The question is, what kind of life do we know how to recognize? What kind of life definitely is possible, and what kind is just speculation? In other words: whe

The question is, what kind of life do we know how to recognize? What kind of life definitely is possible, and what kind is just speculation? In other words: where should we look first? The answer is: carbon rich, watery life. Coming up with biosignatures for ourselves is hard enough, coming up with a biosignature for a galactic nebula is unbelievably harder because we have no examples. Extrapolating from one example is much easier than from nothing at all.