Most likely explanation - they are our’s developed by our skunkworks and sightings are test flights.
Much less likely, but cannot be entirely discounted - they are ET’s from other galaxies or other dimensions. Think the Drake equation on this one. 100% certainty there is life on other planets.
The question is - are they so far technologically advanced that they can travel light years, and if so, would it not be feasible that IF they are so technologically advanced that they also have the ability to hide their presence and communications from us? Imagine time travelling Navy Seals with their comms and gear running a covert mission during the Revolutionary War. The Redcoats would be absolutely clueless as to their presence.
Most likely explanation - they are our’s developed by our skunkworks and sightings are test flights.
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Yep that explains all of the sightings going back hundreds of years - it was the SkunkWorks with time traveling UAPS.
The general consensus (for a while now) is that these things seem to be moving in and out of our reality from another dimension and have, perhaps, always been here on Earth.
If you read about this at some depth, you will find that your explanation is way off the mark. Those beings have something to do with our very existence and trajectory through history.
They are here and have been here since before homo sapiens crawled out of the caves.
https://thejournalofcosmology.com/Puthoff.pdf