True age of Jupiter’s Great Red Spot REVEALED

Scientists have determined the true age of Jupiter’s Great Red Spot, revealing the storm system is younger than the US.

The massive swirling storm system was originally thought to have been discovered by astronomer Giovanni Domenico Cassini in 1665, but a new study found it was not the most recent spot.

That means the Great Red Spot is roughly 190 years old since it was last documented in 1831.

Researchers from Spain also discovered that the storm system is shrinking each year, dropping from 24,200 miles wide when it was observed in 1879 to just 8,700 miles wide today – suggesting it could also disappear one day. 

Researchers looked at early observations dating back to Cassini’s discovery, including his drawing of the celestial event, and used computer modeling to reveal the spot’s age and how it materialized.

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Cassini first observed the Great Red Spot in the 17th Century, dubbing it the ‘permanent spot,’ which persisted until 1713 when astronomers could no longer find it.

More than 100 years later, astronomers observed a similar storm in the same region, leading them to question if it was the ‘permanent spot’ or a different one that happened to form in the same location.

‘From the measurements of sizes and movements, we deduced that it is highly unlikely that the current Great Red Spot was the ‘Permanent Spot’ observed by Cassini,’ said Agustín Sánchez-Lavega, the study’s lead author and planetary scientist at the University of the Basque Country in Bilbao, Spain.

‘The ‘Permanent Spot’ probably disappeared sometime between the mid-18th and 19th centuries, in which case we can now say that the longevity of the Red Spot exceeds 190 years,’ he added.

NASA’s Juno spacecraft has orbited Jupiter since 2016, taking images of the spot that revealed it was shallow and thin.

The data had suggested that it formed from a giant superstorm, like the ones on Saturn.

Trapped between two jet streams, the Great Red Spot is an anticyclone swirling around a center of high atmospheric pressure caused by a superstorm that forces it to rotate in the opposite direction of hurricanes on Earth, creating an anticyclone.

The strong winds in the spot stir up chemicals like ammonia ice particles in the upper layer that, when exposed to the sun’s rays, give it a red hue.

More research needs to be conducted to understand why the Great Red Spot is shrinking over time and to further understand how it has stayed in the same location for nearly two centuries.

Scientists hope to eventually understand whether the spot will disintegrate and disappear once it shrinks to a certain size, or if it will reach a point where it is stable, allowing it to endure for decades to come.

‘It has been very motivating and inspiring to turn to the notes and drawings of Jupiter and its Permanent Spot made by the great astronomer Giovanni Domenico Cassini, and to his articles of the second half of the 17th century describing the phenomenon,’ Sánchez-Lavega said.

‘Others before us had explored these observations, and now we have quantified the results.’