Categories: FAQs

What are the Possible Explanations for UFO Sightings?

Ever heard of the Hessdalen lights? These bizarre light phenomena have been seen in the Hessdalen valley in Norway at least since the 1940’s, with countless images of up to 30 metre long balls of light captured on camera and video. Appearing as a white or yellow light either floating or zooming around the sky, sometimes for hours, their sightings have been so prolific that scientists from all over the world have traveled to study them in their surroundings and the Hessdalen Automatic Measurement Station (Hessdalen AMS) was even set up specifically to record the phenomenons strange activities.

So far no convincing explanation as to these “phantom lights” have been found, although numerous hypotheses exist as to their origin, including clouds of dust containing scandium from the valley floor combusting in the air; a result of cold plasma arranged as cluster of Coulomb crystals during radon decay; a result of piezoelectricity generated under certain rock strains; or even rocks either side of the valley’s sulphurous river creating a natural ‘valley-battery’ with the ionized gas then charged by solar wind.

Of course, the Hessdalen lights have also attracted the attention of ufologists, as these light phenomena often appear solid, shiny and cylindrical in shape, can hover or shoot off at incredible speeds, and often leave traces of radiation behind. Nowadays, however, few people believe the Hessdalen lights are a result of UFO activity by extraterrestrial visitors.

Nevertheless, the phenomena does raise the question how many apparent UFO sighting in the past have been a result of similar puzzling natural phenomenon like the one regularly observed in the valley of Hessdalen. In fact, the British Ministry Of Defence made its UFO files public in 2006, and in addition to aircraft, weather balloons and Chinese lanterns, one interesting conclusion reached from the MOD’s scientific studies was the following:

“Considerable evidence exists to support the thesis that the events are almost certainly attributable to physical, electrical and magnetic phenomena in the atmosphere, mesosphere and ionosphere. They appear to originate due to more than one set of weather and electrically-charged conditions and are observed so infrequently as to make them unique to the majority of observers. There seems to be a strong possibility that at least some of the events may be triggered by meteor re-entry, the meteors neither burning up completely nor impacting as meteorites, but forming buoyant plasmas. The conditions and method of formation of the electrically-charged plasmas and the scientific rationale for sustaining them for significant periods is incomplete or not fully understood.”

As well as electrical “plasma” phenomena, curiosities such as ball lighting, sprite lightning, lenticular clouds (photo), and astronomical objects such as meteors and comets, a good many UFO sightings are also likely a result of optical phenomenon, particularly the celebrated and complex form of mirage known as a Fata Morgana.

Fata Morgana

A Fata Morgana is an optical illusion created when a layer of warm air resting above cold air forms a refracting lens which distorts light from a distant object making it appear upside down or right side up, magnified, distorted and capable of changing in form rapidly. This mirage is named after the Arthurian shape-shifting sorceress Morgan le Fay, and can be seen on land, as well as at sea where distant object, such as boats, islands, and the coastline have mistakenly been identified by sailors as ghosts ships (Flying Dutchmen), or tricked them into thinking land was closer than was actually the case.

The image of an object located below the horizon can also be refracted vertically above the horizon so that it looks like it is hovering in the sky, while astronomical objects such as the planet Venus when captured by a Fata Morgana can behave remarkably similar to a UFO, darting around the sky and covering great distances, before then vanishing in the blink of an eye. Undoubtedly many UFOs sightings are due to Fata Morgana mirages, such as the Marfa Lights in the USA or the Min Min lights of Australia. Australian neuroscientist Professor Jack Pettigrew from the University of Queensland has studied the Min Min lights, which are ghostly lights which can suddenly appear in front of startled observers and are now believed to be the result of refracted light traveling in a path following the earth’s curvature. As Pettigrew explains:

“It’s like the way light travels in a fibre optic, no matter which way you bend the fibre. The light is being carried hundreds of kilometres by this layer of air that traps the light and stops it from being dispersed.”


While it is exciting to contemplate unsolved mysteries and extraterrestrial encounters, many of the phenomena discussed likely account for a great deal of historical legends and UFO sightings which continue to be regularly reported by people on a daily basis. Now that you are more acquainted with such seemingly supernatural or alien phenomena, next time the conditions are right take some time to look closely for such extraordinary mirages and perhaps you will get a better feel for the stuff that legends are made of.

Peter Christoforou :