This image was obtained at the Observatori Astronomic de Mallorca in November of 1998. Some days of the year show a larger number of meteors than usual that all have a common origin. The Leonids are such a meteor stream. The radiant of the Leonids is in the constellation Leo. The radiant is a perspective effect.
All particles move in about the same orbit.
An observer in the middle of the stream sees the meteors fall left and right, above and behind him. However, they all seem to come from a certain direction. That direction is the radiant. The dust trail evolves into a meteoroid stream as a result of perturbations by the major planets. It is not yet known exactly how this process happens.