Here is what bothers me about UFO sightings...(I understand that the reports may come from serious, level headed observers). We (the Earth) are not near anything. Both galactic and intergalactic travel involve distances that are pretty much unimaginable and transit times that match. And yet....there have been reports of UFOs since before last century. No contacts. Since the period of observation here on Earth is over a century, it is reasonable to assume that - if there are real ships - they are from different sources (either that or that mother ship has been hanging around unnoticed for quite a while)
Is the Earth a tourist stop?
Given the vastness of space and the time involved in travel, the ships all would have to have left at about the same time and decided to make their way to an Earth that was far, far less advanced than it is now. So...as noted in another post...no emissions to home in on.
Once here....where are they? Where do they go once they have whizzed by? Mother ships (a Hollywood term). Undetected for decades? Transit to and from the MS undetected?
I do not think so.
How many here are familiar with the SETI program run out of UC Berkeley since 1999 - the search for extraterrestrial intelligence. 20 years and no contacts. Are we to believe that all of the UFOs slipped by?
note:
https://setiathome.berkeley.edu/. A useful thing to do with your computer.