We all know from the basic science class that light travels at a faster speed than light and hence we can see lightning first and then hear the sound. But for centuries, skywatchers have reported seeing and simultaneously hearing meteors whizzing overhead. How is that possible? Isn’t that a paradox?
Finally, Scientists have an explanation for this!
The sound waves aren’t coming from the meteor itself, atmospheric scientists Michael Kelley of Cornell University and Colin Price of Tel Aviv University propose April 16 in Geophysical Research Letters. As the leading edge of the falling space rock vaporizes, it becomes electrically charged. The charged head produces an electric field, which yields an electric current that blasts radio waves toward the ground. As a type of electromagnetic radiation, radio waves travel at the speed of light and can interact with metal objects near the ground, generating a whistling sound that people can hear.
Just 0.1 percent of the radio wave energy needs to be converted into sound for the noise to be audible as the meteor zips by, the researchers estimate. This same process could explain mysterious noises heard during the aurora borealis, or northern lights (SN: 8/9/14, p. 32). Like meteors, auroras have been known to emit radio wave bursts.
M.C. Kelley and C. Price. On the electrophonic generation of audio frequency sound by meteors. Geophysical Research Letters. Published online April 9, 2017. doi: 10.1002/2017GL072911.