A search for large meteoroids in the Perseid stream

We report on two surveys conducted during the times of Perseid shower maxim um 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 re sult when large meteoroids strike the lunar surface. The second survey cons isted of a combination video camera and very low frequency (VLF) radiowave receiver system capable of detecting electrophonic meteors during their abl ation in the Earth's atmosphere. Using standard ablation theory, we find th at 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 resu lt: of the;surveys, an upper limit of 2 x 10(-17) m(-2) s(-1) to the flux o f electrophonic Perseid meteors entering the Earth's atmosphere. Although o ur study indicates that large, meter-sized meteoroids must, at best, be spa rsely distributed within the Perseid stream, we briefly discuss some tantal izing lines of evidence, found from within the astronomical literature, tha t hint at their true existence.