Jupiter’s weather just got even stranger. A new study published in the Journal Science Advances revealed that the gas giant’s turbulent thunderstorms create massive, softball-sized hailstones called «mushballs,» made of ammonia and water ice. These violent storms churn Jupiter’s atmosphere so deeply that they may explain a long-standing mystery among the scientists: the missing ammonia in the planet’s upper layers. For years, scientists were puzzled over why deep pockets of ammonia seemed absent across Jupiter’s atmosphere.
Mushballs Shake Up Old Assumptions
As per a report by LiveScience, Scientists believed Jupiter’s atmosphere was well mixed, much like a pot of boiling water. However, after analysing a massive 2017 storm captured by Juno, researchers found that even local storms can punch ammonia deep into the planet, shattering the old assumption. “The top of the atmosphere is actually a pretty poor representation of what the whole planet looks like,” explained study lead author Chris Moeckel from the University of California, Berkeley, told the publication. On April 15, 2025, as per EarthSky, his team’s findings suggest that the atmosphere becomes well-mixed only much deeper down than previously thought.
Ammonia as a Tracer Beneath the Clouds
Jupiter’s thick cloud cover blocks direct observation, and ammonia acts as a critical tracer to understand the hidden activity beneath the clouds. Scientists theorised in 2020 that Jupiter’s powerful storms lift ammonia-rich ice particles to high altitudes, where they combine with water ice to create a mushy, slushy hailstone. These mushballs then grow larger and heavier, cycling up and down in the atmosphere before plunging deep, carrying ammonia and water with them. This process leaves the upper atmosphere depleted, matching observations from Juno.
Confirmation came during Juno’s February 2017 flyby. While passing over a storm zone, the spacecraft detected an unexpected deep signal rich in ammonia and water beneath the storm clouds. Moeckel recalled spotting the discovery while casually running data on his laptop at a dentist’s office, describing the moment he realised the mushball theory must be true.
A Universal Phenomenon Beyond Jupiter
Researchers now believe that Jupiter might not be unique. Gas giants across the universe and even newly forming planets could experience similar mushball processes. “I won’t be surprised if this is happening throughout the universe,” Moeckel told to LiveScience, suggesting that Jupiter’s stormy secrets may echo far beyond our solar system.
