It is more than 10 times the diameter of Earth and more than 300 times its mass. In fact, the mass of Jupiter is almost 2.5 times that of all the other planets combined. Being composed largely of the light elements hydrogen and helium, its mean density is only 1.314 times that of water.Jupiter rotates at a dizzying pace -- once every 9 hours 55 minutes 30 seconds, although the period determined by watching cloud features differs by up to five minutes due to intrinsic cloud motions. The massive planet takes almost 12 Earth years to complete a journey around the Sun. From the Earth, Jupiter can be seen to show a disc with polar flattening, this is due to a very rapid rotation.

Jupiter has a Great Red Spot, an enormous anti-cyclonic system which has lasted for hundreds of years. This hurricane-like storm in Jupiter's atmosphere is more than twice the size of the Earth. As a high-pressure region, the Great Red Spot spins in a direction opposite to that of low-pressure storms on Jupiter; it is surrounded by swirling currents that rotate around the spot and are sometimes consumed by it. Across the disc several bands of dark and light clouds can be seen and the GRS is visible during each rotation.