We don't have spacecraft? We never will? It's recently been found that Europa sprays out detectable water to great distances, and that traces of amino acid woul

We don't have spacecraft? We never will? It's recently been found that Europa sprays out detectable water to great distances, and that traces of amino acid would be preserved at such temperatures. So we may have one answer re life soon. https://www.theguardian.com/science/2018/may/14/europa-moon-of-jupiter-prime-candidate-for-alien-life-after-water-blast-found https://www.theguardian.com/science/2018/may/14/europa-moon-... If you're assuming that life from, say, Europa, even if we found it, and it was the point of origin for octopi, would have altered so much as to have no genetic or chemical similarity to octopi now, I have no idea what your evidence is for that. To the contrary, there are plenty of very highly evolutionarily conserved proteins, hormones, etc - melatonin is one (it was originally an antioxidant for one-celled creatures.) Refusing to entertain hypotheses by reason of expense isn't science.