The search for unexplained "spook lights"S

Mysterious lights are seen at sunset and during the night. They reappear again and again, in all kinds of weather conditions, causing no damage. What could they be? Have you seen them?

If you live around Joplin, St Louis, or Sarasota, you may have seen an interesting phenomenon. Spook lights are lights without obvious source that appear in the evening or at night. They are usually only seen from a distance, and endure a short time before disappearing. They're regularly seen all around the United States and Canada, and many sites have documented sightings of their lights that go back to the 1800s.

Complicating the explanations of spook lights is the wide variation in their behavior. Some are said to wave back and forth, the way ground crews wave in planes. Others are supposed to skitter over tree tops, without causing fires. Some split in two. Some just sit still and glow. There can be one at a time, or more than one. They're usually white, but can be different colors.

The search for unexplained "spook lights"S

The most handy explanation for spook lights is the old physics favorite; ball lightning. The lightning itself is not entirely explained, although physicists did create something very similar to it by heating pieces of silica until they emitted a glowing vapor. Ball lightning, however, often leaves scorch marks, and sometimes burns things outright. Spook lights don't do that. And of course, ball lightning is very rare. Spook lights are downright common in some areas.

The search for unexplained "spook lights"

Natural gases are another popular explanation. Eruptions of natural gas offer an explanation for why the lights show up in the same places over and over again; wherever natural gas meets frequent human travel, people could see lights. Natural gas still needs something to set it alight. Atmospheric conditions like drought or lightning might do it, but people have noticed spook lights in all kinds of weather conditions.

The final possible explanation has to do with minerals in the earth interacting with fault lines in the area. As the fault shifts, rocks inside scrape the minerals and generates light, the way rubbing certain materials together gives off sparks. The light is refracted, and appears on the horizon.

None of these explanations fit the exact behavior of spook lights, but it's possible that all of them together might. The phenomenon has been seen by many different people, and "a light at night" can't be explained away. But one reason the accounts of spook lights vary so much might be just that people are describing different phenomena.

If you have witnessed these lights and have a story or a theory, please let us know.

Via The Unmuseum, Modern Mysteries, Legends of America, Prairie Ghosts, and The Astronomy Café.