Sprites, Elves On Jupiter? NASA's Juno Spots 'Dancing' Lights In Jovian Atmosphere

Are there sprites "dancing" in the atmosphere of Jupiter? Although "sprites" and "elves" are supernatural creatures in English folklore, the magical names are also used for the bright luminous events that surprised scientists scouring Juno data in 2019.

In a new study, a team of researchers describes their discovery of transient luminous events (TLE) in the atmosphere of Jupiter. The phenomenon was spotted thanks to data from NASA's Juno spacecraft, which has been orbiting Jupiter since 2016.

By scouring data from the spacecraft's ultraviolet spectrograph, the researchers observed 11 bright flashes in the region where lightning storms are known to occur. However, the bright flashes that lasted for mere milliseconds were much too high in the atmosphere to just be lightning.

"We suggest that these are observations of TLE in Jupiter's upper atmosphere," the researchers wrote in the study. "In particular, we suggest that these are elves, sprites or sprite halos, three types of TLEs that produce spectacular flashes of light very high in the Earth's atmosphere in response to lightning strikes between clouds or between clouds and the ground."

As the NASA news release on the study explains, sprites look rather like jellyfish, with a "central blob" and tendrils that extend both downward and upward. On the other hand, elves are quite flat but can be larger than sprites.

These events have only been observed on Earth before, the researchers said. Although they have been predicted to be present on other planets as well, it was the first time for the phenomenon to actually be observed on another world.

And on Earth, TLEs tend to flash in red, not the blue ones that the researchers observed in Jupiter's atmosphere. This is because of the difference in what the TLEs are interacting within the atmosphere of the planet

"On Earth, sprites and elves appear reddish in color due to their interaction with nitrogen in the upper atmosphere," study lead and Juno scientist Rohini S. Giles explained in the NASA news release. "But on Jupiter, the upper atmosphere mostly consists of hydrogen, so they would likely appear either blue or pink."

The discovery can help improve the understanding of the phenomenon, the researchers said.

"Now that we know what we are looking for, it will be easier to find them at Jupiter and on other planets," Giles said in the news release. "And comparing sprites and elves from Jupiter with those here on Earth will help us better understand electrical activity in planetary atmospheres."

The study is published in the Journal of Geophysical Research: Planets.