Classical astronomers have observed a different large red spot on Jupiter

In 1665, astronomer Giovanni Domenico Cassini observed a huge storm blowing over Jupiter. They became known as the Great Red Spot, and are swirling, oval-shaped clouds roughly twice the width of Earth. However, new research suggests that the red-coloured feature observed by Cassini is not the same storm we see today.

Using historical observations of Jupiter from the 17th century, a team of scientists found that Jupiter Big red spot It would likely only last 190 years versus the 300 years of swirling winds. in paper Published in Geophysical Research LettersResearchers believe that the swirling storm observed by Cassini has now disappeared, but a new storm appeared in its place years later.

After discovering Jupiter’s dark, reddish oval, Cassini and other astronomers continued to monitor the storm until 1713. The storm was not seen for more than a century after that. It was not until 1831 that astronomers observed a similar ellipse at the same latitude. Since then, scientists have debated whether it was the same storm or a different storm.

The spot, dubbed the “permanent spot,” likely disappeared sometime between the mid-18th and 19th centuries, according to the researchers behind the new research. On the other hand, Jupiter’s Great Red Spot may date back at least 190 years.

The Great Red Spot is also much larger than its older counterpart, extending more than 200 miles (350 kilometers). When it was first observed, the Great Red Spot extended more than 24,200 miles (39,000 km) but has since begun to shrink. Today, the storm extends 8,700 miles (14,000 kilometers) and is more rounded in shape. Previous observations of the Permanent Spot indicate that the size of the storm would have tripled compared to the Great Red Spot, according to the study.

The Red Spot is the largest known storm in the solar system, about one-sixth the diameter of Jupiter itself. Unlike hurricanes on Earth, the Great Red Spot rotates counterclockwise, indicating that it is a high pressure system. The reason the storm has persisted for all these years may have to do with Jupiter’s gaseous nature. Storms on Earth tend to dissipate once they reach Earth, but Jupiter is made up of liquid layers rather than a solid surface.

Understanding the giant storm is not easy, as Jupiter’s clouds obstruct a clear view of the Great Red Spot in its lower atmosphere. The new study suggests that the red spot may have formed from a giant storm, with several smaller eddies merging together. There’s still a lot to learn about Jupiter’s raging storms, but scientists can turn to historical observations to gather clues about the secrets of the Jovian system.

“It was very stimulating and inspiring to return to the observations and drawings of Jupiter and its permanent spot by the great astronomer Jean-Dominique Cassini, and to his articles in the second half of the 17th century describing this phenomenon,” said Agustín Sánchez-La Vega, a planetary scientist at the University of Canton. Basque in Bilbao, Spain, and lead author of the new paper, said in a statement. “Others before us have explored these observations, and now we have measured the results.”

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