What are the main constituents of the Jovian planets?

Hydrogen and helium are the main constituents of the Jovian planets. The planets also contain large amounts of ammonia, methane and water.

The Jovian planets include Jupiter, Saturn, Uranus and Neptune. They all feature a little different composition and chemical makeup, but none have much in the way of solid surfaces. All of these planets also contain dense cores and rotate much more rapidly than the other planets in the solar system. Each one of the Jovian planet also contains moon and rings. The other planets are referred to as "terrestrial" planets. Earth and Mars are the only two terrestrial planets that contain moons.