Saturn's storms experience long-lasting impactafter it was first spotted by Gian Domenico Cassini in 1665. It has remained visible, barring a span from 1713 to 1830. Although Cassini's storm might differ from today's, the existing red spot has endured for almost 200 years. While storms on other gas planets arise and fade, Jupiter's storm stands out for its longevity.
Distinguished by its deep red hue against Jupiter's pale surface, the origin of the red spot's color remains uncertain. Nonetheless, the storm draws up molecules from Jupiter's depths. Interaction with ultraviolet light might produce reddish-brown tholins, similar to those in Titan's atmosphere. The spot's high-contrast appearance aided its discovery, which might have occurred later without modern technology.
Saturn, too, experiences significant storms periodically. The Cassini-Huygens mission revealed the latest instance, where a trail of white pierced Saturn's atmosphere, earning the name "Great White Spot." A similar phenomenon was noted by the Hubble Space Telescope in 1994.
Records of white storms on Saturn date as far back as 1876, initially believed to be distinct due to their occurrence at various latitudes. These storms have a recurrence rate of every 20-30 years, lasting just a few years each time. However, a recent study published in Science Advances unveils that these storms endure much longer than previously thought.
Periodically, Saturn also experiences notable storms. The Cassini–Huygens mission highlighted the most recent occurrence when a streak of white pierced Saturn's atmosphere, earning the moniker "Great White Spot." A similar phenomenon caught the attention of the Hubble Space Telescope in 1994.
Notably, records of white storms on Saturn trace back to 1876. Originally believed to be separate due to varying latitudes of observation, these storms manifest every 20-30 years and typically persist for a few years. However, a recent study published in Science Advances has revealed that these storms endure for significantly longer durations.
Rather than using visible light, the research team focused on radio observations gathered by the Very Large Array to study Saturn. The upper atmosphere of Saturn is mostly transparent to radio light, allowing astronomers to delve deeper into its atmospheric layers.
Through this approach, the team detected disruptions in Saturn's deeper atmospheric levels, particularly in the abundance of ammonia, a crucial component of the Great White Spots. These disruptions were evident at latitudes corresponding to historical storm occurrences.
This suggests that Saturn's periodic major storms agitate the planet's atmosphere over decades. Interestingly, the team identified a disruption band that doesn't align with known observations, potentially stemming from a storm predating the one in 1876. This indicates that remnants of Saturn's storms could endure for centuries.
Continued observations are poised to unveil insights into the genesis of these storms on Saturn. Anticipating the potential appearance of the next great storm in a few years, radio astronomy holds promise for uncovering how Saturn's deep atmospheric layers contribute to the emergence of storms on the planet's surface.