In 1665, astronomer Giovanni Domenico Cassini observed a massive storm raging on Jupiter that became known as the Great Red Spot, a swirling, oval-shaped cloud nearly twice the width of Earth. But new research suggests that the reddish feature Cassini spotted was different to storms seen today.
Using historical observations of Jupiter from the 17th century, a team of scientists Great Red Spot This event likely lasted only 190 years, in contrast to the 300-year swirling winds. paper Published in Geophysical Research LettersThe researchers claim that the swirling storm Cassini observed dissipated, only for a new one to form in its place a few years later.
After discovering a dark, reddish oval object on Jupiter, Cassini and other astronomers continued to observe the storm until 1713. No more storms were observed for over a century after that. It wasn’t until 1831 that astronomers observed a similar oval shape at the same latitude. Since then, scientists have debated whether it was the same storm or a different one.
The authors of the new paper say that the incorrectly named “Eternal Spot” likely disappeared sometime between the mid-18th and 19th centuries, while Jupiter’s Great Red Spot may date back at least 190 years.
The Great Red Spot is also much larger than its predecessor, stretching over 200 miles (350 km). When first observed, the Great Red Spot stretched over 24,200 miles (39,000 km), but has since shrunk. Today, the storm stretches to 8,700 miles (14,000 km) and has a more rounded shape. Research suggests that previous observations of the spot suggest that a storm would have needed to be three times larger to rival the Great Red Spot.
The Great Red Spot is the largest known storm in the solar system, covering 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 was able to rage for so many years may have to do with Jupiter’s gaseous nature. While storms on Earth tend to die down once they reach land, Jupiter is made up of a liquid layer rather than a solid surface.
Understanding the giant storms is not easy, as Jupiter’s clouds prevent a clear view of the Great Red Spot in the lower atmosphere. A new study suggests that the Great Red Spot may have formed from a giant superstorm that merged with several smaller vortices. Although much remains to be learned about Jupiter’s violent storms, scientists can rely on historical observations to glean clues about the mysteries of the Jovian system.
“It was incredibly inspiring and thought-provoking to read the notes and drawings that the great astronomer Jean-Dominique Cassini made about Jupiter and its sunspots, as well as his late 17th-century papers describing this phenomenon,” Agustín Sánchez Lavega, a planetary scientist at the University of the Basque Country in Bilbao, Spain, and lead author of the paper, said in a statement. “Others have investigated these observations before us, and now we have quantified the results.”
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