Jupiter has the Great Red Spot, the Solar System’s largest known storm.
The Great Red Spot is a gigantic anticyclonic storm in Jupiter’s atmosphere. It rotates counterclockwise in Jupiter’s Southern Hemisphere and is wider than Earth, although its size has changed significantly over the centuries. The storm’s reddish colour varies and may result from chemical compounds altered by sunlight in Jupiter’s upper atmosphere.
Observers have recorded a persistent oval feature in this region since at least the nineteenth century. The exact relationship between earlier observations and the modern Great Red Spot is debated, but the storm has certainly endured for many decades. NASA’s Voyager spacecraft photographed it during flybys in 1979.
Jupiter’s atmosphere is composed mostly of hydrogen and helium and contains powerful jet streams. Unlike a hurricane on Earth, the Great Red Spot does not move over a solid surface and is not fueled by warm ocean water. It is maintained by Jupiter’s atmospheric circulation.
The storm has generally shrunk since systematic measurements began, but it remains a defining feature of the giant planet.