A
Whistler is a low frequency radio wave generated by
lightning.
[1] (
http://www.loscrittoio.it/Pages/MM-0700.html). In addition to Earth they have been received from
Jupiter showing the presence of lightning there.
- Whistlers and Related Ionospheric Phenomena, Robert A. Helliwell, Stanford University Press, Stanford, California, 1965. See also Whistlers and VLF Emissions by the same author. (These are best sought in a library)