The largest planet in our solar system is Jupiter. This gas giant is known for its vast size, having a diameter of about 86,881 miles (139,822 kilometers) and containing more than twice the mass of all the other planets combined. Jupiter is primarily composed of hydrogen and helium, and it has a distinctive appearance characterized by its Great Red Spot, a massive storm larger than Earth. Additionally, Jupiter has an extensive collection of moons, with over 79 confirmed, including the four largest known as the Galilean moons: Io, Europa, Ganymede, and Callisto. Its immense gravitational pull has important implications for the solar system's structure.