I was at pains to point out that I wasn't after numerically-stated odds. The point here is that the evidence we have is stacked against your aliens. There has never been any form of communication with aliens, in spite of alleged frequent visits to our planet by UFOs. There is no evidence of any effect "they" have ever had on us. There has never been a single really convincing photo or video of a UFO or an alien. I pointed out the implausibility, according to the laws of physics, of their visiting us. On the other hand, your "spaceships" were perfectly feasible human constructions. We have built airborne craft of all shapes, sizes, colours and materials. Nothing you saw was humanly impossible, or even technically difficult to achieve. Your only evidence ids that they were unexpected and unfamiliar. We have to proceed through this complicated life somehow, and one good ploy is to go, with all appropriate doubts of course, with what are the most likely explanations, for now, for things, given the evidence we currently have. It's only you rattling on about "the truth," not me.