The planet with the largest storm known as the Great Red Spot is Jupiter. This massive storm, larger than Earth itself, has been raging for at least 350 years, possibly much longer. The Great Red Spot is a high-pressure region producing an anticyclonic storm characterized by its distinct reddish color. It features swirling winds that can reach speeds of around 400 kilometers per hour (about 250 miles per hour). The storm's persistent nature and size make it one of the most fascinating features of our solar system, and scientists study it to better understand atmospheric dynamics on gas giants like Jupiter.