Perseids help astronomy....
http://antwrp.gsfc.nasa.gov/apod/ap020816.html
The sodium meteors deposit in the mesosphere make the laser guide star possible...
Space/Science » in reply to Perseid data
http://antwrp.gsfc.nasa.gov/apod/ap020816.html
The sodium meteors deposit in the mesosphere make the laser guide star possible...