For decades now we have been actively searching for evidence of life not of Earthly origin. Our motivation is curiosity, both scientific and otherwise. As tools and techniques have improved, we are getting much closer to our goal, although failure to find life elsewhere would not be probative. It might mean that we aren’t looking in the right place or even that we haven’t recognized the signature of life because we are blinded by our preconceptions.
What is lagging in this effort is a serious analysis of the potential consequences of success. Scientific curiosity has ethical and practical limits. The search itself is probably harmless and is at worst a questionable investment of time and resources. But what if we find life, not just fossils of primordial life but actual living beings? It is very unlikely, some would say virtually impossible, that we would discover intelligent life where we have the current capacity to investigate. Anywhere within our solar system is within practical range, but none of the candidates seem likely habitats for evolved life. Beyond that the immensity of space and sparsity of viable habitats greatly limit feasible investigations. At best we might detect recognizable signatures of life, like the presence of free oxygen on a planet in the habitable zone. This would be intriguing but hardly definitive.
But our solar system harbors several candidates for simple life forms, most notably amongst Jupiter’s moons and even conceivably in subsurface Mars.
We could, and mostly likely will, mount unmanned probes to test these possibilities in the not too distant future. So, back to the question at hand. What if we find life? If we do, it will likely resemble familiar Earthly life in most respects. Why? Because that’s what we would be seeking. Sufficiently foreign life forms would be unrecognizable unless they walked up to our probe and knocked on its door. So, what would be likely consequences to us back on Earth?
Initially, I expect denial and outrage amongst some in the non-scientific community. Life elsewhere challenges many religious beliefs. Personally, I find that odd because surely God could create life anywhere and even divinely inspired scripture could have been deliberately tailored to the intellectual limitations of its receivers. Even for the non-religious, the existence of alien life can be frightening, even if it takes only simple forms. For one thing, we know that simple forms can evolve and that evolution may have occurred beyond our current detection capabilities. Is this a threat, if not now perhaps in the foreseeable future? A special concern is if our probe is sufficiently versatile that it can return samples to Earth for detailed investigation. Should we do this even if we can? What are the risks and are they acceptable for the benefit derived?
My point is that scientific investigation has a life of its own. Once it progresses sufficiently down a path with some evidence of success, stopping it may be very hard. So we should make a serious attempt to answer the questions now. I am no Luddite, but I do harbor concerns that we may not have yet evolved sufficiently to react sensibly to discovery of extraterrestrial life.