The red dot on Jupiter is a storm known as the Great Red Spot. It has been observed since at least 1831 and is the largest storm in the Solar System. The Great Red Spot is a giant anticyclone larger than Earth and has been known to last for at least 350 years. It is driven by the jet streams on the planet and winds can reach speeds of up to 432 kilometers per hour. The color is thought to be caused by trace amounts of phosphorus and sulfur reacting with sunlight to produce red and orange hues.