One of the largest storms ever seen on Saturn may have been a victim of its own success, choking when it ate its own tail.
The “Great Springtime Storm” was a colossal maelstrom that raged on Saturn for a record-breaking 267 days during 2010 and 2011. The storm was so vast that it wrapped itself around the planet’s Northern Hemisphere, allowing the storm’s head to encounter its own tail. Even after the storm’s death, the planet continued to feel its effects when it generated the largest and hottest vortex ever seen in the solar system. Scientists had a spectacular front-row seat for the entire storm with NASA’s Cassini spacecraft, which gathered invaluable data about the event.
New research suggests that the storm’s Ouroboros-like consumption of itself may have been its undoing since the maelstrom sputtered out at roughly the same time as the head met the tail, according to a paper in the journal Icarus that appeared on January 10. This is the first time that scientists have ever watched a storm consume itself in this way, but the team is at a loss to explain exactly why the tail-meets-head scenario would have caused the storm’s demise.Storms with this magnitude and behavior can only exist on Saturn. A similar hurricane on Earth would eventually run into features such coastlines or a mountain range and so would have no way to wrap around the planet. The Great Springtime Storm also produced such strong updrafts over such a long time period that they would have sucked out a volume equivalent to Earth’s atmosphere in a mere 150 days.
The Icarus paper provides insight into a lot of the storm’s behavior. Prior to the maelstrom, 17 dark and featureless spots, known as the “String of Pearls” appeared in Saturn’s clouds and stuck around for several years. Researchers speculate that these could have been openings in the cloud layer through which hot pockets of air from deep in Saturn’s interior escaped. Since they occurred in roughly the same place as the storm’s head, scientists think the storm may have erupted from this string of dark spots.
An enormous thunder-and-lightning-filled storm head, stretching 4250 km, nearly two-thirds the radius of Earth, appeared in December 2010. Within months, it had expanded and stretched to 300,000 km, wrapping entirely around Saturn. In mid-June 2011, the head and tail of the storm collided, causing the head to break up into three parts before disappearing. The storm left this region in a highly disturbed state, causing the clouds to darken significantly and altering the wind speeds in its zone.
Above:
Storm Head Meets Storm Tail
A chronology of the storm’s evolution, taken over several months. The topmost image shows the storm’s turbulent beginning while the last one shows it fizzling after the head slammed into the tail. The images have been enhanced to show turbulence in the cloud layers. Click the link below to see the extent of the image.