If you ever visit Eastern Australia, there's a rare chance you may encounter the Min Min light, a spectral luminescence that trails the viewer and is often mistaken for a UFO. But what causes this bizarre flickering pursuer?
As evinced by recent news reports, Min Min lights still bedevil motorists and are a fixture of Australia's paranormal culture. The town of Boulia has a particular affinity for the lights, which have been documented prior to European settlement of Australia.
Also — like any weird phenomenon worth its salt — Min Min lights have been the subject of overblown dramatization à la Unsolved Mysteries.
The Min Min light occurs when light, from a natural or man-made source, is refracted to an observer who is tens, or even hundreds, of kilometres away, by an inverted mirage, or Fata Morgana [...] Named after the Morgan fairy, who was reputed to be able to conjure cities on the surface of the sea ice, the Fata Morgana has a real physical phenomenon, being caused by a temperature inversion [...]
A cold, dense layer of air next to the ground (or sea, or sea ice) carries light far over the horizon to a distant observer without the usual dissipation and radiation, to produce a vivid mirage that baffles and enchants because of its unfamiliar optical properties.
You can read Pettigrew's full paper on Min Min lights here. As an addendum, he insists that understanding the origin of the phenomenon does not detract of the wonder of the Min Min light but rather makes them all the more awe-worthy:
I know that there will be great resistance to the acceptance of this and any other explanation of the Min Min light from many in the Outback who are cynical about attempts by city slickers to reduce the magic and wonder of the phenomenon. I have some sympathy with this reaction but would plead that my approach to putting the phenomenon on a more understandable basis does not necessarily explain it away but rather may enhance one's experience of it.