Case description
On April 24, 1959, Hélio Aguiar was riding a borrowed motorcycle along the coast at Piatã, near Salvador, Bahia, when he noticed a dark point over the sea. It grew larger and resolved into a metallic disc. His motorcycle reportedly stopped as the object approached.
Aguiar described a domed top, openings around the edge and markings or projections underneath. He took photographs while the object manoeuvred, including changes of attitude and hovering. During this sequence, he said that he felt pressure in his head and an urge to write something down, followed by an interruption in awareness.
When he regained his bearings, he found himself leaning over the motorcycle with a pencil and a piece of paper. On the paper was a message in Portuguese, in his handwriting, warning against nuclear tests for warfare. He said he did not remember composing it.
Aguiar then took the film to a friend at a military office. Four images were reported when it was developed, including one he did not remember taking. The photographic and written materials became the basis for subsequent discussion of the encounter; the source does not describe a witnessed occupant or an ordinary spoken conversation.
