Translation guide
A large planet composed mainly of hydrogen and helium, like Jupiter or Saturn. In Japanese, the standard term is 巨大ガス惑星, but the loanword ガスジャイアント is also used in astronomy contexts.
Refer to a planet that is a gas giant in scientific or educational contexts.
The most common and standard Japanese term for 'gas giant' in astronomy. Literally 'giant gas planet'.
Jupiter is a gas giant.
Shortened form meaning 'gas planet'. Sometimes used, but can be ambiguous as it may refer to any planet with a thick gas atmosphere.
Loanword from English, used in some scientific and popular science contexts. Less common than 巨大ガス惑星 but understood.
There are two gas giants in the solar system.
Gas planets do not have a solid surface.