http://www.youtube.com/watch?v=KVDU-6opEqAJa ominaisuuksia (sori Teiskon murteella):
* They frequently appear almost simultaneously with cloud-to-ground lightning discharge
* They are generally spherical or pear-shaped with fuzzy edges
* Their diameters range from 1-100 cm, most commonly 10-20 cm
* Their brightness corresponds to roughly that of a domestic lamp, so they can be seen clearly in daylight
* A wide range of colors have been observed, red, orange and yellow being the most common.
* The lifetime of each event is from 1 second to over a minute with the brightness remaining fairly constant during that time
* They tend to move, most often in a horizontal direction at a few meters per second, but may also move vertically, remain stationary or wander erratically.
* Many are described as having rotational motion
* It is rare that observers report the sensation of heat, although in some cases the disappearance of the ball is accompanied by the liberation of heat
* Some display an affinity for metal objects and may move along conductors such as wires or metal fences
* Some appear within buildings passing through closed doors and windows
* Some have appeared within metal aircraft and have entered and left without causing damage
* The disappearance of a ball is generally rapid and may be either silent or explosive
* Odors resembling ozone, burning sulfur, or nitrogen oxides are often reported