the Hubble images. "In 2013, we were treated to a veritable smorgasbord of dancing auroras, from steadily shining rings to super-fast bursts of light shooting across the pole."
The new data yield clues to a longstanding mystery about the atmospheres of giant outer planets, NASA scientists said.
"Scientists have wondered why the high atmospheres of Saturn and other gas giants are heated far beyond what might normally be expected by their distance from the sun," said Sarah Badman, a Cassini visual and infrared mapping spectrometer team associate at Lancaster University in England. "By looking at these long sequences of images taken by different instruments, we can discover where the aurora heats the atmosphere as the particles dive into it and how long the cooking occurs."
Astronomers said they hope additional Cassini work will illuminate how clouds of charged particles move around the planet as it spins and receives blasts of solar material from the sun.
"The auroras at Saturn are some of the planet's most glamorous features -- and there was no escaping NASA's paparazzi-like attention," said Marcia Burton, a Cassini scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.