The Great Re Spot is a persistent anticyclonic storm on the planet Jupiter, 22° south of the equator, which has lasted for at least 178 years and possibly as long as 343 years or more. The storm is large enough to be visible through Earth-based telescopes. It was probably first observed by Giovanni Domenico Cassini, who described it around 1665. The spot has been noticeably red at times throughout its observed history, yet has not been appreciably red in the visible spectrum since a rather brief period in the mid 1970s.