International Meteor Organization - Science note on the Leonids 2000

The Leonids

The Leonids are caused by a stream of predominantly very small particles, less than 1 mm in size, which orbit the Sun with a period of 33 years, together with their parent comet, Tempel-Tuttle. The orbit of the Leonid particles happens to intersect the Earth's orbit. Each year around 17 November, when the Earth is at this intersection, Leonid particles may enter the Earth's atmosphere and cause meteors. Along the larger part of Comet Tempel-Tuttle's orbit, Leonid particles are scattered sparsely, so that, in most years, we see only a few Leonid meteors per hour. Only in the vicinity of the Comet, the density of Leonid particles is much higher. Consequently, every 33 years, during the years that Comet Tempel-Tuttle revisits our region of the Solar System, much higher Leonid activity is recorded. In some instances, this Leonid meteor shower develops into a real meteor storm!

	Introduction
	Leonids in the past

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Last Update: 08 Sep 2005