Published: 12:48 AM 5/28/2014
by M. Michael Brady
The hovering balls of light that have been seen above Norway’s Hessdalen (“Hess Valley”) just north of Røros in Sør-Trøndelag County have long defied scientific explanation. But the curiosity of Norwegian scientists following spectacular displays of the lights in the early 1980s has triggered research into what now is called the Hessdalen phenomenon. An explanation of it may now be at hand.
The Hessdalen phenomenon sorts into the broad class of apparitions known as atmospheric ghost lights. The class most famously includes will-o’-the-wisp, also known as ignis fatuus (Medieval Latin for “foolish fire”), well ensconced in English as well as European folklore.
The connection with folklore long deterred scientific inquiry.
Moreover, the United States Air Force had extensively studied anomalies in the sky in the early 1950s that could not be attributed to known objects or phenomenon, grouping them under the designation unidentified flying objects (UFOs). The studies ended in 1953 with the conclusion that UFOs were not worthy of scientific pursuit. So though UFOs remained popular in fiction, mainstream science lost interest in them.
Three decades later, scientists at the Østfold University College at Halden who were curious about the Hessdalen phenomenon came together with equally curious colleagues from Sweden in early June 1983 to discuss how it might be researched. They bravely bucked the lack of scientific interest in UFOs and started Project Hessdalen.
Slowly but surely the Project gained recognition. The “First International Workshop on the Unidentified Atmospheric Light phenomena in Hessdalen” was held in March 1994, drawing 27 research scientists from eight countries. One of the conclusions of the workshop was that the Hessdalen phenomena were not forms of ball lighting, which had been one of the earlier explanations of them.
Clearly, more data were required. An automatic monitoring station was set up in 1998 to photograph the phenomena whenever they occurred, not just when they were seen by people. By 1999, the research became an international undertaking in Project EMBLA, a Norwegian-Italian programme together with the Instituto di Radioastronomia (IRA) of the Italian National Research Council (CNR).
EMBLA soon produced scientific results, and The Society for Scientific Exploration, an international organisation of scientists and scholars devoted to the study of unusual and unexplained phenomena, published a benchmark scientific study of the Hessdalen phenomenon in 2004 (Further reading).
Much has been revealed about the phenomenon to date. Most significantly, scientific measurements suggest that it is some sort of plasma (see “About plasmas” below). If so, the contribution to scientific understanding is far reaching, as plasmas may account for all the observed aspects of UFOs.
The big question, then, is what causes the plasmas. Radioactive decay, as of radon in the atmosphere, can trigger plasma. So one theory holds that radioactivity causes the Hessdalen phenomenon. But the background radioactivity in the valley is lower than in its surroundings. Yet that doesn’t completely rule out a radioactive trigger of the plasmas, because bubbles of radon might come up from the water filling nearby abandoned mines.
Another theory holds that the unusual geology of the valley has made it a giant natural battery. Rocks rich in iron and zinc form the anode on one side of the Hesja River in the floor of the valley. On the other side of the river, rocks rich in copper form the cathode. Sulphur from the mine leaches into the river, forming a weak acid, making it an electrolyte between the anode and cathode.
But the natural battery theory has a weakness in that the electric field provided by it seems insufficient to explain the charge that might initiate plasma. That said, the Hessdalen phenomenon seems particularly prominent during displays of the Aurora Borealis, which plausibly could provide the ionization necessary for initiating plasma.
Today, the solution of the mystery of the atmospheric lights of Hessdalen seems within reach. Research has been stepped up, and the system for monitoring the valley will be expanded this summer. Whether the results will reveal new scientific insights or just explain an odd phenomenon remains to be seen.
- Plasma is one of the four fundamental states of matter, along with solid, liquid and gas. A plasma is formed whenever a gas, as in the air, is ionised so that its constituent atoms or molecules gain or loose electrons.
- Plasmas give off light, sometimes visible and sometimes not, as infrared or ultraviolet light, are electrically conductive, and may be caused by heating or by passing electricity through a gas.
- Everyday examples of plasma include lightning and neon lights, which might be called “plasma lights” because the light they emit comes from plasma inside their glass tubes.
- Plasma is the most abundant form of matter in the universe, because our Sun and most stars are spheres of plasma.