NASA’s Hubble Telescope reveals Jupiter’s Great Red Spot is oscillating like a 'bowl of jelly'

Jupiter’s Great Red Spot, a storm bigger than Earth, has fascinated astronomers for over 150 years. Thanks to the Hubble Space Telescope, we are gaining new insights into this legendary storm, including its size changes and wobbling movements. Recent observations from the Hubble Space Telescope revealed surprising fluctuations in its size and shape. While scientists were aware that the Great Red Spot moves slightly in its longitude, they didn't expect it to change its dimensions.

The movement of the Great Red Spot has been compared to oscillation of a jelly bowl, challenging previous assumptions about its stability. Understanding the working of the GRS would help the scientists to comprehend weather patterns on Earth and other planets. In this regard, NASA is launching a Europa Clipper mission to look for habitable spots on Jupiter.

Discovering size changes of Jupiter’s Great Red Spot

Scientists have known for a while that Jupiter’s Great Red Spot (GRS) moves a little differently in its longitude. However, they were surprised to discover that its size also changes. Amy Simon, a researcher at NASA's Goddard Space Flight Center, explained that this kind of size change has never been seen before. She noted, “This is the first time we have obtained the right images of the GRS. With Hubble's high-resolution pictures, we can confirm that the GRS is both getting smaller and larger while speeding up and slowing down. This was unexpected, and we currently don’t know why.”

NASA's Hubble Space Telescope regularly checks on Jupiter and other planets far from the Sun through a program called the Outer Planet Atmospheres Legacy (OPAL), which Simon leads. NASA astronomers shared a time-lapse movie of the GRS, combined from the Hubble images.


NASA: Jupiter's Great Red Spot video

Analysing the GRS data gathered from the Hubble telescope

Using data from Hubble collected over about 90 days (from December 2023 to March 2024), scientists studied how the GRS changed in size, shape, brightness, colour, and rotation. They discovered that the Great Red Spot isn’t as steady as it seems. It was found to be wiggling in shape, almost like a bowl of jelly. The reason for this 90-day wiggle is still a mystery.

Simon's team used Hubble to take a closer look at the Great Red Spot to spot tiny changes. “When we examine it closely, we see many changes happening day by day,” Simon said. They found that the bright core of the storm shines the most when the GRS is at its largest, indicating that there is less haze in the upper atmosphere at that time.

As the Great Red Spot speeds up and slows down, it interacts with the powerful jet streams above and below it. Mike Wong, a co-investigator from the University of California, Berkeley, described this as similar to a sandwich that bulges when there's too much filling in the middle.

He pointed out that Neptune’s dark spots can shift wildly in position without strong jet streams to keep them steady. In contrast, Jupiter's Great Red Spot has remained in the same southern location for as long as scientists have been observing it from Earth.

Check out the video of Jupiter's Great Red Spot (GRS) shaking shared by NASA.

What’s next for the GRS?

The research team has been tracking the shrinking of the GRS since the OPAL program started ten years ago. They predict that it will keep getting smaller before finding a stable shape. “Right now, it’s too big for the winds to hold it steady. Once it gets smaller, the winds will better keep it in place,” Simon explained. While they expect the Great Red Spot to eventually stabilize, Hubble has only captured it during one full cycle of size changes.

Researchers are hopeful that more high-resolution images from Hubble in the future will help uncover the reasons behind the GRS's oscillation. The findings from this study will be shared at the 56th annual meeting of the American Astronomical Society Division for Planetary Sciences in Boise, Idaho.

Hubble Space Telescope’s impact on discoveries

The Hubble Space Telescope has been in operation for over 30 years, making groundbreaking discoveries that enhance our understanding of the universe. It is a joint project between NASA and the European Space Agency (ESA). NASA’s Goddard Space Flight Center in Maryland manages the telescope, while Lockheed Martin Space in Colorado supports its operations. The Space Telescope Science Institute in Baltimore oversees the scientific research conducted using Hubble.




Also read: Europa Clipper mission set to explore Jupiter’s ocean moon; here’s all you need to know