HR: 0830h
AN: P51C-0458    [PDF]
TI: Modeling Electrostatic Discharges Near the Surface of Mars
AU: * Krauss, C E
EM: corinne.krauss@colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309 United States
AU: Hor\'{a}nyi, M
EM: mihaly.horanyi@colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309 United States
AU: Hor\'{a}nyi, M
EM: mihaly.horanyi@colorado.edu
AF: Dept. of Physics, University of Colorado, Boulder, CO 80309 United States
AU: Robertson, S
EM: scott.robertson@colorado.edu
AF: Dept. of Physics, University of Colorado, Boulder, CO 80309 United States
AB: Due to the prevalence of Martian dust devils and dust storms, an understanding of the underlying physics of electrical discharges in Martian dust is critical to future Mars exploratory missions. Mars's low atmospheric pressure and arid, windy environment suggest that the dust near the surface of Mars is more susceptible to triboelectric charging than terrestrial dust. When dust particles come into contact, charge can be transferred between the grains. Wind-driven dust studies (Stow, 1969) show that in the case of particles with identical compositions, the particle with the larger radius in a collision preferentially becomes positively charged. Upwinds within a dust cloud can carry the lighter, negatively-charged particles to higher altitudes. The stratification of particle sizes causes an electric dipole to form. When the electric potential within the cloud exceeds the breakdown voltage of the surrounding atmosphere, a discharge occurs. We have created a simple theoretical model to examine the creation of discharges due to triboelectric charging near the surface of Mars. The model results are compared to our laboratory experiments which demonstrate that discharges can be created via vertical charge separation in a simulated Martian environment. When JSC-Mars-1, a Martian regolith simulant, is vertically dropped in a low-pressure CO2 atmosphere, electrical discharges are both visually and electronically detected. Measurements of the frequency and intensity of these discharges show that they can occur under conditions expected on the Martian surface. This work is supported by NASA Space Science GSRP, NGT5-50345.
DE: 5409 Atmospheres--structure and dynamics
DE: 5415 Erosion and weathering
DE: 6213 Dust
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting