On the night of August 11 and well into the next day, Earth will make its annual passage through the bulk of the debris shed by a comet known as Swift-Tuttle. Much of the debris is composed of dust-sized grains, but when these fragments come plunging into our atmosphere they can create a dazzling meteor display. Not only are the meteors fascinating to watch, they also leave short-lived streams of ionized gas in their wake. As hams have known for years, these meteor trails are excellent reflectors of radio waves.