Which planet is the second-largest in the Solar System?

Which planet is the second-largest in the Solar System? Saturn is the second-largest planet in the Solar System.

Jupiter is the largest planet, while Saturn follows it in diameter, volume, and mass. Saturn has an equatorial radius roughly nine times Earth's and is more than 95 times as massive as Earth, although it contains less than one-third of Jupiter's mass.

Saturn is a gas giant composed mainly of hydrogen and helium. Its famous rings make it look especially large, but the ranking of planets is based on the planet itself, not the full span of its rings. Saturn's average density is unusually low—less than that of water—because its enormous atmosphere contains so much light hydrogen and helium.

Neptune and Uranus are also giant planets, but both are smaller than Saturn. Another common mistake is confusing size with distance: Saturn is the sixth planet from the Sun, not the second planet or the second-farthest planet.