If you hear “extraterrestrial,” what do you picture? Google it, and chances are you’ll find at least one visualization of a humanoid alien, maybe even waving at the camera.
The idea that extraterrestrials, specifically intelligent ones, might exist has long captured our fascination. Its longevity across the ages indicates a burning question: Is something or someone else out there?
The word itself is quite simple. “Extra” means outside of, and “terrestrial” means the Earth. Add that together, and it means something from outside of our Earth. Because it’s so general, “extraterrestrial” can describe other cosmic objects beyond our immediate backyard, such as space dust or meteorites.
In the context of life, “extraterrestrial” would mean an organism originating and capable of surviving outside of Earth.
“It’s a broad term that brackets a whole range of methods for looking for life in different locations and different environments,” says Chris Impey, a university ...
