NASA’s Juno spacecraft recently caught this ghostly green flash in a massive storm swirling near Jupiter’s north pole.
The huge flash of lightning shines brightly against the dark gray swirl of the storm, even from Juno’s vantage point 19,900 miles above Jupiter’s cloud tops. Lightning often flashes between the clouds at the higher latitudes of a stormy Jupiter, especially in the north. NASA’s Juno spacecraft is helping to shed light on the gas giant’s wild extraterrestrial past.
Citizen scientist Kevin M. Gill processed the image from Juno’s raw data.
Giant alien lightning bolts
The clouds that form this raging storm are a mixture of water and ammonia.
NASA
A recent study says that lightning works the same way on Jupiter as it does here on Earth – only with about 10,000 times more energy. Storm clouds are turbulent, chaotic places, with updrafts that push water droplets aloft and downdrafts that simultaneously throw down hail and small ice particles. As these storm-tossed pieces of water and ice collide with each other, the collisions strip electrons from the water droplets. This turns the storm cloud into a giant battery with a positive charge at the top and a negative charge at the bottom.
“When the strength of the charge overcomes the insulating properties of the atmosphere, ZZZ-ZAP!” as the National Oceanic and Atmospheric Administration (NOAA) puts it.
Lightning is jagged and bifurcated because the energy travels in a series of short spikes that often follow a zigzag path instead of a long, smooth jump from cloud to cloud. This is because the energy that is released in lightning tends to follow the easiest path from a negatively charged region to a positively charged one. Scientists have known for years that lightning behaves this way here on Earth, and data from the Juno’s Waves instrument recently showed that it does the same in Jupiter’s clouds, which are made of a mixture of water and ammonia (rather than mostly water like clouds on the ground).
But there are some big differences. Here on Earth, most lightning occurs near the equator, but on Jupiter, lightning mostly occurs in storms at higher latitudes. The gas giant’s largest and best-known storm, the 10,000-mile-wide Great Red Spot, appears to be just wind and no lightning. Scientists who study alien weather aren’t yet sure exactly why this is, but it’s one of the mysteries Juno may eventually help solve.
Our stormy solar system
Jupiter was the first planet besides Earth to be found to have lightning. NASA’s Voyager 1 spacecraft detected the telltale radio signals of lightning in Jupiter’s vast storms during its flyby of the gas giant in 1979, and since then a series of spacecraft have studied Jupiter’s lightning in more detail.
The gas giant isn’t the only other world with lightning bolts. Saturn and Uranus definitely have lightning to add an ominous atmosphere to their storms. Mars probably doesn’t, as its atmosphere is too thin, but the jury’s still out; the Mars Global Surveyor satellite has spotted some bright flashes in Martian dust storms that could be lightning or something. Saturn’s moon Titan also likely lacks lightning because the chemicals that make up its atmosphere may not lose electrons in the same way that water molecules do. However, the planners of the upcoming Dragonfly mission are taking precautions just in case. Venus and Neptune are also still completely open questions.