system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does the search for extraterrestrial life revolve around water?

I mean, surely scientists understand that life as WE know it can't be the only form of life out there...
gpt
As far as we know, all life requires water. Until we have evidence that there are types of life that don't require water, we'll search for what we know.

You can't find something if you don't know what you're looking for.