Possible Transient Luminous Events observed in Jupiter's upper atmosphere

TL;DR

This paper reports the detection of transient luminous events in Jupiter's upper atmosphere, similar to Earth's elves and sprites, observed via UV emissions with implications for planetary atmospheric phenomena.

Contribution

First observational evidence of Jupiter's upper atmospheric transient luminous events, expanding understanding of planetary lightning phenomena beyond Earth.

Findings

Detected 11 transient bright flashes in Jupiter's atmosphere.

Flashes last approximately 1.4 milliseconds with exponential brightness decay.

Spectral analysis suggests source altitude of about 260 km above the 1-bar level.

Abstract

11 transient bright flashes were detected in Jupiter's atmosphere using the UVS instrument on the Juno spacecraft. These bright flashes are only observed in a single spin of the spacecraft and their brightness decays exponentially with time, with a duration of ~1.4 ms. The spectra are dominated by H2 Lyman band emission and based on the level of atmospheric absorption, we estimate a source altitude of 260 km above the 1-bar level. Based on these characteristics, we suggest that these are observations of Transient Luminous Events (TLEs) in Jupiter's upper atmosphere. In particular, we suggest that these are elves, sprites or sprite halos, three types of TLEs that occur in the Earth's upper atmosphere in response to tropospheric lightning strikes. This is supported by visible light imaging, which shows cloud features typical of lightning source regions at the locations of several of the bright flashes. TLEs have previously only been observed on Earth, although theoretical and experimental work has predicted that they should also be present on Jupiter.