What is the biggest planet?
Jupiter is the biggest planet in our solar system. It is about 11 times wider than Earth and more massive than all the other planets combined.
Jupiter's diameter is about 140,000 kilometers. More than 1,300 Earths could fit inside it, and its mass is about 318 times Earth's. It is a gas giant made mostly of hydrogen and helium, with no solid surface to stand on.
Jupiter spins faster than any other planet, completing a day in under 10 hours. This fast rotation stretches its clouds into colorful bands. The Great Red Spot, a storm wider than Earth, has been raging for at least 150 years.
Moons and missions
Jupiter has nearly 100 known moons. The four largest, Io, Europa, Ganymede and Callisto, were discovered by Galileo in 1610. Ganymede is the largest moon in the solar system, and Europa may hide a liquid ocean under its ice. NASA's Juno spacecraft has orbited Jupiter since 2016.
Did You Know?
Jupiter's strong gravity may help protect the inner planets by pulling in or deflecting some comets and asteroids.