Why do scientists think aliens need water?

mainly because here on earth everything living, plant, animal, human ect needs water to survive so naturally theyd look for water or some kind of liquid that would resemble what water does

Life comes in many different forms in many different invoroments.They may exsist in extream tempretures and under extream pressures.They come in different sizes and colours and many breath different gases.Most are sub intellegent who over thousands of years have abdapted to there unique enviroment.Earth is one.There must be trillions of others worlds out there in the universe that support some kind of life.

Over the centuries Mars has lost water and become dry so if there was water then there was a possibility that Martians or aliens could have preserved some water for agriculture since they needed something to eat.This is a theory.Recently traces of pure water have been found on Mars.

well if everythin on earth needs water to survive they would no that if der are planets wit water on them they might have life on them too

Carbon-based life certainly needs water, and lots of it. While it’s possible there is non-carbon based life out there (silicon-based, for example), nobody has come up with a convincing biological chain to support it - certainly not one that doesn’t require water.

So given that the only viable type of life we’re aware of is carbon-based, and given that carbon-based life requires lots of water, the highest return way to look for alien life is to look for places with lots of available water. We might miss something, but we’re more likely to have success than if we had to examine absolutely everything.

that makes a lot of sense xsteffx

well if everythin on earth needs water to survive they would no that if der are planets wit water on them they might have life on them too