HR: 1340h
AN: SH43A-1157    [Abstracts]
TI: Solar Wind-driven Dust Transport in the Lunar Exosphere
AU: Vondrak, R R
EM: Richard.R.Vondrak@nasa.gov
AF: NASA Goddard Space Flight Center, Solar System Exploration Division, 8800 Greenbelt Road, Greenbelt, MD 20771 United States
AU: * Stubbs, T J
EM: Timothy.J.Stubbs.1@gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Solar System Exploration Division, 8800 Greenbelt Road, Greenbelt, MD 20771 United States
AU: Farrell, W M
EM: William.M.Farrell@nasa.gov
AF: NASA Goddard Space Flight Center, Solar System Exploration Division, 8800 Greenbelt Road, Greenbelt, MD 20771 United States
AB: From the Apollo era there is much evidence to show that lunar horizon glow observed at the terminator is caused by sunlight scattered by dust grains originating from the surface. The dust grains and lunar surface are electrically charged by the Moon's interaction with the local plasma environment and the photoemission of electrons due to solar UV and X-rays. This causes the like-charged surface and dust particles to repel each other, and creates a near-surface electric field. We have previously proposed a simple dynamic dust "fountain" model to explain observations of submicron-sized grains "lofted" to altitudes of up to 100km. In this model charged dust grains follow ballistic trajectories, subsequent to being accelerated upwards through a narrow sheath region by the surface electric field. Discussed here are improvements to the simple fountain model in order to make it more realistic; in particular, we investigate the effects of different surface electric field profiles and the cohesion of the grains on the lunar surface. These dust grains in the exosphere will affect the optical quality of the lunar environment for astronomical observations and interfere with exploration activities.
DE: 2732 Magnetosphere interactions with satellites and rings
DE: 2780 Solar wind interactions with unmagnetized bodies
DE: 5465 Rings and dust
DE: 6250 Moon (1221)
DE: 7849 Plasma interactions with dust and aerosols (2461)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005