a meteor shower is the result of an interaction between a planet, such as earth, and streams of debris from a comet. comets are dirty snowballs, made up of rock embedded in ice, orbiting the sun. each time a comet swings by the sun in its orbit, some of its ice vaporizes and meteoroids will be shed. the meteoroids spread out along the entire orbit of the comet to form a meteoroid stream, also known as a "dust trail".