Home > Encyclopedia of Science > Jupiter

• The planet's origin
• Discoveries by the Galileo probe
• Comet Shoemaker-Levy 9 collides with Jupiter

Jupiter, the fifth planet from the Sun, is the largest and most massive planet in our solar system. It is 1,300 times larger than Earth, with more than 300 times the mass of Earth and 2.5 times the mass of all the other planets combined. It has a diameter over 88,000 miles (142,000 kilometers), more than eleven times Earth's diameter of 7,900 miles (12,700 kilometers). Lying about 480 million miles (770 million kilometers) from the Sun, Jupiter takes almost 12 years to complete one revolution.

With its 28 moons, Jupiter is considered a mini-solar system of its own. Before the twenty-first century, astronomers believed Jupiter had only 16 moons. But a rash of discoveries...