New study finds similarities in lightning on Earth and Jupiter

Lightning similarities 

The authors demonstrate that, despite the vast differences in size and structure between our solar system's two worlds, some lightning phenomena may be comparable. 

The initiation of lightning on Jupiter may be comparable to "return strokes" inside lightning clouds in Earth's atmosphere. Lightning strikes are generally made up of multiple individual strikes. Each return strike of lightning is marked in rapid succession, separated by a few milliseconds (typically 40 to 50 milliseconds).

They highlight the “lightning initiation processes on Jupiter are found to pulsate with a similar rhythm to lightning that occurs inside clouds on Earth.”

The team examined five years of high-resolution data collected by the Juno spacecraft's radio receiver instrument for this study. The spacecraft is currently in a polar orbit around Jupiter. 

After the examination of the pulsating data from the lightning discharges, the team noted the occurrence of radio pulses on Jupiter with time separations of about one millisecond.

This observation, according to the official release, suggests "step-like features of lightning initiation similar to observations from thunderstorms on Earth."

Lightning on Earth

On Earth, cloud-to-ground lightning occurs when the negative charges in a thundercloud collide with the positive charges on the ground, similar to how opposite charges attract in a battery. And it is during this phenomenon that a powerful electric discharge occurs, resulting in the formation of a lightning flash.

On Earth, the majority of lightning strikes occur near the equator, but evidence suggests that on Jupiter, it occurs mostly near the hemispheres, particularly the northern one. 

With the information we have, this new study opens up a lot of new areas to be explored in relation to Jupiter's lightning flashes, including why they don't occur near the planet's equator, which is still largely unknown. On the other hand, recent discoveries indicate that different types of lightning may be occurring on the planet, like shallow lightning. As per NASA, this type of lightning is triggered by the formation of clouds containing an ammonia-water solution, whereas lightning on Earth is caused by water clouds.

The study is led by the Institute of Atmospheric Physics of the Czech Academy of Sciences in Prague. And the findings have been published in the journal Nature Communications.

Study abstract:

Our knowledge about the fine structure of lightning processes at Jupiter was substantially limited by the time resolution of previous measurements. Recent observations of the Juno mission revealed electromagnetic signals of Jovian rapid whistlers at a cadence of a few lightning discharges per second, com- parable to observations of return strokes at Earth. The duration of these dis- charges was below a few milliseconds and below one millisecond in the case of Jovian dispersed pulses, which were also discovered by Juno. However, it was still uncertain if Jovian lightning processes have the fine structure of steps corresponding to phenomena known from thunderstorms at Earth. Here we show results collected by the Juno Waves instrument during 5 years of mea- surements at 125-microsecond resolution. We identify radio pulses with typical time separations of one millisecond, which suggest step-like extensions of lightning channels and indicate that Jovian lightning initiation processes are similar to the initiation of intracloud lightning at Earth.