Why the Great Red Spot on Jupiter 'jiggles' in recent NASA study
A recent observation of one of Jupiter's most prominent features – the Great Red Spot – reveals the phenomenon is not quite as stable as it seems.
Images of the giant red storm, captured over 90 days from December 2023 to March 2024 by the Hubble Space Telescope, were compiled and aligned into a time-lapse that shows the storm's elliptical shape oscillating and jiggling. The cause of the oscillation was not identified.
"This is really the first time we've had the proper imaging cadence of the (Great Red Spot)," said Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study published in The Planetary Science Journal. "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."
What is Jupiter's Great Red Spot?
The Great Red Spot is a gargantuan, high-pressure vortex called an anticyclonic storm that has been raging in Jupiter's southern hemisphere for at least 350 years. The storm's physical width has varied in roughly 150 years of observation, but it's believed to be more than 10,000 miles wide – more than enough to contain the entirety of Earth.
The storm, believed to be wedged between jet streams in the gas giant's upper atmosphere, produces counter-clockwise winds that are believed to range from between 268 mph to more than 400 mph.
"While we knew its motion varies slightly in its longitude, we didn't expect to see the size oscillate. As far as we know, it's not been identified before," Simon said.
SOURCES Space.com, NASA Goddard Space Flight Center