Gas Giant Facts

Gas giants are large planets that contain more than 10 times the mass of Earth, they are also known as the Jovian or Outer Planets. Their compositions are mostly gases, such as hydrogen, and small amounts of rocky material (mostly at their cores). The four gas giants in our solar system are Jupiter, Saturn, Uranus, and Neptune.

Find out more about the outer planets by selecting one below.

Facts about the Gas Giants

• The gas and ice giant planets take longer to orbit the Sun because of their great distances. The farther away they are, the more time it takes to make one trip around the Sun.
• The densities of the gas giants are much less than the densities of the rocky, terrestrial worlds of the solar system.
• Gas giants are not all gas. Beneath the heavy atmospheres of these Jupiter and Saturn are layers of molecular hydrogen and liquid metallic hydrogen.
• Uranus has an icy layer over its solid rock core, and covered with a gaseous atmosphere. Neptune has a water-ammonia ocean for a mantle overlying its rocky core.
• The metallic hydrogen layers in Jupiter and Saturn conduct electricity.
• The cores of the gas giants are crushed under tremendously high pressures and they are very hot (up to 20,000 K), while the cores of the ice giants Uranus and Neptune are at 5000K and 5,400K respectively.
• Gas giants have been found around more than a thousand stars by the Kepler mission. These large exoplanets are often referred to by such names as Hot Jupiters, SuperJupiters, and Giant Neptunes.

Gas Giant Sizes & Orbits

Name	Diameter	Distance from Sun	Length of Year
Jupiter	139,822 km	778,340,821 km	11.9 Earth years
Saturn	116,464 km	1,426,666,422 km	29.5 Earth years
Uranus	50,724 km	2,870,658,186 km	84.0 Earth years
Neptune	49,244 km	4,498,396,441 km	164.8 Earth years