Well quite a few of the tens of thousands who went to see the final "show" actually were there to "debunk" it, as others had in the preceding months but failed to and the only photo I have seen of the event seems to show something looking quite "UFO" ish.
Also strange effects were observed from other villages/locations over the place where the show took place, these villages were upto some miles distant away so it was something tangible and not all hysteria unless of course if hysteria can produce something tangible but that is a topic on its own :? .
The weather on the day of the last and best show were actually quite cool and overcast with rain, until the show started. Certainly I am sure some of the "faithful" who were there would have been open to suggestion.
The whole series of events during that year in Fatima make for some really weird stuff especially when you dissassociate the religious trappings. The "dancing sun " at the final show moved like a classic 50'sf ufo falling like a leaf, the other movements of the sun were obviously not the sun it moved far too much for any sort of refractive trick, and to some descriptions looked like a ufo. According to some eyewitness reports human looking beings were observed in the "Sun" ( Which was reported as quite unsunlike during the show).
The humanoid who appeared to the "seers" did not seem very human from the original descriptions and was embellished quite a bit to look like a religious trademark. There is a pretty good book or two on these events from a "ufo" perspective well worth reading. "UFO" and "fatima" in a search should bring it up.
Peoples soaked clothes dried out in minutes once the "Sun " was doing its show At least one man observed the "Sun" through binoculars.anyone who did that at high noon and clear sky would if the pain did not stop him blind himself in a very short time! Well this man didn't but then I do not think it was the sun he was looking at!
http://en.wikipedia.org/wiki/Miracle_of ... _the_event
Oh back on topic another good UFO encounter was the B29 over the gulf of mexico visual and radar observation of multiple ufo's travelling at speeds upto 9000MPH 1950's again though and again you will have to search but i think a fairly strong unknown.