There is actually a lot that can be gleaned from the lack of observable evidence to the contrary. We have a hard data point in ourselves. We know life is possi

There is actually a lot that can be gleaned from the lack of observable evidence to the contrary. We have a hard data point in ourselves. We know life is possible. The only question is how common is it. Right now the evidence says "Rare". Now the task is to figure out why it's rare instead of common, and exactly how rare it really is. This means gathering data, forming theories, making predictions, and comparing expectations to new data. This seems like perfectly reasonable science to me.