Askaryan effect

Etymology
Named after Soviet-Armenian physicist, who postulated it in 1962.

Noun

 * 1)  The phenomenon whereby a particle traveling faster than the phase velocity of light in a dense dielectric (such as salt, ice or the lunar regolith) produces a shower of secondary charged particles which contains a charge anisotropy and emits a cone of coherent radiation in the radio or microwave part of the electromagnetic spectrum.