Since the 1930s, residents and visitors of the Norwegian Hessdalen Valley have reported strange glowing balls in the sky. These unexplained lights for many years, day and night, were recorded by many photographs.
According to computer scientist Erling Strand, the lights suddenly stopped in 1983 and reappeared in 1984. Strand and his team used radar, a magnetometer, a radio spectrum analyzer, a seismograph, cameras, a Geiger counter and an infrared camera to assess the phenomenon.
According to the collected data, as well as eyewitness reports, the lights can move slowly, and sometimes rush and follow a random path, and can last from a few seconds to more than an hour. The size of the lights had the size of a car.
What causes them? Unfortunately, we don’t know for sure, but there are a number of interesting theories.
One theory put forward by researchers in 2010 suggests that this phenomenon is caused by the decay of radon in the atmosphere, given that the Hessdalen Valley (and Norway as a whole) has one of the highest concentrations of radon in Europe.
There is an even more interesting idea, first proposed in 2006. It lies in the fact that this phenomenon can be caused by the fact that the landscape acts as a natural battery, which is then regularly discharged.
The Hessdalen valley is divided into two parts by the river, with zinc and iron-rich rocks on one side of the river and copper-rich rocks on the other. The anode of this “ideal natural battery” will be a section of zinc and iron, and the copper half will be the cathode.
The only thing missing is an electrolyte solution to transfer charge between the two sections of the battery.
The team noted that anomalies in the magnetic field were detected in the area, indicating a natural battery. It is unknown how this battery will produce enough charge to create such visible light, however, the team suggests that the local features of the valley lead to the formation of cold plasma and/or ion bubbles.
Despite all these theories, scientists still have no answer to the question of what causes these mysterious lights.