Measurements of electrical discharges in Martian regolith simulant

Due to the prevalence of Martian dust devils and dust storms, an understand ing of the underlying physics of electrical discharges in Martian dust is c ritical to future Mars exploratory missions. Measurements on the charging o f single dust grains show that particles of Martian regolith simulant can h ave large electric potentials due to triboelectric charging. As a result of this charging, agitated Martian regolith simulant in a low-pressure CO2 at mosphere produces electrical discharges. Under extremely dark viewing condi tions, electrical discharges are visually observed at pressures between 0.1 and 50 torr, Measurements of the frequency and intensity of these discharg es as a function of pressure (from 0.1 to 5 torr) and stirring speed (corre sponding to wind speeds from 0.1 to 2.6 m/s) show that discharges occur at pressures and wind speeds similar to those expected on the Martian surface.