This is along the line of what I had proposed with SETINE - Search for Extra-Terrestrial Intelligence Near Earth The idea that if they are out there, then they must be out there.
If there is life, the odds are it's 100's millions of years ahead or behind us.
I mean the universe is something like 14 Billion years old. We are to believe life started on earth 4 Billion years and here we are out of 4 billion years it's really the past 100 that Earth finally has technology and the ability for it's life to influence the universe beyond the surface of this one planet?
The odds of finding a race that's a few 1000 years ahead of us is slim, very slim. Even a few million is slim. Given our changes in the past 100,000 years, or even the past 100 it next to impossible to imagine where us Humans and our machine will be in 100,000 years. Our descendants, I expect, would appear very alien to us. So much so it may be hard to prove or even convince people that we were ever even related.
So with such a difference in Time/Evolution a visitor might not even be recognized by most and would just be crazy talk by those who are willing to share what they saw.
Another thing that occurred to me is life forms surviving and evolving in the vacuum of space could be possible. It may not even be required to be intelligent such as John Glenn's fireflies.