Cool Facts
Massive hydrogen worlds. Gas giants are enormous planets that don't have a solid surface. Instead, they're mostly made of hydrogen and helium, the same gases that make up stars.
Jupiter and Saturn. Our solar system has two gas giants: Jupiter, the largest planet, and Saturn with its beautiful rings. Both are much bigger than Earth.
Different from ice giants. Scientists used to call all giant planets by the same name, but in the 1970s and 1980s they realized Uranus and Neptune were different. Those planets are called ice giants because they're made of heavier, frozen materials instead of just hydrogen and helium.
Almost all gas. If you could somehow stand on a gas giant, you'd sink right through because there's no hard ground to stand on, just thick layers of swirling gas.