However, some have been seen traveling horizontally under overhead cloud cover or in directly front of distant mountains, sometimes moving at great speed.   Moreover, many sightings have been reported by very reliable observers, often with simultaneous tracking on radar.   Many sighting were reported by multiple witnesses, who were often strangers to each other at the time.  There are quite a number of photos and motion pictures that have never been shown to be fraudulent.

       Sightings of ball lightning and UFO's appear to have much in common:
1)    Radiate similar colors, with white the commonest,  violet the rarest.
2)    Light intensity can vary from faint to extremely bright.
3)    May exhibit a solid or even metallic appearance.
4)    May exhibit a marked pulsing effect.
5)    May have a bright inner core and a diffuse outer layer.
6)    Many appear to be rapidly spinning about a central axis,
7)    Most consist of a shape of rotation (spheres,  saucers, cones,  etc.)
8)    May hover or exhibit high velocity, sometimes thousands of miles per hour
9)    May show near instantaneous acceleration or sharp turns at 80 G's
10)  Often exhibit a wobbling, or " falling leaf " motion.
11)  Often associated with a pungent odor, like sulfur or ozone.
12)  Often explode violently, leaving no residue or debris.
13)  Both strongly correlate with geological seismic activity.
14)  May give off electricity, such as lightning or apparent electrical arcs.
15)  Associated with failures of gas engines, electronics, or camera film.
16)  Associated with symptoms to nervous systems, such as paralysis or amnesia.
17)  May cause what appear to be apparent radiation burns.
18)  Both tend to occur during the same time of day.