What is Jupiter’s Great Red Spot?

This huge anticyclone sits in Jupiter’s southern hemisphere, with winds reaching around 430 km/h or more. Continuous observations date back to at least 1831, and some astronomers think a spot seen in the 1600s may have been the same storm, though a 2024 study suggested it was a different one. The storm has been shrinking: in the late 1800s it was around 40,000 kilometres wide, and today it is roughly 16,000 kilometres, still wider than Earth. Its reddish colour may come from chemicals broken down by sunlight. NASA’s Juno spacecraft found it extends about 300 to 500 kilometres deep.