According to Project Hessdalen (1), being conducted by Osfold University College, the phenomenon consists of mysterious lights spotted up and down the length of the valley, often alarming people who observe them.
Even though some reports exist as early as 80 years ago, the frequency of the lights spiked between 1981 and 1984.
At its peak, 20 reports a week of strange lights in the region were occurring. The frequency has tapered off, though the occasional sighting still occurs. Project Hessdalen has maintained an automatic observation post in the valley since August 1998.
A 1985 study of the lights, which employed a number of scientific instruments, came to decidedly inconclusive findings.
What Is the Phenomenon?
“What is this phenomenon? What do we know about it?
“We have not found out what this phenomenon is. That could hardly be expected either. But we know that the phenomenon, whatever it is, can be measured.
“Beside the light measurements, it can be ‘measured’ by radar and laser. Perhaps the measurements we did on the magnetograph and spectrum analyser are due to this phenomenon as well. We have to do more measurements with these instruments, before we can be sure of that.
“We got no measurements with the Geiger counter, seismograph or IR-viewer. But I will prefer to bring these instruments as well in the next period. And it might be useful to also record events that seem to be unimportant. We stand in front of something unknown, and we must collect everything that might lead us to an answer on what this is.
“Some hypotheses of what this phenomenon is, might be weakened or strengthened after analysing the measurements in this report. However, the different hypotheses will not be discussed here. The report is more intended to set a basis for further discussion on what it can be, and what should be used in the nest period” (1).
Besides the usual theories about aliens (2) and ghosts, scientific explanations for the lights abound, ranging from plasma to ball lighting. The UK Daily Mail (3) related a theory offered by an Italian scientist named Jader Monari of the Institute of Radio Astronomy in Medicina, Italy, who suggested that the valley is one, huge natural battery.
Could There Be a Natural Cause?
Monari and a team of researchers found that one side of the valley was rich in iron and zinc and the other side in copper. The theory is that electricity flows between the two sides of the valley through sulphur in the river between the two. Occasionally bubbles of ionized gas are created, causing the lights. The lights are moved about by natural electromagnetic field lines.
Another, similar idea, offered by Bjorn Gitle Hauge, an electrical engineer at Ostfold University, involves the idea that geography, geology, and climate generate a charge from static electricity, causing the lights to occur.
In either case, scientists believe that the phenomenon may point the way toward a new method of storing energy, a developing technology that supports renewable energy, such as solar or wind.
One of the more recent sightings of a Hessdalen Light was reported by a site called Texas UFO Sightings (4). A video of the occurrence shows flashes of light occurring in the right hand side of the video.
After a few minutes, the flashes stop. Then a glowing orb appears in the night sky moving rapidly and steadily from left to right.
Whether the phenomenon is caused by aliens, as some suggest, or has a more natural cause, as most scientists believe, the show must be something impressive to watch in person.