I've always been kind of fascinated about the Nuremberg event back in 1561:
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The main reason is because, unlike those paintings that have nothing to do with UFO's supposedly featuring them, in this woodcut the artist is actually attempting to show what hundreds of people witnessed.
(And yes, it looks like a really bad acid trip, but if mass ergot poisoning is the only explanation detractors can give then I ask you how a drug/poison can give the same exact delusion to countless people all over a city.)