What happened
Isolated reports of strange lights in Hessdalen go back at least to the 1930s, but the real wave began in December 1981. Until mid-1984, residents saw them as often as 15–20 times a week: white, yellow, or red balls hovered over the valley for anything from a few seconds to more than an hour, sometimes motionless, sometimes moving at tremendous speed. Tourists and journalists began flocking to the small village. In 1983 Project Hessdalen was launched, initiated by Norwegian and Swedish UFO associations, and scientists joined the field measurements with radar, a spectrometer, and a magnetometer. In 1998 an automated measuring station was set up in the valley, and it continues to record the phenomenon to this day. Sightings are now far less frequent – a dozen or so a year – but the valley remains a natural laboratory for physicists from Norway and Italy.
Witnesses
Residents of the valley, tourists, and Project Hessdalen participants; the phenomenon is recorded by the cameras, radar, and spectrometers of the automated measuring station.
Explanations and hypotheses
There is no definitive explanation, but the hypotheses are becoming increasingly specific. Spectral analyses have pointed to oxygen, nitrogen, and titanium, among other elements, suggesting the combustion or ionization of dust from the valley’s mineral-rich rocks. Other researchers propose a dusty plasma produced by the decay of radon, or electrical phenomena in rocks that may act as a natural battery. Some sightings turned out to be aircraft, cars, and stars – but not all of them.
Unexplained There is no convincing explanation.
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