This month's star chart shows the eastern sky at 1:00 AM on November 17, 1998.  The radiant of the Leonid meteor shower, or meteor storm if we're lucky, rises about 12:30 AM.  Notice,
however, that the meteors move outward from the radiant in all directions.  Thus, some of the
meteors that move upward can be seen well before the radiant rises.

Notice that the meteor trails (the gray arrows) are shorter near the radiant and longer farther
away.  This effect results from the relative motion of the meteors and the earth.  The meteors are in fact moving parallel to each other in a wide stream, but they appear to come from a point (the radiant) in the Sickle of Leo.  The meteors that we see approaching nearly head on have very short paths, and can even appear essentially as bright points, or point meteors (see the picture on p 42, November Sky & Telescope).  The meteors heading well above or below us, or to our left or right, appear to have longer paths.  You can see much the same effect driving in a snowstorm at night, an experience I used to have more often than I wished.

Most of the Leonids are about the size of a grain of sand.  They enter our atmosphere at about
158,000 miles per hour.  For comparison, the earth's orbital velocity around the sun is 67,000
MPH.  Comet Temple-Tuttle (Comet P55, discovered in 1866) throws off the debris that
generates the Leonids.  The comet has a period of 33.25 years, so there's a fair chance of a major storm this year, or maybe next.  Past Leonid storms have produced as many as 150,000 meteors per hour for a short time at the peak.

Here's a web site with an enormous amount of comet info: http://medinfo.wustl.edu/~kronkg/
(also accessible through a link on our BBAS web site).