The Hessdalen lights: a valley that glows

Hessdalen is a narrow valley in central Norway. The photographs in this file show it in the winter of 1953: snowed-in farms, a farmer hauling moss by horse sledge. They come from the National Archives of Norway, and they show the valley decades before anything happened there. They are not pictures of the lights. I want that clear before anything else, because there is, as yet, no free and verified photograph of the phenomenon that this archive can show you.

Then, from late 1981, residents of the valley began reporting frequent lights[hessdalen-org].

Scene · reconstructed from the paperworkPicture it. The file's sources describe lights over the hillsides and the valley floor, some of them hovering for long periods (the record[hessdalen-reports]). The file doesn't say who saw the first one, or on which night, and I won't name a witness the papers don't. What it says is that the reports came often, and kept coming.

How often? The 1984 field report[hp-report-1984] gives a figure that has stayed with me. At their peak, sightings ran at close to twenty a week. Later, they settled at something like twenty a year. For a valley of a few farms, that is not one strange evening. It is a season, and then a habit.

There is a film in this file, Sky of Hessdalen[sky-of-hessdalen-yt], in which people from the valley describe in their own words what they have seen; nineteen witness descriptions, with English subtitles. It is a witness record, not a measurement. It carries the weight of people who live under that sky, and the file weights it accordingly. There is also a Norwegian site devoted to the phenomenon[hessdalsfenomenet], whose owner and standing we have not yet verified.

So the opening scene is a valley, not a night:

• a quiet place, photographed in 1953, long before the lights (the record[hessdalen-org]);
• reports of lights from late 1981 (the record[hessdalen-org]);
• some lights hovering for long periods (the record[hessdalen-reports]);
• a peak near twenty sightings a week (the record[hp-report-1984]).

What makes Hessdalen different from most cases in this wing is what happened next. People did not only tell each other what they had seen. Someone came to measure it, and the measuring has never really stopped.

That is a rare thing in a file about lights in the sky, and it is where the paper trail begins.

In most light cases the paper trail is a stack of witness statements. In Hessdalen it is a stack of field reports and data, which is why this file carries the grade recorded.

1983: Project Hessdalen. A research effort called Project Hessdalen[hessdalen-reports] began instrumented field work in the valley. The idea, for this kind of subject, was unusual: instead of collecting stories, collect measurements. The project's own site[hessdalen-org] describes it as having studied and instrumented the lights since 1983. Among the people the file's notes list at its core is Erling Strand, the project lead (the record[hessdalen-reports]).

1984: the first field campaign. The 1984 field report[hp-report-1984], by Strand and the project, covers a campaign from 21 January to 26 February 1984. Over those five weeks it logged 188 reports, 53 of them from Hessdalen itself. I like that the report keeps the two numbers apart. It is a small act of honesty: not every report from the region is a report from the valley.

1998: the automatic station. From August 1998 an automatic measuring station[hessdalen-reports] has recorded in the valley. The file's margin note says it plainly: the valley has been watched by machines since then, on nights when nobody is standing on the hillside.

2004: the long-term survey. The physicist Massimo Teodorani published A Long-Term Scientific Survey of the Hessdalen Phenomenon[teodorani-2004] in the Journal of Scientific Exploration, describing instrumented work from the Italian side. The exact host of the PDF is still on our list to verify.

2010: a mechanism proposed. G. S. Paiva and C. A. Taft proposed a dusty-plasma mechanism[paiva-taft-2010] in the Journal of Atmospheric and Solar-Terrestrial Physics. It is peer-reviewed, and it is a hypothesis, not a confirmed mechanism. The file is careful to say so, and so am I.

The project keeps an index of its reports[hessdalen-reports]; historic ones are also held on its older site.

So the trail, in order:

• 1981: reports begin (the record[hessdalen-org]);
• 1983: instrumented work begins (the record[hessdalen-reports]);
• 1984: the first field campaign, 188 reports (the record[hp-report-1984]);
• 1998: the automatic station (the record[hessdalen-reports]);
• 2004 and 2010: survey and theory (Teodorani[teodorani-2004], Paiva and Taft[paiva-taft-2010]).

