<P> The Great Red Spot is a persistent high - pressure region in the atmosphere of Jupiter, producing an anticyclonic storm 22 ° south of the planet's equator . It has been continuously observed for 188 years, since 1830 . Earlier observations from 1665 to 1713 are believed to be of the same storm; if this is correct, it has existed for at least 350 years . Such storms are not uncommon within the turbulent atmospheres of gas giants . </P> <P> The Great Red Spot may have existed since before 1665, but the present spot was first seen only after 1830 and well - studied only after a prominent apparition in 1879 . The storm people had seen in the 1600s may have been a different storm than the one we see today . A long gap separates its period of current study after 1830 from its seventeenth - century discovery; whether the original spot dissipated and reformed, whether it faded, or even if the observational record was simply poor, are all unknown . </P>

What is the big red dot on jupiter