Here's a breakdown:
* Extra: Meaning "outside of" or "beyond"
* Terrestrial: Relating to the Earth
Therefore, extraterrestrial encompasses:
* Objects: Planets, stars, galaxies, asteroids, comets, etc.
* Life: Any life forms that may exist outside of Earth, commonly known as aliens.
* Phenomena: Events or occurrences that originate from space, such as meteor showers, auroras, or cosmic rays.
In simpler terms, extraterrestrial means "from outer space."