An Australian man believes he spotted an extraterrestrial visitor on Saturday, when a UFO emerged in the sky above the Northern Territory.

Alan Ferguson captured the close encounter on camera on Saturday morning, when an alien spaceship soared above his Acacia Hills property about 50km south of Darwin.

The UFO expert, who documents sightings from around Australia on his website UFOTerritory, said he set his camera on a fast-speed loop.

To read more and view the video, click here.