The Marfa lights

Donald Witt, a physicist at Sul Ross State University, traced lights to a ranch and to US 67 in the early 1970s; a larger effort he coordinated in March 1975 found nothing but ranch lights and headlights passing behind obstructions on US 67⁠[10]⁠[7]. In March 1994 Paul Devereux and Hal Puthoff found that mirages lift lights from beyond the horizon, that headlights 30 miles or more away on the Marfa–Presidio road can look anomalous, and that vehicles on ranch tracks across Mitchell Flat look like lights skimming the ground; Devereux still judged from witnesses that genuine lights probably appeared now and then⁠[7].

About a dozen members of the UT Dallas Society of Physics Students spent 10 to 14 May 2004 at the viewing area with two video cameras, a traffic counter on US 67 and a chase car in radio contact⁠[2]. Played at high speed, the video showed the lights moving from left to right along one path; their numbers fell as traffic on US 67 fell after dusk; and the chase car's flashing headlights appeared in the same place as the lights, of similar brightness and colour. A light seen passing the chase car's position matched another car passing it. The group attributed every light it observed to headlights on US 67 between Marfa and Presidio⁠[2].

James Bunnell, a retired aerospace engineer, began studying the lights in 2001 and from 2003 ran unattended low-light cameras on Mitchell Flat, later three stations with nine cameras⁠[8]⁠[6]. On the night of 2–3 June 2005, during intense thunderstorms, two stations photographed an extremely bright object that shone for over three hours. Strokes in the National Lightning Detection Network match its origin in time and place; triangulation put it on the ground about 28 km from the farther station, and its peak output was about 10 kW of visible light⁠[8]. The same camera system recorded the first gigantic jet seen over continental North America, on 13 May 2005⁠[11].

In May and June 2008 a Texas State University team watched for 20 nights with a Schmidt-Cassegrain telescope, a CCD spectrometer, logged bearings and video. It identified streetlamps, headlamps and fires, saw nothing that met the criteria for a genuine Marfa light, and showed that the absorption of atmospheric oxygen gives the distance of a continuum source to 6% or better beyond 4 km⁠[5]⁠[12]⁠[13]. The team noted that such lights had appeared on only about 0.9% of the nights Bunnell's cameras monitored between November 2000 and May 2008⁠[7].

In 2020 Manuel Borraz Aymerich and Vicente-Juan Ballester Olmos re-examined 17 photographs from 2003 and 2004 that Bunnell counts among his best images of genuine lights. They found errors in the recorded bearings and times, and matched every track they could check to vehicles on Nopal/Escondido Road across Mitchell Flat and on ranch roads farther south, 8 to 30 km away. Bunnell's reply, printed with the report, disputes their reading⁠[7].

The earliest published picture found is an uncredited strip at the foot of the 1957 Coronet article: one bright light low against dark mountains, beside a road and a line of poles⁠[4]. The earliest photograph found with its details on record is James Crocker's time exposure of September 1986, taken about 10 miles into Mitchell Flat with a 50 mm lens at f/1.8 for under three minutes; its light traces loops, and lights at the upper right were taken to be cars on US 67⁠[14]. In 1989 night-viewing equipment used for Unsolved Mysteries recorded a globe of light on Mitchell Flat that was later identified as a train's headlamp⁠[7].

Systematic pictures came with the instrumented studies. The UT Dallas students filmed from the viewing area in May 2004⁠[2]. Bunnell's 35 mm time exposures of 2003 and 2004, which he counts among his best images of genuine lights, are reproduced in the 2020 re-analysis beside Google Earth views of the roads they match⁠[7]. His unattended cameras' stacked frames of 3 June 2005 show the bright object with stars, an aircraft track and a mercury-vapour lamp 16 km away for scale⁠[8], and the 2008 Texas State campaign paired video with spectra⁠[5]. None of these pictures is freely licensed, so they are linked from their artifact pages rather than shown here.

The pictures shown are visitors' photographs from the viewing area, all under free licences: a point of light low on the horizon at dusk, and the viewing centre at night.

Headlights. On the evidence of every instrumented study, the lights seen towards US 67 and the Chinati Mountains are the headlights of vehicles on the highway⁠[2]⁠[5]⁠[7]. Vehicles on ranch roads across Mitchell Flat, trains and fires account for others⁠[7]⁠[5]. The idea is not new: Coronet in 1957 already weighed a mirage of artificial lights, and set it aside only because the light was said to predate any light brighter than a kerosene lantern⁠[4].

Refraction and mirages. Distance alone does not explain why headlights seem to hover, jump and split. Layers of cold and warm air bend light, lifting distant lights into view and making them shimmer⁠[7]; the Handbook of Texas calls this the most plausible explanation⁠[1]. Dunning attributes the lights' behaviour to a superior mirage, having withdrawn an earlier suggestion of a Fata Morgana as unlikely at Marfa⁠[15], and Darack describes refraction and several kinds of mirage acting on headlights on US 67⁠[16]. An airborne survey in 2000 proposed instead that headlights reflect off curved, reflective soil beside the highway; Bunnell replied that the lights are seen directly and flicker as the road bends and passes behind terrain⁠[7].

Natural light sources. Those who think a residue is real have offered several mechanisms. Bunnell argues for a light with electric-plasma and burning qualities and a geological cause⁠[17]; the plasma physicist Yoshi-Hiko Ohtsuki compared such lights to ball lightning and kept cameras running at Marfa in 1989 and 1992⁠[7]. Stephan found that burning methane could power many but not all of Bunnell's observations, and with colleagues judged a vortex-fireball model consistent with the 2005 object⁠[18]⁠[8]. Ball lightning from piezoelectric effects in quartz bedrock has also been suggested; Dunning rejects it because no triangulation has ever located the lights⁠[15]. No study reviewed here tests any of them against a recorded light.

The unexplained remainder. What is left is a handful of witness accounts and the 2005 object. Stephan and colleagues judge a portable lamp unreasonable and argue against a power-line arc, but a 14.4 kV distribution line crosses the object's error ellipse and the local electricity co-operative's manager called an arc "not out of the question"⁠[8]. Borraz and Ballester Olmos conclude that there is no objective evidence of an unexplained phenomenon⁠[7].

The tools exist. Two or more cameras with clocks and bearings checked against the stars would turn sightings into positions, and a published catalogue of every detection, classified against roads, ranch lights, trains, aircraft and the sky with the rules fixed before the data are seen, would show whether any residue exists at all⁠[7]. Oxygen-band spectroscopy can give the distance of a light from a single site, and a resolved spectrum would separate lamps, flames and glowing air⁠[5]. For the 2005 object, the co-operative's fault records for that night would test the arc directly⁠[8]. For the history, a search of Presidio County newspapers and papers from before about 1920 would show whether anyone wrote of the lights before there were cars to make them⁠[3].