The Final Frontier

Saturn

Saturn

Type of Planet

Saturn is a gas giant, meaning a giant planet composed mainly of hydrogen and helium.

Composition/Atmosphere

Like Jupiter, Saturn doesn't have a true surface. The planet is mostly swirling gases and liquids.

Saturn is approximately 75 percent hydrogen and 25 percent helium, with traces of other substances such as ammonia, nitrogen, and oxygen.

At Saturn's center is a dense core of rock, ice, water, and other compounds made solid by the intense pressure and heat. It is enveloped by liquid metallic hydrogen, inside a layer of liquid hydrogen, similar to Jupiter's core but considerably smaller.

The winds on Saturn are the second fastest among the Solar System's planets, after Neptune's.

Planetary Rings

Saturn has an iconic ring system of several hundred rings, made up of dust, rock, and ice. However, it is not the only planet with rings. Jupiter, Uranus and Neptune also have rings.

Size (Diameter), Mass, and Density

Saturn is the second-largest planet in the Solar System, after Jupiter. Earth would fit inside Saturn 764 times.

Saturn is 95 times the mass of the Earth. Together, Jupiter and Saturn hold 92 percent of the total planetary mass in the Solar System.

Saturn is the only planet in our solar system that is less dense than water. The density of Saturn is 0.687 grams per cubic centimeter, compared to Earth's 5.51.

Though Jupiter and Saturn are very close in size, Jupiter is more than three times as massive, and Jupiter's average density is almost twice Saturn's. This is because when the solar system was formed, Jupiter captured more hydrogen and helium in its atmosphere from the solar nebula, increasing its mass and compressing its interior, until its average density was twice Saturn's.

Gravity

Even though Saturn has much more mass than Earth (second in the Solar System only to Jupiter), it also has the lowest density of all the planets in the Solar System. Therefore Saturn's gravity is only 91 percent of Earth's.

Magnetic Field

The magnetic field of Saturn is aligned with the planet's axis of rotation, unlike the fields of Jupiter and Earth.

Temperature

The average temperature on Saturn is a chilly -184 degrees celsius. Most of Saturn's temperature variation is horizontal, rather than between the poles and equator.

Length of a Day (Rotation)

A day on Saturn lasts only 10 hours 13 minutes.

Axial Tilt

Saturn has an axial tilt of almost 27 degrees, which is slightly larger than that of Mars. Seasonal variations are strong on Saturn and each season lasts more than 7 years.

Length of a Year (Orbit)

A year on Saturn lasts 29 and a half Earth years.

Distance from the Sun

Saturn is the sixth planet from the Sun at 888 million miles.