Off-planet is a term used to describe anything that is not on Earth or its immediate atmosphere. There are times when it is necessary to express this concept in different ways. Some synonyms for off-planet include extraterrestrial, interplanetary, outer space, beyond earth, celestial, and cosmic. Extraterrestrial is often used to describe life or technology on other planets. Interplanetary is commonly used to describe travel between planets. Outer space is the general term for everything beyond our atmosphere. Beyond earth and celestial can be used more generally to describe anything in space, while cosmic refers specifically to the universe as a whole.