How easy is it to have different mixtures of substances that lead to similar enough absorption apectra that they are indistinguishable with the available resolution and sensitivity?
There’s no reason I can see to assume we’ve discovered even 1% of the elements out there... we’re also just seeing a trace of something that was there hundreds of years ago right? We’ve never even gone out there to see if our assumption that only water cause this kind of reflected light is even correct.
