Jupiter’s Great Red Spot (GRS) is Jupiter’s most iconic feature. It is an unbelievably huge storm that appears red in color. The mind-blowing fact is that it is big enough to swallow our entire planet, making it the most significant storm in the solar system.
Astronomers have observed Jupiter’s Great Red Spot (GRS), a giant storm big enough to fit Earth inside, for over 150 years. However, new findings from NASA’s Hubble Space Telescope are surprising.
Between December 2023 and March 2024, Hubble captured close-up images showing that the GRS isn’t as steady as it seems. Instead, it wobbles like jelly! These images let scientists create a time-lapse movie showing the GRS’s wiggly movements.
Amy Simon, lead author of the study at NASA‘s Goddard Space Flight Center in Greenbelt, Maryland, said, “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. This is really the first time we’ve had the proper imaging cadence of the GRS.”
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“With Hubble’s high resolution, we can say that the GRS is definitively squeezing in and out simultaneously as it moves faster and slower. That was very unexpected, and there are currently no hydrodynamic explanations.”
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Close-up of Jupiter’s Great Red Spot (8-Panel): consult the Alt Text section of this dialog for a verbal description.
Every year, the Hubble Space Telescope observes Jupiter and other outer planets through a program called OPAL, led by Simon. They recently focused on the Great Red Spot (GRS), the biggest storm in our solar system. By studying this storm closely, scientists hope to learn more about how hurricanes work on Earth and potentially on planets around other stars.
Simon’s team examined the GRS to observe changes in its size, shape, and color. They noticed that the storm changed a lot from day to day. Observations in ultraviolet light showed that the storm’s core shines brightest when the GRS is at its biggest, suggesting there’s less haze in the upper atmosphere at that time.
Jupiter’s great red spot could completely disappear throughout the next 20 years
Co-investigator Mike Wong of the University of California at Berkeley said, “As it accelerates and decelerates, the GRS pushes against the windy jet streams to the north and south of it. 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 compared Jupiter to Neptune, noting that dark spots can move around freely on Neptune because there aren’t strong jet streams to keep them steady. In contrast, Jupiter’s Great Red Spot (GRS) has stayed in one place at a southern latitude, held there by jet streams.
The team has observed the GRS shrinking since the OPAL program started 10 years ago. They believe it will continue to shrink and eventually settle into a more stable, rounder shape.
Simon said, “Right now, it’s overfilling its latitude band relative to the wind field. Once it shrinks inside that band, the winds will really be holding it in place.”
The team thinks the Great Red Spot (GRS) will likely stabilize in size, but Hubble has only tracked it through one full cycle of its changes.
The results are being presented at the 56th annual meeting of the American Astronomical Society Division for Planetary Sciences, in Boise, Idaho.