Interpretation of the microwave non-thermal radiation of the Moon during impact events

Abstract

Part of Special Issue "Precursory phenomena, seismic hazard evaluation and seismo-tectonic electromagnetic effects"Abstract. The results of recent observations of the nonthermal electromagnetic (EM) emission at wavelengths of 2.5 cm, 13 cm, and 21 cm are summarized. After strong impacts of meteorites or spacecrafts (Lunar Prospector) with the Moon's surface, the radio emissions in various frequency ranges were recorded. The most distinctive phenomenon is the appearance of quasi-periodic oscillations with amplitudes of 3-10 K during several hours. The mechanism concerning the EM emission from a propagating crack within a piezoactive dielectric medium is considered. The impact may cause the global acoustic oscillations of the Moon. These oscillations lead to the crackening of the Moon's surface. The propagation of a crack within a piezoactive medium is accompanied by the excitation of an alternative current source. It is revealed that the source of the EM emission is the effective transient magnetization that appears in the case of a moving crack in piezoelectrics. The moving crack creates additional non-stationary local mechanical stresses around the apex of the crack, which generate the non-stationary electromagnetic field. For the cracks with a length of 0.1-1 µm, the maximum of the EM emission may be in the 1-10 GHz range.

Prospects of probing the radio emission of lunar UHECRv events

“…In table 4 common radio emissions in the lunar environment are compared with radiation of UHECRv events. Impact of lunar dust, charged particles, and micro-meteorites generate radio pulses which cover a broad range of spectrum from kHz to GHz regime (Grimalsky et al, 2004). It has local peaks at kHz regime which are detectable by the antenna, Dust camera, and Langmuir probe (Klein-Wolt et al, 2012).…”

Analysis of explosions and seismic phenomena based on electromagnetic cracking of piezoelectric and piezomagnetic plates

“…In Grimalsky et al (2004), the theory was used to explain events for Jupiter, providing a good test of such calculations for other phenomena. Herein, analysis of the differences in emission from piezoelectric and piezomagnetic plates in cases of explosions versus seismic and volcanic phenomena is presented, enabling use of this analysis method for phenomenon identification.…”

On the nature of short-period variations of the Lunar radio emission in the centimeter wave range

“…Короткопериодические вариации радиопотока от Луны [15,18,19] связываются с явлением радиоэмиссии, сопровождающей трещинообразование хрупких пород [16]. Элементарные оценки показывают, что для трещины с характерным размером 0.1-0.01 мм характерен спектральный максимум в диапазоне метровых волн.…”