Flexi Says: The Great Red Spot is Jupiter's most noticeable feature. The spot is an enormous, oval-shaped storm. It is more than three times as wide as Earth! Clouds in the storm rotate counterclockwise. They make one complete turn every six days or so. The Great Red Spot may have been observed as early as 1664 by Robert Hooke (more famous for his observations of cells) and then was systematically observed by astronomer Giovanni Cassini in 1665. It is possible that this storm is a permanent feature on Jupiter, though it is also possible that similar storms come and go. No one knows for sure at this point.
