Jupiter’s red spot may have evolved more than once

Researchers may have solved the mystery of the Great Red Spot, a massive storm swirling above Jupiter’s surface.

Astronomer Giovanni Domenico Cassini first observed a vortex over the same area of ​​Jupiter in 1665 and named it the “Permanent Spot” – but scientists weren’t sure if it was the same storm we see today. In a new study published this month in Geophysical Research Lettersresearchers analyzed historical observations of the site and determined that the two storms were likely different.

“From measurements of sizes and motions, we conclude that it is highly unlikely that the current Great Red Spot is the ‘Permanent Spot’ observed by Cassini,” Agustín Sánchez-Lavega, a planetary scientist at the University of the Basque Country in Spain. who led the research, says in a statement. “The ‘permanent spot’ probably disappeared sometime between the middle of the 18th and 19th centuries, in which case we can now say that the lifetime of the Red Spot exceeds 190 years.”

Scott Bolton, a physicist at the Southwest Research Institute who was not involved in the study, says The new scientist‘s Leah Crane that it is difficult to draw conclusions from the hand-drawn images that researchers relied on in part to get the first data on the site.

“I think what we can see is not so much that a storm went away and then a new one came in almost exactly the same place – it would be a very big coincidence if it happened at the same exact latitude or even a similar latitude,” says Bolton The new scientist. “It could be that what we’re really watching is the evolution of the storm.”

After Cassini first spotted Jupiter’s spot, astronomers continued to observe it until 1713. After that, the so-called Permanent Spot seemingly disappeared. “No astronomer of the time reported any site at this latitude for 118 years,” says Sánchez-Lavega. Mashableis Mark Kaufman. Another site was not reported until 1831, but scientists have been watching them ever since.

The current spot has shrunk from 24,200 miles in 1879 to about 8,700 miles today. But that’s still longer than Earth’s diameter (just over 7,900 miles). The storm’s winds can reach speeds of up to 400 miles per hour, and according to NASA, scientists still aren’t sure how chemicals in the atmosphere can give it its red hue.

For the new study, the researchers turned to drawings of the original stain, as well as drawings of the new stain from 1831 to 1879, photographs from 1879 to 1980, and digital images from 1980 to 2023.

“I love articles like this that delve into pre-photo observations,” CNN’s Ashley Strickland told Michael Wong, a research scientist at the University of California, Berkeley, who was not involved in the findings.

Centuries of data have allowed scientists to analyze how the size and movement of storms have changed over time. Early drawings suggested that the Persistent Spot was much smaller than the current spot—meaning it would have had to grow at rates atypical of a Jovian storm to reach the size of the Great Red Spot in the 19th century. The new scientist writes. Moreover, the storm now appears to be diminishing.

The researchers also explored possible explanations for how the Great Red Spot formed by running simulations of the behavior of a storm in Jupiter’s atmosphere. The most likely scenario was that instability in the planet’s intense atmospheric winds caused the storm, according to the statement.

Future research will examine how the spot has remained relatively stable over long periods of time and how it might continue to evolve.

“We don’t know what the future will be like [Great Red Spot] it is,” says Sánchez-Lavega Mashable. It could disintegrate if it continued to shrink, or “it could reach a stable size and persist for a long time.”