all of our experience in chemistry tells us that chemical characteristics are related to groups of substances, not to individual ones, so the expectation would be that, in principle at least, there would be a group of materials on which the processes of life could be based. So, if life did emerge on some other planet, one based on a different biochemistry from that on earth, can our theory of life offer some insight into how such life would appear? I believe so. My short answer: life on other planets would look exactly like that on our own!
