Saturn Experiences Hundred-Year-Long Mega Storms With Impacts That Challenge Our Understanding of the Gas Giant

New research has found that massive, hundred-year-old storms on the exoplanets can reveal clues about the formation of our gas giant neighbors. Astronomers know that the enormous Great Red Spot in Jupiter has existed for hundreds of years. Still, they also discovered that Saturn has mega storms, which have been raging for centuries.

Uncovering the Mega Storms

As early as 1876, astronomical observations revealed the visible storms beneath Saturn's calm outer atmosphere. Some of these storms have been so large that they left visible weather disturbances on their surface when viewed from a telescope. After observing that the fallout from cyclical mega storms can last for centuries, experts reassess the theories regarding the formation of the gas giants.

In the past, some of the evidence of the storms in Saturn could only be detected from radio emissions. This has been the focus of study for an international team of scientists from the University of California and the University of Michigan. In 2015, the National Radio Astronomy Observatory's Very Large Array captured images that depicted radio bands present in the atmosphere of Saturn. This indicates that the gas giant had long-term ammonia gas distribution disruptions, consistent with the effects of storms that lasted for hundreds of years.

Across the northern hemisphere, lighter bands indicative of higher temperatures appeared. These bands were believed to be warmer since the storms in Saturn led to the condensation of ammonia vapor in the atmosphere. The condensed vapor turned into ammonia-rich mushballs and poured into Saturn's depths. The gas giant's deeper layers have cold, nearly inviscid conditions. As a result, pushing the ammonia back into the higher atmosphere by convection currents will take years to happen. This is exactly what the researchers have seen using radio observations with longer wavelengths.

The mega storms on Saturn are composed mainly of hydrogen, helium, methane, water, and ammonia. The cyclones occur once every 20 to 30 years and last longer than previously thought. In terms of make-up and longevity, they differ from the hurricanes on Earth.

A New View at Planetary Formation

The anomalies in the concentration of ammonia gas in Saturn's atmosphere were connected to the past mega storms in the northern hemisphere. According to research lead author Cheng Li, understanding the nature of the largest storms in the Solar System puts the hurricane theories in a wider cosmic context and challenges our recent understanding of the formation of planets.

Astronomers realize that despite being cosmic neighbors, Jupiter and Saturn possess different kinds of storms. The anomalies in the troposphere of Jupiter are related to its colored bands, as confirmed by the revelation from the Juno microwave radiometer. Meanwhile, the anomalies in the brightness temperature in Saturn at radio wavelengths were due to giant storms.

Such differences indicate that the formation of mega storms can differ from planet to planet, an important consideration when studying the nature of exoplanets. Scientists realized that the anomalies detected using radio imaging suggest a shortcoming in the current planet formation theory.

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