why are we so certain that water and oxygen are required for alien life?

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We’re assuming that alien life requires the same things we do, why?

In: Biology

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Anonymous 0 Comments

Also, Oxygen is not required as it is a “toxic” byproduct of sunlight-based cellular respiration. However, free oxygen is quite reactive and readily absorbed by rocks and in the water. What does that mean? It means finding free oxygen in an atmosphere is a very good sign that something is *creating* more oxygen on a constant basis and that has a fairly good chance of being some sort of plant life.

Secondly, Oxygen cellular reactions are much higher energy than CO2 based. If the planet evolved in a similar manner to ours we might find higher order creatures like animals.

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