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 Six Causes

Six types of ground-based light sources were identified that produce enough light to generate a visible reflected image in high-altitude ice clouds.

1. Oil and gas wells and related chemical industry

The majority of the sightings occur when flaring takes place at a petrochemical complex. Flaring is used as a safety measure to release pressure from the pipes or to burn off commercially non-profitable gases. It often accompanies the start-up procedure of a new unit or the closing down of an old one. The main goal of flaring is to convert through oxidation substances in the flare gas stream to their safest form possible. The process is accompanied by a lot of noise, but the most spectacular characteristic are the big flames that escape from the 100 to 200 m high chimneys. Usually, these flames are only a few metres high and are lit for safety purposes alone, but when flaring takes place, the gas flames can blaze up to heights of 60 metres and more. Such enormous flames constitute the brightest, artificial light source on the planet. When a low cloud bank drifts over an industrial site where flaring takes place, the flames are often seen to light up a large part of the sky. On various occasions, this pulsating orange-red glow prompted puzzled citizens to call the fire brigade or local news agencies to report a major fire. Together with big fires, heavily lit fishing boats and human settlements, gas flares rank among the four primary types of lights recorded by the Defense Meteorological Satellite Program during a six month time period in 1994-1995 [13].

petrochemical complex

Flames emanate from the tall chimneys of a petrochemical complex in Antwerp, Belgium.

Often, flaring activities are reserved for holidays and weekends, but not seldom they can last a full week or even longer. In principal, flaring is limited to an absolute minimum because of the dangers involved and the serious pollution it entails. With flaring now being recognized as a large environmental problem, initiatives have been taken to reduce flaring of gas in association with crude oil production. Impressive results have already been achieved in Canada, Norway and the United Kingdom. With flaring reductions on the increase, fewer sightings of atmospheric reflections from gas flares are to be expected. This effect is not noticeable in our case collection because recent observations have found their way more easily to CAELESTIA due to the project's close monitoring of the situation since 1993.

Living only a few kilometres southwest of the petrochemical complex in the port of Antwerp, the author had the opportunity to observe and photograph light pillars produced by flares on various occasions himself.

2. Blast furnaces and steel factories

steel factory chimneys

A giant flame escapes from one of the chimneys of a steel factory near Charleroi, Belgium.
[© Uwe NIGGEMEIER - photo used with permission (more pictures by Uwe NIGGEMEIER can be viewed at]

tiltable Thomas converter

A tiltable Thomas converter at the steelworks in Longwy, France.
[Image scanned from a French school book on geography, published by Librairie Armand Colin in Paris in 1972]

Apart from the very large flames that sometimes escape from the chimneys of steel factories, the glow produced by a blast furnace converter can also cause unusual reflections in the night sky. The light coming from these converters is however different from the light emitted by flames coming from chimneys. In the case of a blast furnace, molten scrap and cast iron is poured into the confined space of a converter. This pear-shaped container has a circular opening on top projecting the glow of the fire onto the clouds much in the way a spotlight does. Because the converter's mouth projects the light more focussed than the flame of a fire-stack, it will produce a rather well-defined circular image on any low cloud with a relatively flat basis. Only the orange-red colour and the proximity of a steel plant make it possible to distinguish such a reflection from that of a spotlight. As with gas flares, it is only when the reflection occurs in high-altitude ice clouds, that the much rarer light pillars do appear.

A particularity of the circular low-cloud reflections caused by blast furnace converters, is that they can move up and down. Although reports of round lights with vertical movements constituted a major riddle when we set out to study unusual atmospheric reflections, the answer eventually proved obvious: most of the converters, that are used to make steel out of raw iron, can be tilted. This makes it possible to fill and empty them quickly and easy. The entire process to burn off all unwanted substances usually takes no longer than 20 minutes. When the glow from the furnace mouth reflects off water-droplets at the basis of a cloud deck, the reflected image will follow the movements of the converter. However, when the glow is reflected in an ice-crystal layer at a much higher altitude, a stationary pillar will appear. As the full converter is turned upward, the pillar will stay in the same place because the location of the light source remains unchanged. Only an increase in brightness may be noticed because more light is projected skywards.

A most unusual situation occurs when both types of reflections happen simultaneously, i.e. when the glow from the furnace mouth projects a round image on a patch of low cloud and at the same time produces a pillar-shaped image in a stratum of ice-crystals at a higher altitude. Such a combination of different types of reflections may result in the unusual sight of a stationary luminous cigar with a luminous disc seeming to emanate from the top or bottom of the cigar. A situation that calls to mind numerous UFO reports of cigar-shaped "mother ships" and their smaller disc-shaped "scout ships".

