But is the storm we see today the same one that was recorded by the great Italian astronomer centuries ago?<\/p>
A new set of simulations may have settled the debate once and for all, suggesting our spot and Cassini\u2019s are two separate things.<\/p> After Cassini first noticed what he referred to as the Permanent Spot, he and others observed the feature continuously until 1713, when it vanished from the record for 118 years.<\/p> Then in 1831, astronomers again started to see a clear, oval structure on the planet, at the same latitude as the Permanent Spot.<\/p> This Great Red Spot has been continuously monitored for over 190 years and is now known to be a huge vortex in Jupiter\u2019s upper atmosphere.<\/p> However, it remained unclear whether the feature is the same as Cassini\u2019s Permanent Spot or a completely new weather system.<\/p> To find the answer, a team used observations of the planet from the last few decades \u2013 including those taken by the Juno probe currently in orbit<\/a> \u2013 to create simulations of how the Great Red Spot formed.<\/p> These investigated three different potential formation methods.<\/p> Two of these methods \u2013 one where the Great Red Spot is the product of a giant superstorm; another where it is several smaller vortices combined \u2013 didn\u2019t produce the kind of storm we see today.<\/p> The third method, however, took a look at instabilities caused by the fast-flowing jet streams that flow parallel to the band where the Great Red Spot resides, but in the opposite direction.<\/p> In this case, the simulations did result in a system similar to the Great Red Spot.<\/p> The study then compared this simulation to historical records, tracking how the Great Red Spot has changed over time.<\/p> In 1879, the Great Red Spot was around 39,000km (24,200 miles) at its widest, but now measures just 14,000km (8,700 miles) across.<\/p> Comparing these changes with the simulations suggests the Great Red Spot first formed in the 19th century, long after the Permanent Spot seen by Cassini disappeared.<\/p> “From the measurements of sizes and movements, we deduced that it is highly unlikely that the current Great Red Spot was the \u2018Permanent Spot\u2019 observed by Cassini,” says Agust\u00edn S\u00e1nchez-Lavega from the University of the Basque Country in Bilbao, Spain, who led the study.<\/p> Words: Chris Lintott<\/em><\/p> The Great Red Spot is the second most recognisable planetary feature behind Saturn\u2019s rings<\/a>.<\/p> I remember being gobsmacked when viewing the planet through Patrick Moore\u2019s 12.5-inch reflector, where the Great Red Spot seemed to have faded very nearly completely.<\/p> More recently, the spot seemed to develop red \u2018flakes\u2019, which turned out to be gas being pulled into the eye of the living, breathing storm.<\/p> When it does fade away completely \u2013 which might happen in the next decade or so \u2013 it\u2019ll be a sad day for back garden observers everywhere.<\/p> But this new research has a silver lining, suggesting a new spot will be along soon, just as our spot replaced Cassini\u2019s.<\/p>![\"The](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2024\/08\/cassini-sketch-jupiter-1024x574.jpg?fit=800%2C448\")
History of observing the Great Red Spot<\/strong><\/h2>
![\"An](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2020\/08\/Voyager-Jupiter-d79ec02-1.png\")
The same storm?<\/strong><\/h2>
![\"An](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2019\/08\/Jupiter-Juno-aa01b7c-e1660812643275.jpg\")
![\"Jupiter](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2019\/12\/12-Rouzbeh-Bidshahri-Jupiter-027424d-e1624365704819.jpg\")
Observing the Great Red Spot<\/strong><\/h2>