[meteorite-list] grains of sand

[Paul Gessler]

Was wondering about the statement that shooting stars we see are no bigger 
than grains of sand???
I here it used all the time and haven't  really given it any thought. I 
don't buy it!
I don't think a grain of sand would be able to generate enough light to be 
visible from earth?
Has anyone actually measured these grains of sand? If so how was it done. 
Where did this (factoid)
originate and is there any validity to it?
I could see gravel sized debris producing what we see but not sand and 
smaller.

Any one care to comment?

Paul Gessler