Is Jupiter's Great Red Spot an impostor? Giant storm may not be the original one discovered 350 years ago

Jupiter's Great Red Spot, a massive storm on the planet's surface, has long been associated with the "Permanent Spot" observed by astronomer Giovanni Cassini in 1665. However, new research indicates that these two vortexes may not be the same. In fact, the current Great Red Spot is likely a newer and younger storm, according to a recent study.

Although the "Permanent Spot" had been observed in the 17th century, it mysteriously disappeared from astronomers' radar, with the last recorded sighting in 1713. It wasn't until 1831 that a new spot was discovered, situated on the same latitude as the original. This newly identified spot is the Great Red Spot we are familiar with today.

By examining measurements of sizes and movements, researchers concluded that it is highly unlikely that the current Great Red Spot is the same vortex observed by Cassini. Instead, they suggest that the "Permanent Spot" likely vanished sometime between the 18th and 19th centuries. Therefore, the Red Spot's longevity now exceeds 190 years.

To understand the formation of the Great Red Spot, scientists conducted computer simulations using data on its changes over time. These simulations point to wind instability as the leading theory behind the development of the observed elongated atmospheric cell.

One noteworthy observation is that the Great Red Spot is shrinking. Its size, once measured at 24,200 miles (39,000 kilometers) along its longest axis in 1879, has currently reduced to 8,700 miles (4,000 kilometers) on the same axis. Further simulations will be conducted to predict if the Great Red Spot will eventually disappear, akin to Cassini's Permanent Spot, only to potentially reappear centuries later as a new vortex.

This ongoing research provides valuable insights into the fascinating phenomenon observed on Jupiter and highlights the ever-evolving nature of the Great Red Spot, which has enthralled astronomers for centuries.