Earth passes annually through cometary orbits, which are littered with leftover particles.
The consequent meteor showers are plentiful and heavy.
The showers known as the Perseids display up to sixty-eight meteors an hour at its peak around August 12.
The Eta Aquarids peak around May 5, average about ten an hour, up to a maximum of twenty, and is associated with Halley’s comet.
The Leonids, peaking around November 17, vary from year to year, but are usually weak.
In 1866, 1933, and 1966, however, they stormed.
In 1966, meteors rained at a peak rate of 60,000 to 100,000 per hour, though the shower lasted only 40 minutes.
Another Leonid storm was expected in 1999, and was indeed spectacular.