ELF/VLF radiation produced by the 1999 Leonid meteors

For more than 200 years large meteors entering the atmosphere have been observed to produce audible sounds simultaneously with the optical flash. Since sound waves travel much slower that visible light, the only explanation was that electromagnetic waves produced by the meteors induce a vibration in a transducer close to the observer, producing an audible sound, known as electrophonics. To check this hypothesis, continuous measurements of low frequency electromagnetic waves were performed during the Leonids meteor storm on the night of 18 November, 1999. The analyses of the data indicate distinct electromagnetic pulses produced by the incoming meteors. Many of the weaker incoming meteors that could not be seen visibly were also detected electromagnetically, with a peak rate of approximately 15,000 meteors per hour occurring at the peak of the storm, nearly 50 times the visible rate.