Thunderstorms on Jupiter are so violent and strong that ammonia-rich hail called “mushballs” could rain down from the sky. Apparently ammonia works similar to anti-freeze when it’s mixed with ice crystals which makes them melt and ultimately creates huge storms.
This new information was collected by NASA’s Juno spacecraft which arrived at Jupiter in July of 2016 and orbits the planet every 53 days. It studies the planet’s atmosphere in order to get a better understanding of Jupiter’s meteorology.
The mission has so far shown rotating white clouds full of ammonia in the upper atmosphere of the planet that measures over 2,000 square miles. These ammonia-rich clouds are located about 10 miles above other clouds and they cause flashes of lighting in addition to casting huge shadows on Jupiter.
Thunderstorms on Jupiter are similar to those that occur here on Earth as they both move around water within the atmosphere. One huge difference, however, is that the thunderstorms on the Gas Giant begin to form approximately 31 miles beneath the storm bands. The temperatures where the storms are formed are around the freezing point which means that if a storm is strong enough, it can move the ice into the upper portion of the atmosphere where it will then melt.
Tristan Guillot, who is a planetary scientist at the Côte d'Azur University in Nice, France, and an author of the papers, explained this further, “On Jupiter as on Earth, a mixture of two thirds water and one third ammonia will remain liquid down to a temperature of -100°C [-148°F],” adding, “The ice crystals which have been lifted high into Jupiter's atmosphere are melted by ammonia — forming a liquid — and become the seeds for exotic hailstones, or "mushballs".”
He went on to say, “The mushballs, being heavier, then fall deeper into the atmosphere until they reach a point where they evaporate. This mechanism drags ammonia and water down to very deep levels in the planet's atmosphere.” “This can potentially explain Juno measurements that Jupiter’s ammonia abundance is variable until at least 100 miles below the visible clouds.”
Guillot went into further details about the storms, “During Jupiter's violent storms, hailstones form from this liquid, similar to the process in terrestrial storms where hail forms in the presence of super-cooled liquid water.” “Growth of the hailstones creates a slush-like substance surrounded by a layer of ice, and these "mushballs" fall, evaporate and continue sinking further in the planet's deep atmosphere.”
According to the data collected by Juno, there is more ammonia found near the equator on Jupiter although the exact amount is currently unclear.
In a second study, a team of international experts created models that indicated that the “mushballs” and storms on Jupiter “dry out” the atmosphere of its ammonia, while a third study detailed the flashes of lightning on the planet. The three papers can be read in full here, here, and here.