What color is Jupiter's Great Red Spot?

Jupiter’s Great Red Spot is red, although its appearance can range from brick-red and orange to pale salmon or nearly white. The name refers to its characteristic reddish color rather than a perfectly fixed shade.

The Great Red Spot is a gigantic, persistent high-pressure anticyclonic storm in Jupiter’s atmosphere. It lies about 22 degrees south of the equator and rotates counterclockwise. Because Jupiter has no solid surface, the storm is not slowed by ground friction in the way an Earth hurricane eventually is; powerful jet streams help confine it.

Scientists still do not know exactly why the spot is red. Leading ideas involve sunlight-driven chemistry in the upper atmosphere, where ultraviolet radiation acts on compounds such as ammonia and acetylene, producing complex reddish materials. Its color changes over time as atmospheric conditions change, so photographs may show noticeably different hues. It should also not be confused with Oval BA, a smaller Jovian storm sometimes nicknamed the Little Red Spot, or Neptune’s separate Great Dark Spot.