A randomly occurring meteor, not associated with any meteor shower. Sporadic meteors can be seen on any clear night, with rates varying from perhaps 3–4 meteors/h in the spring to 8–10 meteors/h in the autumn. In addition to this seasonal variation there is also a nightly variation, which results in higher sporadic rates before dawn than in the evening hours. The sporadic background represents an end-point in meteor stream evolution, reached when the meteoroids in a stream become so dispersed that a meteor shower is no longer detectable. Because they are random, sporadic meteors are often considered a useful control sample in shower studies.