Awash in moonlight, the Perseid meteor shower is at present not very easy to see. Some observers have given up on looking, choosing instead to monitor the shower by means of radio. This plot from Dave Swan shows how he is counting more than 300 Perseid radio echoes per hour using a Yagi antenna and 55.25 MHz receiver in Bransgore, UK:

© Dave Swan

In the loudspeaker, each echo sounds like a little "ping." It is the reflection of a distant TV transmitter from the meteor's ionized trail. Forward scatter meteor detection, as this technique is called, is more sensitive than ordinary visual observation. Very small meteoroids are able to create a radio echo without leaving any trace of optical light in the sky. That's why Swan is counting 300 radio Perseids per hour while naked-eye observers are couting no more than about 20. Click here to monitor forward scatter stations around the world.