Great Red Spot

The Great Red Spot is a vast anticyclonic storm in Jupiter’s atmosphere. It is reddish and has been observed for centuries, though its size and appearance change.

Anticyclone: A rotating high-pressure weather system whose winds circulate opposite to a cyclone’s. The Great Red Spot is a giant anticyclone, with winds circulating around a high-pressure center.
Cassini's Jupiter observations: Observations of Jupiter made by Giovanni Domenico Cassini and other astronomers in the seventeenth century. A dark oval recorded in 1665 is sometimes linked to the Spot, but its identity remains uncertain.
Voyager 1: A NASA spacecraft that flew past Jupiter in 1979 and returned detailed images of its atmosphere. Its images captured the Spot at a much larger size than seen in recent decades.
Chromophores: Molecules or particles that absorb particular wavelengths of light and give materials their color. Photochemical chromophores are a leading explanation for the Spot’s reddish hues.
Great Dark Spot: A large dark atmospheric vortex observed on Neptune by Voyager 2 in 1989. It resembled a giant anticyclone but disappeared before later observations, unlike Jupiter’s persistent Spot.
Jupiter's jet streams: Fast atmospheric currents that flow eastward or westward in bands on Jupiter. The Spot is confined and shaped by strong jet streams on either side.
Samuel Heinrich Schwabe: A German astronomer who observed Jupiter’s Great Red Spot in the nineteenth century. His 1831 drawing is among the earliest unambiguous records of the present storm.
Voyager 2: A NASA spacecraft that flew past Jupiter in 1979 after Voyager 1. Its close-up observations helped reveal the storm’s cloud structure and surrounding atmospheric flow.
Jupiter's ammonia clouds: Upper cloud layers in Jupiter’s atmosphere formed from ammonia ice particles. The exact cloud chemistry that produces the Spot’s visible color remains unsettled.
Jupiter's White Ovals: Large pale anticyclonic storms on Jupiter, including vortices that later merged into Oval BA. Their mergers and color changes provide a contrast to the Spot’s long-lived, reddish vortex.

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