Gas giant Gas giant A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are sometimes known as failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" was originally synonymous with "giant planet", but in the 1990s it became known that Uranus and Neptune are really a distinct class of giant planet, being composed mainly of heavier volatile substances (which are referred to as "ices"). For this reason, Uranus and Neptune are now often classified in the separate category
Planets and habitats of the Night's Dawn trilogy with Dr. Mzu's Neutronium Alchemist during the brief war between the two. They managed to prevent the attack and retaliated with an antimatter warhead strike against Garissa, killing the entire population. Omuta was placed under complete isolation for thirty years in punishment for the attack. Capital world of the Japanese Empire, and the home port of the Confederation's fourth largest fleet. A ringed gas giant in Earth's Solar System with many habitats, including Romulus and Remus (see below). A gas giant planet in the same system as New California, home to 30 Edenist habitats. The Capone Organization attempted to take