The long axis of this characteristic storm is about 150 miles (240 kilometers) shorter now than it was in 2014. Recently, the storm had been shrinking at a faster-than-usual rate, but the latest change is consistent with the long-term trend. The Great Red Spot remains more orange than red these days, and its core, which typically has more intense color, is less distinct than it used to be.
The Hubble images also revealed a baroclinic waves in Jupiter’s North Equatorial Belt that NASA’s 1977 Voyager 2 mission previously captured. The wave, NASA explains, is similar to what we sometimes see on Earth when cyclones are forming. “Until now, we thought the wave seen by Voyager 2 might have been a fluke…As it turns out, it’s just rare!” explained NASA JPL researcher Glenn Orton.