A search for large meteoroids in the Perseid stream

We report on two surveys conducted during the times of Perseid shower maximum in 1997 and 1998. The first survey entailed the video monitoring of the Moon's disk with the intent of recording the optical flashes that should result when large meteoroids strike the lunar surface. The second survey consisted of a combination video camera and very low frequency (VLF) radiowave receiver system capable of detecting electrophonic meteors during their ablation in the Earth's atmosphere. Using standard ablation theory, we find that for a Perseid meteoroid to be capable of generating electrophonic sounds, it must have an initial mass in excess of 495 kg. We also find, as a result: of the;surveys, an upper limit of 2 x 10(-17) m(-2) s(-1) to the flux of electrophonic Perseid meteors entering the Earth's atmosphere. Although our study indicates that large, meter-sized meteoroids must, at best, be sparsely distributed within the Perseid stream, we briefly discuss some tantalizing lines of evidence, found from within the astronomical literature, that hint at their true existence.