Alien Here

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

: Modern astronomers use telescopes to scan the atmospheres of distant planets for "biosignatures"—gases like oxygen and methane that might indicate life. In science, an "alien" is any organism that

: In a legal context, an alien is a person in a country who is not a citizen of that country. Outside of space, "alien" has a specific legal

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

The most famous "alien" in the world is the Xenomorph from the 1979 film Alien .

: Scientists suggest looking at non-human intelligence on Earth—like octopuses, crows, or bees—as a way to prepare for how truly different alien minds might be. 2. Legal and Societal Definitions

: NASA uses a multi-level scale to verify alien life. Reaching "level seven" would mean ruling out all non-biological explanations and having secondary evidence, like a radio signal.