Main page Meteors create trails of ionisation high in the atmosphere as they burn up. A great deal of energy is released as the meteor is destroyed so that even a small meteor can produce a trail that is a mile or so long. These trails can sometimes refract radio waves if they are large enough. However, the free electrons and gas molecules quickly recombine and propagation may only be supported for a few seconds.
This type of anomalous propagation has been successfully used for frequencies near the middle of the HF band (around 15 MHz) well into the VHF part of the spectrum (higher that 100 MHz). The meteor trails need to be about equidistant between the transmitter and receiver; this limits the distance to about 1500 kms.