What all of it adds up to is the line the dossier's analysis opens with: what is documented is repeated instrumented recording (the record[hessdalen-reports]). What is not documented is a mechanism. That gap is the turn.

So what are they? Here is the turn, and it is not the one some people hope for.

The honest answer starts with the ordinary. According to the project's own reports[hessdalen-reports], many sightings in the valley have turned out to be car headlights, aircraft or stars. Once those are removed, only a minority of reports may belong to the unexplained phenomenon. That is the file's other side, and any fair account has to begin there rather than end there. The 1984 report's[hp-report-1984] habit of separating valley reports from regional ones belongs to the same discipline.

For the remaining core, scientists have proposed natural explanations. The dossier lists three families (the record[hessdalen-reports]):

• Burning dust in the air.
• Plasma, a glowing, electrically charged gas.
• Piezoelectric effects, where stressed rock produces electric charge.

A refinement of the plasma idea appears in the 2010 paper by Paiva and Taft[paiva-taft-2010]: a dusty plasma, as a hypothetical mechanism. Teodorani's survey[teodorani-2004] brought further instruments to the question.

Each idea has supporters. None is accepted (the record[hessdalen-reports]). And every one of them runs into the question this file lists as its first open question: what is the energy source of the lights? Something has to keep a ball of light glowing, sometimes for long periods, in open air (the record[hessdalen-reports]).

Here is where the turn bends away from the legend. In many light cases the official story tilts towards nothing was there. In Hessdalen it tilts the other way, but not in the direction of visitors. The lights are real enough to be recorded by cameras and instruments (the record[hessdalen-reports]). That much is settled. What the record does not show is a craft, or an intelligence, or any intention behind them. Nothing in the data requires visitors, and the file does not claim any.

So the Finding stays where the dossier put it: unexplained. Not mysterious in the sense of supernatural, and not explained either. A natural phenomenon, probably, without an accepted mechanism (the record[paiva-taft-2010]). I find that one of the more satisfying states a file can be in. It means people measured before they speculated.

What it also means is that the work is not finished, and the valley is still being watched.

This file's status is open, because new material is still coming. The automatic station[hessdalen-reports] has been recording since August 1998, and as far as this file knows it has not stopped.

Here is what the documents do not settle:

• The energy source. What keeps the lights glowing, sometimes for long periods, is the question none of the theories has answered[hessdalen-reports] to general acceptance.
• The mechanism. Burning dust, plasma, piezoelectric effects and a dusty plasma[paiva-taft-2010] have all been proposed. None is accepted.
• The true core. Given that many sightings are headlights, aircraft or stars[hessdalen-reports], how large is the unexplained remainder? The 1984 campaign[hp-report-1984] logged 188 reports across five weeks; the file does not give a figure for how many survived explanation.
• The frequency drop. Sightings fell from close to twenty a week at their peak to about twenty a year (the record[hp-report-1984]). The file does not say why.
• The image. There is still no free, verified photograph of the lights for this archive to show. The valley photos are from 1953 and are context only.
• Some of our own references. The host of Teodorani's PDF[teodorani-2004], the exact title of the Paiva and Taft paper[paiva-taft-2010], and the standing of the Norwegian phenomenon site[hessdalsfenomenet] are still on our list to verify.

And here is what is not open. The lights are real enough to be recorded by instruments (the record[hessdalen-reports]). They do not, on the evidence in this file, show a craft or an intelligence. Both statements are part of the Finding, and I won't let either one carry the other away.

I keep coming back to the witnesses in Sky of Hessdalen[sky-of-hessdalen-yt], describing in plain words a thing the instruments have also seen. It is unusual for those two kinds of record to agree. Usually one of them is missing.

What powers the lights of Hessdalen? After four decades of watching, the valley is measured and recorded (the record[hessdalen-reports]). It is still not explained.

The field reports, the survey, the theory and the timeline are below. Start with the 1984 report; it is the closest thing this file has to a first night.