Monitoring the PH levels of various water reservoirs in the plant was one of the duties of Moreira. In the night of March 1997, he spotted a large saucer-like object when he went outside to take some readings. He said that the mysterious object silently hovered 20 meters away from him.
Moreira described the object as dark grey in colour with no windows or some sort of openings. He also did not see a single light from the craft. He added that the craft was wide and tall as a house.
He tried to look around to see if there was someone near the area. When he did not see anyone, he ran as fast as he could and called the security desk using a telephone. A young man answered him and Moreira told the man to come down. Moreira then went back outside and the craft disappeared. He said he was only gone in the area for about 10 to 15 seconds. The young man who saw his face said that he believed in him.
Moreira believed that he saw an alien craft and they came for a reason but whatever the reason was, he still does not know until now.