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Accession Number N20120010234
Title Lunar Surface Electric Potential Changes Associated with Traversals through the Earth's Foreshock.
Publication Date 2011
Media Count 17p
Personal Author G. T. Delory H. K. Hills J. Espley J. S. Halekas J. W. Freeman M. R. Collier R. Vondrak T. J. Stubbs W. M. Farrell
Abstract We report an analysis of one year of Suprathermal Ion Detector Experiment (SIDE) Total Ion Detector (TID) resonance events observed between January 1972 and January 1973. The study includes only those events during which upstream solar wind conditions were readily available. The analysis shows that these events are associated with lunar traversals through the dawn flank of the terrestrial magnetospheric bow shock. We propose that the events result from an increase in lunar surface electric potential effected by secondary electron emission due to primary electrons in the Earth's foreshock region (although primary ions may play a role as well). This work establishes (1) the lunar surface potential changes as the Moon moves through the terrestrial bow shock, (2) the lunar surface achieves potentials in the upstream foreshock region that differ from those in the downstream magnetosheath region, (3) these differences can be explained by the presence of energetic electron beams in the upstream foreshock region and (4) if this explanation is correct, the location of the Moon with respect to the terrestrial bow shock influences lunar surface potential.
Keywords Bow waves
Earth(Planet)
Electric potential
Electrons
Interplanetary medium
Interplanetary shock waves
Ions
Lunar surface
Magnetosheath
Moon
Position(Location)
Secondary emission
Solar wind
Surface properties
Upstream


 
Source Agency National Aeronautics and Space Administration
NTIS Subject Category 54 - Astronomy & Astrophysics
84B - Extraterrestial Exploration
Corporate Author Goddard Space Flight Center, Greenbelt, MD.
Document Type Journal article
Title Note N/A
NTIS Issue Number 1226
Contract Number N/A

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