We’re assuming that alien life requires the same things we do, why?
In: Biology
Have you ever heard the phrase “life, as we know it” in a sci-fi show?
We only know of life on one planet. All the life *that we know of* needs liquid water in some form. We do already know of [life that doesn’t need oxygen.](https://en.wikipedia.org/wiki/Anaerobic_organism)
Scientists are very interested in finding a planet with water and oxygen for two reasons. First, water means that life *like Earth life* could exist there. Second, oxygen likes to combine with other things, and that means that if a planet has a lot of free oxygen, there’s likely something actively separating the oxygen and releasing it back to the air. The best candidate *that we know of* is life. This means that if you’re looking for life similar to Earth life, a planet with water and oxygen is a good place to start looking.
There *could* be all kinds of other life out there. We don’t know. But, that also means that we don’t know what to look for or where to look.
Latest Answers