They were probably justly forgotten, by everyone but UFO fanatics. Notice that he assumes the events were “well documented and witnessed” without giving us any details.
Sprites are large-scale electrical discharges that occur high above thunderstormclouds, or cumulonimbus, giving rise to a quite varied range of visual shapes flickering in the night sky. They are triggered by the discharges of positive lightning between an underlying thundercloud and the ground.
and this spectacular phenomenon.
Can you imagine a what this must have looked like to early man? I’m sure, even today, to many uninformed minds these are UFOs or signs of God.
But in reality, these are merely huge electrical discharges, caused by mathematically specific atmospheric conditions.