3. Searchlights and spotlights

Searchlights and spotlights too can produce the two types of reflections mentioned above: the commonly observed round patches of light, caused when the focussed light beams hit the base of a low cloud, and the rarer pillar-shaped reflections in high clouds. As with tiltable blast furnace converters, a combined effect may occur. When several rotating spotlights are mounted on a platform, round luminous discs may be seen darting through the clouds in different directions, while, at the same time, a stationary light pillar may be visible through a gap in the cloud cover [14].

2500 Watt

The beams pictured here emanate from a powerful 2500 Watt discharge lamp called a "booster". The result is an impressive display of multiple rotating, opening and closing light beams rendered visible by layers of haze close to the ground.
[© Novalight - photo used with permission (more photos of boosters and spotlights can be found at, as well as in our own picture gallery under light shows)]

4. Fishing boats

For centuries it was the custom in Asian waters to attach baskets with large fires to the sides of fishing boats. The purpose of these fires was to lure squid up to the surface, so that they could be netted at night. Actually it's the plankton and the fish on which squid prey that come to the sea's surface. The fires are used to imitate daylight, which is when these smaller organisms normally come out of their hiding places.

Because these squid boats not necessarily stay in one place, the reflected images created by the fires can change place as well. These fairy-like displays have led some to attribute the lights to a divine origin [15].

In recent decades squid boats are equipped with bright artificial lights attached to a cross-beam that extends on both sides of the boat. One single boat can carry several hundred thousand watts of incandescent light (mostly mercury vapour lights), bright enough to cause pillar-shaped reflections identical to those caused in earlier years by the fires, but with one difference: the lights are now a whitish blue-grey instead of orange-red [16]. The lights of these modernized squid fleets can be so bright that they are visible in satellite images of the ocean taken from 500 miles above the earth [17].

lights attracts fish to the surface

A small fishing boat near Sai Kaew Beach, Thailand. The lights attract plankton and fish to the surface; squid and other predators follow, and are caught.
[Image found at (author and copyright holder unknown)]


Photo taken near Hakodate, northern Japan, showing the bright lights on squid-fishing boats. [Author unknown - image found on]

Besides in the Sea of Japan, the Pacific Ocean waters north of Japan, the Yellow Sea, the Formosa Straight and the East China Sea, the Defense Meteorological Satellite Program located large numbers of heavily lit fishing boats in other parts of Asia as well. These include the Gulf of Tonkin, the Gulf of Thailand, near-shore waters of the Andaman Sea and many areas in the Philippines. Outside Asia, fishing boats with bright lights are operating in Californian waters and along the continental shelf offshore from Argentina. Short light pillars
Short light pillars caused by a Japanese fishing fleet off the north coast of Japan, photographed from the city of Fukui in Honshu.
[Photo scanned from Spacious Skies, written by Richard SCORER & Arjen VERKAIK, and published David & Charles, London, in 1989 (author and copyright owner unknown)].

5. Fires

Occasionally, prairie fires, forest fires, but also small fires (bonfires and burning haystacks for instance), have generated light pillars in high clouds. Small fires as the cause of aerial reflections are however poorly represented in our collection of cases because the light they produce is often too weak to reach the altitudes at which cirriform clouds form. Burning buildings tend not to generate reflections because most of the time the thick smoke that accompanies such fires shields the flames from the sky.

Unusual light phenomena in a variety of shapes and sizes have been recorded in connection with earthquakes [18]. Anomaly researcher William CORLISS lists the following: flashes of light, lightning, aurora-like streamers and rays, flames issuing from the ground, sky glows and St. Elmo's Fire [19]. Italian researcher Ignazio GALLI mentions several other classes of luminous phenomena seen during seismic activity, some of which closely resemble the reflections that we are interested in, such as: "fire-columns" (colonne di fuoco) and "beams of fire" (trave di fuoco) [20].

Some researchers have argued that earthquake lights are caused by positive charges generated by huge stresses in the Earth's crust. Others are more inclined to attribute the lights to gases and dust that are injected into the atmosphere and alter the air's electrical properties [21]. We wonder if some of the luminous phenomena reported during or immediately after an earthquake, and in particular those phenomena that are described as "columns" or "beams of light", cannot be explained in terms of pillar-shaped reflections from fires caused by the earthquakes in question. It is known that earthquakes not only cause fires indirectly (pipe-line ruptures, falling candles and short circuits setting fire to buildings), but that even the friction caused by land slides can produce enough heat to set fire to trees [22].

