Alien

In science, an "alien" is any organism that did not originate on Earth.

: In the United States, once an alien gains admission and develops ties, their constitutional status changes, according them a "generous and ascending scale of rights". In science, an "alien" is any organism that

The most famous "alien" in the world is the Xenomorph from the 1979 film Alien . : The term is often used metaphorically in

: The term is often used metaphorically in literature to describe the feeling of being "not quite one of us" or surviving in a foreign land. 3. Pop Culture and Science Fiction Outside of space, "alien" has a specific legal

: Modern astronomers use telescopes to scan the atmospheres of distant planets for "biosignatures"—gases like oxygen and methane that might indicate life.

Outside of space, "alien" has a specific legal meaning regarding human movement and national borders.

ArtI.S8.C18.8.7.2 Aliens in the United States - Constitution Annotated