Naturally, this debris is most plentiful close to, and behind the comet. For one or two years after perihelion, the point where the comet is closest to the Sun, the showers are especially strong. The strength of the meteor shower or storm is indicated by the rate that particles are observed in the sky. Image above is one frame of meteor recorded from a NASA balloon flight. Click for 131KB animated gif Movie highlights from the balloon over Alabama.
Storms are much stronger and have counts in the hundreds.
The strongest recorded Leonid meteor storm, in 1966, provided over 150,000 counts per hour for about three hours. The incoming rain of particles is not a concern to anyone on the Earth, since the particles burn up high in the atmosphere. Orbiting satellites and spacecraft, however, can be affected by meteor impacts during a shower or storm. Although each particle is very small, typically about the size of a grain of sand, it is moving extraordinarily fast, about 155,000 mph. At this speed a typical grain of sand could have the same impact as a .22 caliber bullet.