Case file No. 16 · Fields, photos and lights
The Hessdalen lights
The claim
Mysterious lights appear in the Hessdalen valley in Norway. They are alien craft, or an unexplained natural phenomenon.
Open
The lights are real and unexplained. They are not shown to be craft.
The lights have been recorded and measured over many years, including by cameras and spectrographs. Researchers agree that something real occurs, but no explanation has been confirmed. No data show a craft or a machine.
Short answer
Since the early 1980s residents of the Hessdalen valley in central Norway have reported lights, often seen at night, hovering, moving or pulsing for minutes or hours [1]. In early 1984 the project ran a field campaign with cameras and radar and recorded the lights [1]. Later work, including Italian and Norwegian teams, used spectrographs and an automatic measurement station [2][4]. Their results show that some light sources are real and bright, and some sightings are explained as cars, aircraft or stars [2]. A proposed explanation involves dust and plasma, but it is a hypothesis [3]. Whether a single explanation covers all sightings remains unsettled [2][3].
What supporters can show
Scientists have studied it for decades
A natural explanation has been proposed
Some lights have no ordinary source
Claims that supporters often repeat and that we looked for but could not confirm in a reliable source.
- Lights that respond to signals. Reports that the lights react to flashlights or lasers. We found no controlled measurement.
- Intelligent control. Claims that the lights act as if controlled. We found no data that supports this.
What science found
Many sightings have ordinary sources
Researchers working in the valley say that part of the sightings are car headlights on distant roads, aircraft, and bright stars or planets seen through haze [2]. Their reports separate these from the events that remain unidentified.
The measurements point to natural physics
Measurements of the lights with spectrographs and cameras have been discussed in terms of light emission from heated or ionised matter [2][3], not machines. The data show nothing like an engine, a structure or a signal.
The valley has features that can produce unusual effects
The valley has deposits of minerals including iron, zinc and other metals and a lake and a river, and a sparse population. Proposed explanations, such as the dusty-plasma model, relate to the particles and gases in this environment [3].
Rare sightings do not show a craft
No sighting has produced a solid object, a recovered part or a controlled demonstration. A natural phenomenon that is rare and not yet understood is the simplest reading [2].
What is still open
What produces the Hessdalen lights is unknown. It is one of the few cases where instruments and a permanent station exist, so data collection continues [2][4].
If this happens to you
If you go to see them, be aware that most nights show nothing, and that many lights are cars. Check the research station's information before travelling [4].
Sources
- Strand, E. P. Project Hessdalen 1984: Final Technical Report. Project Hessdalen. Source
- Teodorani, M. (2004). A long-term scientific survey of the Hessdalen phenomenon. Journal of Scientific Exploration, 18(2), 217–251.
- Paiva, G. S., & Taft, C. A. (2010). A hypothetical dusty plasma mechanism of Hessdalen lights. Journal of Atmospheric and Solar-Terrestrial Physics, 72(16), 1200–1203.
- Hessdalen automatic measurement station (AMS). Østfold University College, Norway. Source
Change log
15 November 2026: First publication. Verdict: Open.