Im not sure if this is the right place to ask, the right category, the righr dorum etc. Also im only 15yo so dont explain in too professionam terms please. But ive always wondered this... When people bring up searching for extraterrestial life its always about if water is present on the planet, why is this? I know we live from water and so do fish, where we originally originate from and the bacteria they originated from lived in water but i dont see this as proof. Cant evolution on a planet without water just work with chlorine for example, or an element not even present on earth and thus not known to humanity. Same applies to distance to the sun to have a temperature sweetspot, wouldnt another planet have life evolved to their temperature? I mean we have had animals for ice ages and, well, not ice ages... unless you really are able to prove me wrong here i feel lile we need another planet with this theory proven for it to be sure. Im not trying to start the next flat earth like community but im just trying to understand.