Jupiter’s Great Red Spot Enigma: Unexplained Oscillations Baffle Astronomers
![Jupiter’s Great Red Spot Close-Up]()
Using Hubble Space Telescope data spanning approximately 90 days (between December 2023 and March 2024) when the giant planet Jupiter ranged from 391 million to 512 million miles from the Sun, astronomers measured the Great Red Spot’s size, shape, brightness, color, and vorticity over one full oscillation cycle. The data reveal that the Great Red Spot is not as stable as it might look. It was observed going through an oscillation in its elliptical shape, jiggling like a bowl of gelatin. The cause of the 90-day oscillation is unknown. Credit: NASA, ESA, Amy Simon (NASA-GSFC), Joseph DePasquale (STScI)
This time-lapse movie is assembled from Hubble Space Telescope observations spanning approximately 90 days (between December 2023 and March 2024) when the giant planet Jupiter ranged from 391 million to 512 million miles from the Sun.
Surprising Size Oscillations
“While we knew its motion varies slightly in its longitude, we didn’t expect to see the size oscillate as well. As far as we know, it’s not been identified before,” said Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, lead author of the science paper published in The Planetary Science Journal. “This is really the first time we’ve had the proper imaging cadence of the GRS. With Hubble’s high resolution we can say that the GRS is definitively squeezing in and out at the same time as it moves faster and slower. That was very unexpected, and at present there are no hydrodynamic explanations.”
Hubble monitors Jupiter and the other outer solar system planets every year through the Outer Planet Atmospheres Legacy program (OPAL) led by Simon, but these observations were from a program dedicated to the GRS. Understanding the mechanisms of the largest storms in the solar system puts the theory of hurricanes on Earth into a broader cosmic context, which might be applied to better understanding the meteorology on planets around other stars.
Simon’s team used Hubble to zoom in on the GRS for a detailed look at its size, shape, and any subtle color changes. “When we look closely, we see a lot of things are changing from day to day,” said Simon. This includes ultraviolet-light observations showing that the distinct core of the storm gets brightest when the GRS is at its largest size in its oscillation cycle. This indicates less haze absorption in the upper atmosphere.
This animated diagram shows the position of Earth relative to Jupiter during a period spanning approximately 90 days (between December 2023 and March 2024) when the giant planet Jupiter ranged from 391 million to 512 million miles from the Sun.
Comparative Planetology and Future Predictions
“As it accelerates and decelerates, the GRS is pushing against the windy jet streams to the north and south of it,” said co-investigator Mike Wong of the University of California at Berkeley. “It’s similar to a sandwich where the slices of bread are forced to bulge out when there’s too much filling in the middle.” Wong contrasted this to ![Full Disk of Jupiter]()
Using Hubble Space Telescope data spanning approximately 90 days (between December 2023 and March 2024) when the giant planet Jupiter ranged from 391 million to 512 million miles from the Sun, astronomers measured the Great Red Spot’s size, shape, brightness, color, and vorticity over a full oscillation cycle. The data reveal that the Great Red Spot is not as stable as it might look. Credit: NASA, ESA, STScI, Amy Simon (NASA-GSFC), Joseph DePasquale (STScI)
Anticipating Further Insights
The researchers hope that in the future other high-resolution images from Hubble might identify other Jovian parameters that indicate the underlying cause of the oscillation.
Reference: “A Detailed Study of Jupiter’s Great Red Spot over a 90-day Oscillation Cycle” by Amy A. Simon, Michael H. Wong, Phillip S. Marcus and Patrick G. J. Irwin, 9 October 2024, The Planetary Science Journal.
DOI: 10.3847/PSJ/ad71d1
The results are being presented at the 56th annual meeting of the American Astronomical Society Division for Planetary Sciences, in Boise, Idaho.
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (Read More
This time-lapse movie is assembled from Hubble Space Telescope observations spanning approximately 90 days (between December 2023 and March 2024) when the giant planet Jupiter ranged from 391 million to 512 million miles from the Sun.
Surprising Size Oscillations
“While we knew its motion varies slightly in its longitude, we didn’t expect to see the size oscillate as well. As far as we know, it’s not been identified before,” said Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, lead author of the science paper published in The Planetary Science Journal. “This is really the first time we’ve had the proper imaging cadence of the GRS. With Hubble’s high resolution we can say that the GRS is definitively squeezing in and out at the same time as it moves faster and slower. That was very unexpected, and at present there are no hydrodynamic explanations.”
Hubble monitors Jupiter and the other outer solar system planets every year through the Outer Planet Atmospheres Legacy program (OPAL) led by Simon, but these observations were from a program dedicated to the GRS. Understanding the mechanisms of the largest storms in the solar system puts the theory of hurricanes on Earth into a broader cosmic context, which might be applied to better understanding the meteorology on planets around other stars.
Simon’s team used Hubble to zoom in on the GRS for a detailed look at its size, shape, and any subtle color changes. “When we look closely, we see a lot of things are changing from day to day,” said Simon. This includes ultraviolet-light observations showing that the distinct core of the storm gets brightest when the GRS is at its largest size in its oscillation cycle. This indicates less haze absorption in the upper atmosphere.
This animated diagram shows the position of Earth relative to Jupiter during a period spanning approximately 90 days (between December 2023 and March 2024) when the giant planet Jupiter ranged from 391 million to 512 million miles from the Sun.
Comparative Planetology and Future Predictions
“As it accelerates and decelerates, the GRS is pushing against the windy jet streams to the north and south of it,” said co-investigator Mike Wong of the University of California at Berkeley. “It’s similar to a sandwich where the slices of bread are forced to bulge out when there’s too much filling in the middle.” Wong contrasted this to The researchers hope that in the future other high-resolution images from Hubble might identify other Jovian parameters that indicate the underlying cause of the oscillation. Reference: “A Detailed Study of Jupiter’s Great Red Spot over a 90-day Oscillation Cycle” by Amy A. Simon, Michael H. Wong, Phillip S. Marcus and Patrick G. J. Irwin, 9 October 2024, The Planetary Science Journal. The results are being presented at the 56th annual meeting of the American Astronomical Society Division for Planetary Sciences, in Boise, Idaho. The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (Read More
Anticipating Further Insights
DOI: 10.3847/PSJ/ad71d1