Which planet has the Great Red Spot?

The Great Red Spot is on Jupiter. It is a vast, persistent high-pressure storm in Jupiter’s southern hemisphere and the most recognizable feature in the planet’s atmosphere.

Unlike a hurricane on Earth, the Great Red Spot is an anticyclone: its winds circulate counterclockwise when viewed from above Jupiter’s south side. The storm is embedded between powerful atmospheric jet streams, which help keep it organized. Because Jupiter has no solid surface beneath its clouds, there is no land friction to weaken it in the same way terrestrial storms lose energy.

The source of its red-orange color remains uncertain. Chemical reactions involving sunlight and compounds drawn upward from deeper atmospheric layers may contribute to the coloration. The storm has also been shrinking over modern observation, although it remains wider than many planets’ major surface features.

A historical puzzle surrounds its age. A red spot was recorded in the 17th century, but observations stopped for decades. The modern storm has been continuously observed since 1831, so scientists are cautious about claiming that it is definitely the same feature seen by earlier astronomers.