“The light is being carried hundreds of kilometres by this layer of air that traps the light and stops it from being dispersed.” “It’s like the way light travels in a fibre optic, no matter which way you bend the fibre,” he said. A certain shape of temperature inversion will mean that light near the ground will be refracted in such a way that it travels in a curved path around the globe. Such mirages are caused by a temperature inversion, where cold dense air is trapped next to the ground under a layer of warmer air. Pettigrew - who been reading about the Fata Morgana in which landforms that are beyond the horizon appear to float above it in an inverted form - thought this might help explain the Min Min lights. Refraction of a distant light source around the globe (Pic: Clinical and Experimental Optometry) They later found out there had been a car driving straight towards them at the time they had seen the light. “We calculated it was over 300 km away which was over the horizon,” Pettigrew said. Pettigrew and his two companions drove across the plains and used a car compass to work out how far away the light was, but had to drive five kilometres before there was any change in the direction of the compass. “We had a big argument – no one could agree what it was and how far away it was.” However when they stopped and turned out the headlights, it was still there, bobbing around as if it had a life of its own. On a later occasion while driving with colleagues, the three saw what they thought was the eyeshine of a cat about 50 metres in front of their vehicle. It went down to the horizon and then sat on the horizon for some time.” When Pettigrew first encountered the Min Min he thought it was the planet Venus: “But it didn’t set. “Just imagine you were sitting in your living room and a light appeared hovering in the middle of the room and as you moved your head to try and see the cause of the light, the light moved with you.” 'It’s a bit embarrassing for them because hardened outback men can be brought to tears by this thing. 'I talked to old timers out there who had seen it and they were terrified by it,' he told ABC Science Online. Pettigrew studied the phenomenon in the Channel Country, Western Queensland, where he said it has been disturbing the locals for many years.

The work was published in the current issue of Clinical and Experimental Optometry. Professor Jack Pettigrew, of the University of Queensland in Brisbane claims the lights are actually an inverted mirage of light sources which are, in some cases, hundreds of kilometres away over the horizon. An Australian neuroscientist claims he can conjure up the mysterious Australian outback phenomenon of the Min Min lights, now that he has worked out what causes them.

Fata morgana phenomenon