Out in West Texas, on a wide shoulder of Highway 90 in the desert, curious people gather most every night to view a ghostly phenomenon.

As dusk begins to fall, strange lights appear to hover in the air and then disappear unprompted. The lights have been described as otherworldly. Some find them friendly, and others, sinister. Witnesses claim to see the lights dart in one direction or another, change color, and apparently dissolve just as swiftly as they appeared. The Marfa Lights, as they’re known, are a largely mysterious phenomenon that have confounded and intrigued Texans for generations. But just what exactly are they? Let’s do some research.

Real or imaginary?

Flickr/Nicolas Henderson

First and foremost it’s important to point out that the lights are not a figment of the collective imagination of a gullible public. The Marfa Lights have been well-documented by scientists and celebrities. If you go to the Marfa Light Viewing Center, you are likely to see them for yourself. James Dean is said to have been so obsessed with them during the filming of the movie Giant that he would keep a telescope on him at night to catch glimpses of them.

Marfa Lights Viewing Center Image via Yelp

Ghost lights are an ancient phenomenon that occur worldwide. Some people call them will-o-the-wisps, while others refer to them as swamp lights or orbs. It’s hard to say exactly when the Marfa lights first appeared. There are reports of sightings dating back to the 19th century, but the first known printed account of them showed up in a 1957 issue of Coronet Magazine, where they were referred to as “the Texas Ghost Lights.”

Supernatural or simply nature?

Image via Yelp

Theories abound as to just what causes them. Some people believe the lights are paranormal in essence. That they are perhaps ethereal spirits, the luminous remains of lost souls. Some posit that they are alien in nature, possibly UFOs. The skeptics tend to believe the lights are merely atmospheric reflections of campfires and the headlights of cars passing on a nearby roadway.

There are two notable studies on the Marfa Lights. One was done by Society of Physics students at the University of Texas at Dallas in 2004. Another study was conducted four years later by a group of scientists from Texas State University. The Texas State scientists spent 20 nights using spectroscopic technology to observe the lights. Both studies came to similar conclusions, that the Marfa Lights were most likely caused by the headlights of cars driving by on Highway 67, or by small campfires in the distance.

Flickr/Jon Hanson

Although, some people who have seen the lights vehemently deny this solution. Michael Hall wrote a piece on the subject for Texas Monthly in 2006 entitled “The Truth is Out There.” Hall’s article explored both magical and scientific explanations for the lights.

“My wife and I got married in Alpine six years ago, and the night before, the wedding party wound up at the viewing area. Alcohol was involved, and so was a lot of loud talk. There were more than a dozen of us, and just as a funny movie is funnier with a group of friends, so is a mystery more mysterious. We all agreed—no way those were car lights,” Hall wrote.

Hall wanted badly to believe, but after doing his own research (involving telescopes, binoculars, experts, first-hand testimony and even strobe lights) even he had his doubts.

Some people enjoy the mystery of the lights even more than the lights themselves, though. Julie Mangum saw the lights during her time attending Sul Ross University in Alpine. “It’s the strangest thing to ponder. It absolutely blows my mind just like how space never ends, or like what does it mean to not exist. You don’t always see them when you go and they never are the same every time you’re there. It’s really a great mystery and I don’t know if I really want it solved.”

Could they be a desert mirage?

Image via Wikipedia

In general, ghost lights are considered evasive and mysterious, popping up in random places in the dark of night with few witnesses. However, in Texas, the Marfa Lights are easily spotted from the same location nearly every night. That would suggest that what we’re seeing is not supernatural, but something rational that perhaps has been distorted, causing it to seem unfamiliar.

One way that the Marfa Lights could be car lights and also appear mystical is if they were being disguised through an optical illusion. There is one such optical illusion that is actually very common in most parts of Texas. In fact, you’ve probably experienced it yourself. Picture this: you’re driving down a long stretch of highway in the summer. The road is baking with heat. The temperature is creeping up toward the triple digits, and there is not a cloud in the sky. Suddenly, up ahead the road appears to be wet. Did a sudden shower move through the area right before you drove in? No, that can’t be right either, because as you near the watery section of road, it appears to dry before your eyes.

Flickr/Einar Jørgen Haraldseid

What you’re actually seeing is an optical illusion commonly known as “heat haze” or “heat shimmer.” It occurs when extreme heat near the surface of the road refracts the light from the sky. In simple terms, the ground becomes a mirror and reflects the sky. During daylight hours when there’s not much on the horizon, your brain interprets this heat haze as water. However, the haze can actually create a mirror image (also known as an inverted mirage) when it’s in front of something large like a mountain. The effect of which is to make something in the distance seem to appear upside down, like it’s being reflected in a pool of water that simply isn’t there. Now imagine what that would do to car headlights traveling along a road, or campfire lights at night.

Paradoxically, a mirage could even be to blame when the weather is cold. Cold air mirages are known as “superior mirages.” They happen when the air close to the ground is colder than the air above it. They are more common in polar regions than in the arid West Texas desert, but it’s one possible explanation.

However, you also have to take into consideration that there were reports of ghost lights in this area in the 1850’s, before Texas even had roads. Or cars. Could it really be lost souls? Maybe. No one really knows what happens after this life. It could be camp-fires. Hell, that close to New Mexico, it could really be aliens. We may never know.