posted on Jul, 10 2003 @ 02:12 PM
The Arnold sighting is considered the first 'modern era' one...and, in essence, serves as the 'first' sighting because it's the oldest one that
we can really study. During WW2 there were several sightings of "Foo Fighters" (little balls of light that followed bomber formations), but many
people think those were electromagnetic disturbances caused by the aircraft themselves (remember, in WW2 you had 1000+ planes flying in groups at an
altitude where cloud to cloud lighting originates).
In the 1890s there were several sightings of "Mystery Airships" in the midwest.
And, during the late middle ages/early modern period, there were several reported "battles" in the sky between weird objects...
Prior to Arnold, there are every few sightings in the 'nuts and bolts' sense... Many of the pre-modern things (save for the airships) could be
interpreted as just religious epiphanies.
If you go to NICAP's website, they have a calender/catalogue of all the early sightings.