A recent study from the University of California, Berkeley, reveals that hailstorms of “mushballs,” coupled with lightning, are a reality on Jupiter and potentially other gas giant planets. The phenomenon was noted after observations showed nonuniformities in ammonia gas distribution in Jupiter’s atmosphere. This idea was conceptualized back in 2020 by UC Berkeley’s Chris Moeckel and his adviser, Imke de Pater.
Initially skeptical, Moeckel recounted, “Imke and I both were like, ‘There’s no way in the world this is true,’” but persisted, unable to disprove the theory. Their work, featuring the first 3D visualization of Jupiter’s upper atmosphere, suggests most weather on Jupiter is shallow, except for some deeper penetrating storms.
In these storms, ammonia and water combine into mushballs. Moeckel stated, “Every time you look at Jupiter, it’s mostly just surface level. It’s shallow, but a few things — vortices and these big storms — can punch through.” De Pater added, “Juno really shows that ammonia is depleted at all latitudes down to about 150 kilometers, which is really odd.”
Juno’s observations indicate ammonia is dragged lower into the atmosphere through storms, challenging previous assumptions that atmospheres on such planets are well-mixed. “The turbulent cloud tops would lead you to believe that the atmosphere is well mixed,” Moeckel mentioned, analogizing it to a boiling pot with a steady layer beneath.
Juno and Earth-based radio telescope observations support these findings, which add layers to our understanding of gas giants like Jupiter and Saturn. Such data are crucial for interpreting the atmospheres and internal compositions of not only our solar system’s giants but also distant exoplanets.
“The mushball journey essentially starts about 50 to 60 kilometers below the cloud deck as water droplets. The water droplets get rapidly lofted all the way to the top of the cloud deck,” Moeckel explained, highlighting the complex vertical mixing processes.
The study, partly funded by NASA, is a significant contribution towards understanding planetary atmospheres, providing a clearer picture of atmospheric dynamics on Jupiter and, potentially, other gas giants.
