The darkest red part of the spot turns out to be a warm patch inside the otherwise cold storm. The temperature variation is slight: “Warm” in this case translates to -250 degrees Fahrenheit while cold is an even frostier -256 degrees F. But even that difference is enough to create intriguing internal dynamics.
Over the past few decades, astronomers had begun to get a handle on the weather patterns around the Great Red Spot, but not inside of it. Previous measurements have indicated that the spot towered over the surrounding cloud cover, much like supercells on Earth.
Scientists have also noticed that its color changes considerably, but what drives the changes — or the famous ruddy complexion in general — is unclear. A leading theory was that sulfurous molecules from deep in the Jovian atmosphere were being lofted by the storm, exposing them to ultraviolet radiation that would break them apart. The newly freed sulfur atoms would then change color and lend the area its distinctive tinge.
But that might not be the case.
Read More: wired.com