Lying 700 million kilometers from the Sun, Jupiter is by far the biggest planet in the solar system. It is 143,00 kilometers across, greater than all the planets combined. Its thick atmosphere is composed of hydrogen and helium, with small amounts of other compounds lending the clouds their colours. The striped cloud formations are caused by winds travelling at over 180 kilometers per hour, whipped up the planet's extremely rapid rotation (A Jovian day only lasts 10 hours) and stirred by heat from within. This 1979 Voyager 1 image shows the Great Red Spot, a storm system several times larger than Earth, and Jupiter's nearest moon, Io (center, visible in front of Jupiter).