A fourteenth century fresco of the Madonna and Child depict on the top right side the image of a UFO hovering in the distance. A blow up of this fresco reveals tremendous details about this UFO including port holes. 

It seems to indicate a religious involvement between UFO’s and the appearance of the Christ Child. This painting is called “The Madonna with Saint Giovannino”. It was painted in the 15th century by Domenico Ghirlandaio (1449-1494) and hangs as part of the Loeser collection in the Palazzo Vecchio. (Source)