Re: How far away from us are 'shooting stars' as we observe them?

Hi Jay,
  If you do web searches for 'meteors' you'll find lots of information, 
particularly with all the recent interest in the Leonid meteor storm a few 
days ago.  One good one which will help you get started is the Sky and 
Telescope magazine meteor page  http://www.skypub.com/
sights/meteors/meteors.shtml
As you know, 'shooting stars' are caused by tiny pieces of rock and dust 
burning up in the Earth's atmosphere.  They start to burn up when the 
atmospheric pressure becomes great enough to start to slow them down and 
that can vary a bit depending upon the size of the grain.  It's usually 
50-75 miles high.  Thus a particular shooting star will be visible for up 
to 100-200 miles around I would guess.  It might be a good project for your 
students to try and estimate how far away you can be on the curved surface 
of the Earth before you can no longer see something 50 miles high.