Sighting of a UFO is first mentioned in Occult Fan IV, a magazine that centers on bizarre and mysterious events happening around the world. The magazine hints on the sidequest involving encounters of the third kind.
To encounter the UFO, the player must visit four locations. A fixed battle will ensue (even with No Encounters equipped) and the UFO will appear. Once it has appeared, it will not show up a second time in the same location. The locations can be visited in any order.
Winhill Bluffs: The UFO is sighted on the bluffs around Winhill. The UFO abducts a cow.
Kashkabald Desert: Kashkabald Desert is in southern Esthar near Cactuar Island, and the UFO is sighted on the western part of the desert, carrying a pyramid.
Heath Peninsula: Heath Peninsula is in eastern Trabia, and the UFO is sighted on the small gray island east of the peninsula carrying a crop circle.
After the fourth sighting, the player must fly the Ragnarok to Grandidi Forest in northern Esthar and land on the highlands above the Chocobo Sanctuary, and they will have a up-close encounter with the UFO.