Experimental evidence for electrostatic discharging of dust near the surface of Mars

Abstract

Laboratory experiments have shown that single non-conductive dust grains can attain large electric potentials due to triboelectric charging. When grains within a dust cloud interact, they become charged. An electric field forms when upwinds within the cloud cause a separation of large and small particles. We have performed laboratory experiments to determine the necessary conditions for triboelectric charging in a cloud of Martian regolith simulant to break down a low-pressure CO2 atmosphere and create electrical discharges. The range of pressures and the simulated wind speeds over which discharges are observed have been determined. The effects of particle-size distribution on the observed discharge rates are also discussed.