Hessdalen light

The Hessdalen Light is unexplained light usually seen in the Hessdalen valley in the municipality of Holtålen in Sør-Trøndelag county, Norway.

History and description

Unusual lights have been reported here since 1940s or earlier. Especially high activity of Hessdalen lights took place from December 1981 until the summer of 1984 when lights were observed 15 to 20 times per week. The frequency of the lights caused a gathering of numerous tourists staying there overnight to see the phenomenon. Since then, the activity has decreased and now the lights are observed some 10 - 20 times per year.

The Hessdalen light most often is a bright, white or yellow light of unknown origin standing or floating above the ground level. Sometimes the light can be seen for more than one hour. There are several other types of unexplained lights observed in the Hessdalen valley.

Research

Since 1983 there has been ongoing scientific research often nicknamed "Project Hessdalen", initiated by Dr. Erling Strand. In 1998, the Hessdalen AMS automated scientific research station was built in the valley. It registers and records the appearance of lights.

Later, the EMBLA program was initiated. It brings together established scientists and students into researching these lights. Leading research institutions are Østfold University College (Norway) and the Italian National Research Council.

Possible explanations

In spite of on-going research there is no convincing explanation to the origin of these lights. However, there are numerous working hypotheses.

• One explanation attributes the phenomenon to an incompletely understood combustion process in the air involving clouds of dust from the valley floor containing scandium. Some sightings though, have been identified as misperceptions of astronomical bodies, aircraft, car headlights, and mirages.

• One recent hypothesis suggests that the lights are formed by a cluster of macroscopic Coulomb crystals in a plasma produced by the ionization of air and dust by Alpha particles during radon decay in the dusty atmosphere. Several physical properties (oscillation, geometric structure, and light spectrum) observed in Hessdalen lights phenomenon can be explained through the dust plasma model. Radon decay produces alpha particles (responsible by helium emissions in HL spectrum) and radioactive elements such as polonium. In 2004, Teodorani showed an occurrence where a higher level of radioactivity on rocks was detected near the area where a large light ball was reported. In fact, when radon is released into air, its solid decay products readily attach to airborne dust. A new computer simulation shows that dust immersed in ionized gas (i.e., dusty plasmas) can organize itself into double helixes. The simulations suggested that under conditions commonly found in space, the dust particles first form a cylindrical structure that sometimes evolved into helical structures. Along some spirals, the radius of the helix was seen to change abruptly from one value to another and then back again, providing a mechanism for storing information in terms of the length and radius of a section of a spiral. Hessdalen Lights may take the helical structure. Surprisingly, dusty plasmas may also assume this structure.
• Another hypothesis explains HL as a product of piezoelectricity generated under specific rock strains (Takaki and Ikeya, 1998) because many crystal rocks include quartz grains which produce an intense charge density. In a recent paper, based in the dusty plasma theory of HL (Paiva and Taft, 2010), it is suggested that piezoelectricity of quartz cannot explain a peculiar property assumed by the HL phenomenon – the presence of geometrical structures in its center.

See also

• Ball lightning
• Hessdalen AMS
• Paulding Light
• Will-o'-the-wisp

External links

• Homepage of Project Hessdalen
• Homepage of the Italian Committee for Project Hessdalen
• Hessdalen 2003: luci misteriose in Norvegia by Massimiliano Di Giuseppe (Italian)
• Hessdalen 1998: Triangle Project
• http://adsabs.harvard.edu/abs/2002ph...rept.....T
• http://www.nrk.no/nyheter/innenriks/1.2970467