Home » Sciences » Geology » Jupiter: The Heaviest Planet of Solar System. Jupiter is the heaviest planet of the solar system and the weight of Jupiteris 85 earth pounds. Earth weighs 6,000,000,000,000,000,000,000,000 (6E+24) kilograms. It is also the largest planet with biggest diameter of 143,000 km. The mass of Jupiter is 1.8981 x 1027 kg, volume is 1.43128 x 1015 km3, surface area 6.1419 x 1010 km2, and a mean circumference of 4.39264 x 105 km.