Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1773565 | Icarus | 2011 | 4 Pages |
Abstract
The non-condensing neutral helium exosphere is at its most concentrated levels on the cold lunar nightside. We show herein that these He atoms are susceptible to impact ionization from primary and secondary electrons flowing in the vicinity of the negatively-charged nightside lunar surface. The secondary electron beams are a relatively recent discovery and are found to be emitted from the nightside surface at energies consistent with the negative surface potential. The effect is to create an electron impact-created ionosphere in nightside regions, possibly especially potent within polar craters.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
W.M. Farrell, J.S. Halekas, T.J. Stubbs, G.T. Delory, R.M. Killen, R.E. Hartle, M.R. Collier,