The Marfa lights are visible every clear night between the Marfa and Paisano Pass in Texas. At times they appear colored as they twinkle in the distance. They move about, split apart, melt together, disappear, and reappear. Residents have watched the lights for over a hundred years. The first historical record of them occurred in 1883 when a young cowhand saw flickering lights while he was driving cattle through Paisano Pass. He was told by other settlers that they often saw the lights, but when they investigated they found no ashes or other evidence of a campsite.
World War I observers feared that the lights were intended to guide an invasion. During World War II pilots training at a nearby airfield looked for the source of the elusive lights from the air, again with no success.
Over the years many explanations for the lights have been offered, ranging from an electrostatic discharge, swamp gas, or moonlight shining on veins of mica, to ghosts of conquistadors looking for gold.
The most plausible explanation is that the lights are an unusual phenomenon similar to a mirage, caused by an atmospheric condition produced by the interaction of cold and warm layers of air that bend light so that it is seen from a distance but not up close. In recent years the lights have become a tourist attraction.
The Texas State Highway Department has constructed a roadside parking area nine miles east of Marfa on U.S. Highway 90 for motorists to view the curious phenomenon. The lights have made the little town of Marfa famous. To draw more tourists for the mysterious lights, the city has begun an annual festival to celebrate them.