Comet - Usually a solid cylinder of composition, manufactured in a mold. Comets frequently leave a trail of sparks as they rise in the air, and they sometimes burst into smaller fragments at their zenith. A pellet of pyrotechnic composition that is ignited and propelled from a mortar tube by a charge of black powder. The comets pictured here do not have a burst at the zenith.They can be used outdoors and in arenas that have high ceilings.