Jupiter has the Great Red Spot, a giant atmospheric storm that has existed for centuries. The oval-shaped storm is located in Jupiter's southern hemisphere.
The Great Red Spot is an anticyclone, meaning its circulation turns opposite to that of a cyclone in Earth's northern hemisphere. Winds around its edge can reach hundreds of kilometres per hour, and the storm's reddish colour may come from complex chemical reactions in Jupiter's atmosphere.
Astronomers have observed the feature since at least the 17th century, although the modern storm may not be identical to every earlier observation. Its size has changed over time and has generally shrunk since measurements became systematic.
Jupiter is the largest planet in the Solar System and is a gas giant made mainly of hydrogen and helium. The Great Red Spot is not a solid surface feature; it floats within the planet's deep, rapidly moving clouds. Other planets, including Neptune, also have powerful storms.