“Likelyhood...zero”
Opinion? Informed opinion?
Or, empirical fact?
Not sure why you ask, but I think I am on record as not believing in ET nonsense, though it makes great movie material.
Now, do I believe that there is the possibility of life elsewhere in the universe. Maybe. Do I believe there is or has been intelligent life elsewhere in the universe, maybe. Do I believe that we will ever encounter it, only of we go there and find it, and the odds that we find it are infinitely small.
Part of my belief has to do with my belief in how we got here ourselves. I don't believe in evolution, life from nothing. I believe there is enough evidence to point to intelligent design that we are God's planned creation. Please don't confuse that with the strict creationist belief that history is only 6000 years old. God has left us evidence that the universe was created some 15 billion years ago. Genesis speaks in Gods time scale, not mans interpretation of it.
Does all that mean God didn't create life somewhere else? I have no idea, but I think He created the huge barrier of space to keep us in our own playgrounds for a reason. If He means otherwise, we will find that out in His own good time.