Answer: Jupiter is the fifth planet from the Sun and the largest planet in the Solar System. It is two and a half times the mass of all the other planets in the Solar System combined. With a radius of 43,440.7 miles, Jupiter is 11 times wider than Earth. If Earth were the size of a nickel, Jupiter would be about as big as a basketball. Its atmosphere is mostly hydrogen and helium, and its iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years. More than 1,300 Earths would fit inside Jupiter.