6. Volcanoes

Sporadically, beams of light and other luminous phenomena have been reported in connection with volcanic activity. It seems plausible that some of these light beams can be accounted for by the glow from the crater mouth reflecting off high altitude ice-clouds. Likewise, it is conceivable that the streamers of glowing red lava gliding downhill and setting fire to trees, can explain some of the more complex luminous phenomena reported. Although theoretically possible, we were unsuccessful in unearthing good examples of atmospheric reflections caused by volcanic eruptions. A possible explanation is that volcanic regions are too mountainous for flat horizontal ice-crystal layers to form (the unevenness of the landscape causing too many local distortions in the airflow). The upward forces and the heat that accompanies an eruption may also work against the formation and grouping of ice-crystals. On the other hand, light pillars in high clouds can be seen over great distances with reflection often occurring many miles from the light source. Descriptions of vertical shafts of light seen in connection with volcanic eruptions are indeed extremely rare. Only Charles FORT, in his unorthodox book Lo!, cites a few examples but, in spite of our efforts, none of the references FORT mentions could be tracked down [23]. We might also add that most reported volcano lights are short-lived and are believed to be electrical discharges between clouds of electrically charged dust and steam [24].

 Notes & References

[13] ELVIDGE, Christopher D. et al, "Nighttime Lights of the World: 1994-95". This data-set can be downloaded at

[14] See the caption of image number OP-PH-16 in our picture gallery.

[15] KOLOSIMO, Peter, Zij kwamen van andere planeten, Hollandia, Baarn, 1971, p. 100 (original title: Non è terrestre, Sugar Editore, Milan, 1968).

[16] See for example: "Shipping Lights - Tasman Sea" in The Marine Observer, Vol. 59, No. 303, January 1989, pp. 23-24, and "Aurora or squid boat?" in the letters section on pp. 44-45 of the same issue.


[18] HALLET, Marc, Lueurs Géophysiques, Liège, 1994 - The author refers extensively to the works of Robert MALLET, published in various issues of Report of the British Association for the Advancement of Science between 1851 and 1855. Another much-quoted source in HALLET's monography is: MONTANDON Frédéric, Geographica Helvetica, Switzerland, 1948. See also our short article on earthlights elsewhere on the "research and discussion" page.

[19] CORLISS, William R., Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena, The Sourcebook Project, Glen Arm, 1982, p. 110.

[20] TERADA, Torahiko, "On Luminous Phenomena Accompanying Earthquakes" in Bulletin of the Earthquake Research Institute, Tokio Imperial University, 1931, p. 227.

[21] See for instance:

- DERR, John S., "Luminous Phenomena and Seismic Energy in the Central United States" in Journal of Scientific Exploration, Vol. 4, No. 1, 1990, pp. 55-69.

- DEVEREUX, Paul, Earth Lights, Turnstone Press, Wellingborough, 1982.

- DEVEREUX, Paul, Earth Lights Revelation, Blandford Press, London, 1989.

- DEVEREUX, Paul, McCARTNEY & Paul, ROBINS, Don, "Bringing UFOs down to Earth" in New Scientist, 1 September 1983, pp. 627-630.

- FINKELSTEIN, David & POWELL, James: "Earthquake Lightning" in Nature, 21 November 1970.

- LOCKNER, D.A., JOHNSTON, M.J.S. & BYERLEE, J.D.: "A mechanism to explain the generation of earthquake lights" in Nature, 3 March 1983, pp. 28-33.

- PERSINGER, Michael A. & LAFRENIERE, Gyslaine F., Space-Time Transients and Unusual Events, Nelson-Hall, 1977.

- PERSINGER, Michael A., "The Tectonic Strain Theory as an Explanation for UFO Phenomena: A Non-Technical Review of the Research, 1970-1990" in Journal of UFO Studies, New Series, Vol. 2, 1990.

- WAGNER, William: "Earthquake Lights in Alaska: A Summary of the Evidence" in Mines & Geology Bulletin, June 1978 (Vol. XXVII, No. 2), pp. 6-8.

The latter article mentions a "false sunrise" over the western side of Cook Inlet, Alaska. Residents of Homer described it as yellow-to-orange sheet lightning. Although used in earthlight studies, there is no indication that these lights were in any way linked to seismic activity. The obvious explanation, which was also advanced at the time, is that the lights were caused by offshore oil-rig gas flaring reflecting off cloud cover.

[22] LANE, Frank W., Les colères de la Nature, Hachette, Paris, 1949, page unknown. Thanks to Marc HALLET for sending us photocopies from this work.

[23] FORT, Charles, Lo!, Ace Books, Inc, New York, 1941, pp. 258-259.

[24] CORLISS, William R., Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena, The Sourcebook Project, Glen Arm, 1982, p. 115.