Lighting is an atmospheric phenomena that we are very familiar with. In fact, approximately 100 lightning strikes occur every second on Earth. This is visually evident when one looks at footage recorded from the International Space Station (ISS) during orbits over the night side of the Earth.
Lighting is an electrical discharge between a positively charged and negatively charged source. These charges most likely form due to static charges building up between particulates of ice and dust that are raised high up into the atmosphere. There is still much to learn regarding the formation of lightning discharges within the clouds. For example, the processes that result in the positive charges moving up and the negative charges moving down is still unknown. Once this is achieved, an electrostatic potential is built up between the two charges, which results in an electrical discharge (or lightning).
Lightning can occur within a cloud, between clouds, or from cloud to ground. The electrical discharges on Jupiter are more powerful than those on Earth, although the total light output is roughly equal to Earth’s due to the relative scarcity of the bolts. In this photo, you can see the many bright flashes on Jupiter’s night side. These flashes form in the low cloud layers were water clouds rise from the interior troposphere and circulate in convection currents within the thin atmospheric layer. The same static charges build up within these clouds as they do Earth.
It is remarkable to think that these atmospheric phenomena, which were once thought to be purely terrestrial, can exist in the farthest and coldest regions of the Solar System. It is only a matter of time until we discover these bright flashes in the clouds of exoplanets!
