Old UFOs vs New UFOs

Earlier here we’ve posted a view about the evolution of UFOs.

But there seems to be a rather abrupt change in how the phenomenon appears to observers.

During older periods with “historical” references to UFOs, the things either took persons up in the heavens (Enoch, Elijah), inter-acted with humans (Ezekiel), or fought in the skies (the vimanas of ancient India, the Basel, Switzerland battle of 1566).









While there is a lacuna of sorts after that Basel sighting, UFOs appeared as mysterious dirigible-like airships in the 1890s, with sporadic sightings of disk-shaped “craft” up to the 1950s, when UFOs or flying saucers were almost ubiquitous.





See this paper about the 1954 UFO wave – a PDF.

Saucers were debarking creatures:



Saucers were, allegedly, shooting ray guns at observers and abducting them or giving them rides into outer space:



Saucers were skirting the airways of Earth with pronounced chutzpah:



Then a UFO drought began, in the late 1970s, 1980s, 1990s, until today when UFOs appear as triangular or rectangular craft, never descending to the ground, never exuding beings or creatures of any kind, and never coming into proximity with humans.



What has happened to the phenomenon? Why the alterations in appearance and behavior?