 Initially conceived as a way for citizens to participate in science and as a supplement to professionally manned optical and radio tracking stations, Moonwatchers around the world found themselves an essential component of the professional scientists’ research program.Using specially designed telescopes, hand-built or purchased from vendors like Radio Shack, scores of Moonwatchers nightly monitored the skies.Their prompt response was aided by the extensive training they had done by spotting pebbles tossed in the air, registering the flight of moths, and participating in national alerts organized by the Civil Air Patrol.