Earlier quoted context omitted.
All entertaining to speculate, but it's classic human-centered thinking to suppose that aliens would be regularly appearing a few thousand feet or so from us, but never ever anywhere in the rest of the billions of miles of our solar system and everywhere else in between here and wherever they came from (in addition to their conveniently never appearing within clear view of regular citizens' phones or cameras and neve…
In this context, it actually makes sense to think in a human-centered way. Consider how many planets are capable of supporting intelligent (as we know it). Now suppose we detect evidence of industrial behavior (certain pollutants, nuclear detonation, etc). Would we not laser focus on that one planet and observe it with everything we have - including sending reconnaissance drones? Furthermore, would we not want to avo…
yet we have thousands of reports of UFO sightings (the vast majority seem to be in the US for some reason). So the aliens who can travel here in...assuming they come from a nearby solar system 4 light years away, and they are arriving as a result of observing "pollutants and nuclear detontations", meaning if they started traveling in 1950 (upon receiving the light from the first nuclear detontation in 1945) and UFO sightings picked up by the 1960s they traveled 4 light years in about 10-15 years, and can be "undetectable" except.... for thousands of non-confirmable sightings per year.
I think the aliens aren't going to visit us until Zefram Cochrane achieves his first warp flight.