'Disappeared for 118 years': The Great Red Spot on Jupiter probably formed in the early 1800s
Produced by: Tarun Mishra Designed by: Manoj Kumar
Defining Feature of the Solar System
Jupiter's Great Red Spot (GRS) is a massive storm observed since the 1600s, known for its counter-clockwise rotation and wind speeds exceeding 400 km/h.
Credit : NASA
Historical Observations
Early observations of the GRS date back to 1632 when a German Abbott noted a storm on Jupiter. Giovanni Cassini observed a similar spot in 1665, which was continuously monitored until 1713 and named the Permanent Spot (PS).
Lost and Found
After disappearing for 118 years, the GRS was observed again by S. Schwabe in 1831. This observation is considered the first of the current GRS, suggesting it may have reformed at the same latitude.
Debate on Longevity
Recent research indicates that it is unlikely the current GRS is the same as the PS observed by Cassini. The PS likely disappeared between the mid-18th and 19th centuries, with the current GRS being at least 190 years old.
Shrinking Storm
The GRS was 39,000 km long in 1879 but has since shrunk to 14,000 km and become more rounded. This transformation has been documented through various observations and imaging technologies.
Credit : NASA
Advanced Studies
Space telescopes and spacecraft, including NASA's Voyager 1, Galileo, and Juno missions, have provided detailed images and data on the GRS. Juno's measurements revealed the GRS is about 500 km deep.
Formation Theories
Researchers used historical records and computer simulations to study the GRS. They tested hypotheses involving superstorms and smaller vortices but found these mechanisms unlikely to have formed the current GRS.
Instabilities and Formation
Simulations of Jupiter’s South Tropical Disturbance (STrD) created a storm resembling the GRS. The STrD likely trapped winds, forming an elongated cell that shrank and became the GRS observed today.
Conclusion
The study concludes that the GRS likely formed in the mid-1800s and has since evolved into its current state. This finding helps explain the storm's longevity and changing characteristics over time.