The leonid shower occurs each november , when the earth ' s orbit takes it through the trail of particles shed by the comet tempel - tuttle as it swings around the sun once every 33 years 當?shù)厍虼┻^"坦佩爾-塔特爾"彗星尾部稠密的彗星碎片帶時,就會出現(xiàn)流星雨現(xiàn)象。這顆彗星在太陽系外圍軌道運行,它的運行周期是33年。