Of all of Earth’s unexplained scientific phenomenon, ball lightning is by far the ballest and the lightningest. The term “ball lightning” refers to numerous reported incidents of luminous, usually spherical objects, ranging from pea-sized to several meters in diameter. Ball lightning sightings are often associated with thunderstorms, but lasts much longer than the usual split-second flash of “standard” lightning strikes.
There are many, often widely-varying descriptions of ball lightning. It has been described as traveling in unpredictable trajectories, moving up, down, and sideways, and hovering or moving with or against the wind. Ball lightning has been reported to be attracted to, repelled by, or unaffected by its surroundings, including people, cars, and other objects. It is often described as moving through solid masses, such as wood or metal, without effect; other descriptions have it melting, burning, or otherwise destroying those same materials. Ball lightning has been described as multicolored, transparent, translucent, evenly lit, and radiating flames or sparks; reported shapes include spheres, ovals, rods, disks, and others.
Ball lightning has been reported to disperse in a variety of ways, as well. These include gradually dissipating, absorption into another object, exploding loudly and/or with damaging force, and suddenly vanishing completely. Accounts of its effects on humans also vary greatly, from harmless to lethal.
A list of common properties of “typical” ball lightning includes:
- Ball lightning appears almost simultaneously with the discharge of cloud-to-ground lightning
- Generally spherical, often with fuzzy or undefined edges
- Diameters can range from 1 to 100 centimeters; 10 to 20 centimeters is most common
- They can be seen clearly in daylight; brightness is roughly equivalent to a standard table lamp
- Numerous colors have been observed; red, yellow, and orange are most common
- Sightings can last from one second to well over a minute; brightness remains essentially constant
- Most movement is horizontal, though vertical movement and erratic wandering are not uncommon; some remain stationary
- Ball lightning does not usually generate heat; however, in many cases the disappearance of the ball does cause the liberation of heat
- May move along metal conductors such as wire or fences
- Can appear inside buildings, and pass through closed doors and windows
- Have been reported to appear within metal aircraft, entering and leaving without causing damage
- Unpleasant odors, such as ozone, burning sulfur, or nitrogen oxide, are frequently reported
Effects visually similar to ball lightning have been produced via laboratory experiments; however, it is unknown if these are actually related to any naturally-occurring phenomenon. Owing to its infrequency and unpredictability, scientific data on ball lightning is scarce. As the presumption of its existence is based almost entire on reported public sightings, findings are understandably inconsistent. Despite mankind’s considerable scientific abilities, the true nature of ball lightning is still unknown.