Jupiter’s iconic red spot may be an imposter

Jupiter is known as the biggest planet in our solar system, but another recognisable characteristic is the iconic Great Red Spot visible on its surface.

However, the red spot we see today may not actually be the same red spot that was first discovered 350 years ago.

In 1665, Italian astronomer Giovanni Cassini spotted the "Permanent Spot" on Jupiter but then for centuries astronomers seemingly lost track of it.

But new research published in the journal Geophysical Research Letters on June 16, suggests our assumption that the "Permanent Spot" is the Great Red Spot is incorrect - and instead it is a newer storm that has caused the present vortex.

From 1713, we lost sight of the "Permanent Spot," and then over a century later in 1831 astronomers noticed a new spot which coincidentally was on on the same latitude as the previous one - which we recognise as Great Red Spot.

To understand the changes of the Great Red Spot over time, Agustín Sánchez-Lavega, a planetary scientist at the University of the Basque Country in Bilbao, Spain, and his colleagues used data to run computer simulations in order to see how vortex appeared.

It is thought that the Great Red Spot - otherwise known as an "elongated atmospheric cell" - was produced due to wind instability on the planet.

"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," Sánchez-Lavega explained in a statement.

"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."

Meanwhile, observations over time also note how the Great Red Spot is shrinking. Back in 1879, the spot size was 24,200 miles (39,000 kilometers) along its longest axis, compared to being just 8,700 miles (4,000 kilometers) today.

Researchers will analyse whether the Great Red Spot will eventually disappear like Permanent Spot did, or if a new vortex will appear again in the future, through carrying out more simulations.

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