Nuages en rotation sur Jupiter
			
		
		
		
			Where is Jupiter's ammonia?
Gaseous ammonia was expected to be seen in 
Jupiter's 
upper atmosphere by the orbiting 
Juno spacecraft -- but in many clouds is almost absent.
Recent Juno data, however, gives some clues: some high-level clouds 
appear to be home to an unexpected type of electrical discharge dubbed 
shallow lightning.
Great charge separations are needed for 
lightning, 
which might be created by colliding mushballs lifted by rising updrafts of gas. 
Ammonia and water stick to these 
mushballs 
which rise until they get too heavy -- after which they 
fall deep into 
Jupiter's atmosphere 
and melt. 
By this process, ammonia found missing from 
Jupiter's upper atmosphere reappears below. 
Pictured by Juno, churning clouds on Jupiter show not only mesmerizing complexity but some high-level, light-colored pop-up clouds.
Understanding atmospheric dynamics on Jupiter 
gives valuable perspective to similar atmospheric and 
lightning phenomena that occur on our home Earth.