The largest planet in our solar system is Jupiter. Jupiter is a gas giant and is significantly more massive and larger in size than all the other planets in our solar system. It has a diameter of approximately 139,822 kilometers (86,881 miles) and a mass that is more than 300 times that of Earth. Jupiter is known for its striking bands of clouds, its Great Red Spot (a massive storm), and its numerous moons, the largest of which is Ganymede.