Atmospheric phenomena known as "sprites" and "elves" may be spectacularly illuminating the upper cloud layers of Jupiter, according to a newly published study based on data collected by NASA’s Juno spacecraft. These short-lived light displays have been known to manifest on Earth above intense lightening storms, and exist for just a few milliseconds before disappearing.
Jupiter is the largest planet in our solar system, both in terms of volume and mass, and its atmosphere is known to play host to a dizzying array of chaotic vortexes and atmospheric phenomenon.
Astronomers had previously suspected that transient luminous events (TLEs), colloquially referred to on Earth as sprites and elves, could be periodically bursting into life high in the Jovian atmosphere. However, up until now, no direct evidence had been discovered to prove that the rare phenomenon was indeed occurring in Jupiter’s chaotic cloud sea.
Back on Earth sprites are known to be rare, powerful electrical discharges that have been observed to manifest roughly 60 miles (97 km) above towering lightening storms
In terms of structure, sprites appear as a central blob of light some 15 to 30 miles (24 to 48 km) across, with tendrils of lightening extending above and below, giving the phenomena the appearance of an otherworldly jellyfish. Elves, meanwhile, look like flat disks of light that can span an incredible 200 miles (320 km) across.
A new study that used data collected by NASA’s Juno spacecraft has presented the evidence to suggest that elves or sprites are indeed present high in Jupiter’s atmosphere.
The researchers made the discovery while reviewing data harvested by Juno’s ultraviolet spectrograph instrument (UVS), which was designed to characterize the gas giant’s powerful aurora. Spectrometers essentially split light into its constituent wavelengths, and display the information as a colorful spectra. Scientists can analyze this information to understand what processes are occurring around distant heavenly bodies.
Upon examining the UVS data, the team noticed 11 extremely brief but intense bursts of ultraviolet light above a region where thunderstorms are known to exist. The locations of the flashes, some 186 miles (300 km) above the lighting-saturated water-cloud region, ruled out the possibility that the emissions were the result of super-powerful lightening bolts.
This led the team to conclude that the UV signatures were the result of sprites or possibly elves in the Jovian atmosphere.
"On Earth, sprites and elves appear reddish in color due to their interaction with nitrogen in the upper atmosphere," said Rohini Giles, a scientist working on the Juno mission and lead author of the new paper. "But on Jupiter, the upper atmosphere mostly consists of hydrogen, so they would likely appear either blue or pink."
The study represents the first observation of sprites or elves occurring on another planet. It also stands to reason that the same phenomena could be occurring in the atmospheres of other enormous gas giants spread throughout the universe.
The paper has been published in the Journal of Geophysical Research: Planets.
Source: NASA