Notice that these stories seem to begin around 1746 - 48 or thereabouts. That would have been when people flying around in piston-engined aircraft started seeing jets for the first time.
Sorry, that’s 1946 - 1948 or so.
Really? That must have been around the time that France was challenging the British for North America. Before Braddock and Wolfe!
Methinks they we’re all just Franklins kites at the time....
Some hypothesize the time correlates pretty closely with the detonation of the 1st atomic bomb. Understanding, and applying, atomic fission would be a notable step in a species scientific advancement. This 'tripwire' event was monitored by aliens, as the theory goes, who have since dropped by to observe.