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Thorium Anomalies in the NW Quadrant of the South Pole-Aitken BasinThe relatively high concentrations of Th near the Imbrium antipode in the South Pole-Aitken (SPA) basin might represent Imbrium ejecta, a consequence of convergence of Th-rich material ejected by the Imbrium impact that occurred in the Th-rich Procellarum KREEP Terrane. Here, we present landing positions for 7500 fragments ejected from Imbrium obtained by three-body (Earth-Moon-fragment) numerical integration for uniformly selected azimuthal launch positions, ejection angles of 45 deg, and velocities from 0.95 to 0.99 lunar escape. This provides an estimate of the density of infalling ejecta fragments to be expected in the vicinity of the Imbrium antipode. Similar calculations for 35 and 50 deg leave large empty regions surrounding the antipode.
Document ID
20040068005
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Haskin, Larry A.
(Washington Univ. Saint Louis, MO, United States)
McKinnon, William B.
(Washington Univ. Saint Louis, MO, United States)
Benner, Lance A. M.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Jolliff, Bradley L.
(Washington Univ. Saint Louis, MO, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2004
Publication Information
Publication: Lunar and Planetary Science XXXV: Planetary Formation and Early Evolution
Subject Category
Lunar And Planetary Science And Exploration
Funding Number(s)
CONTRACT_GRANT: NAG5-10485
Distribution Limits
Public
Copyright
Public Use Permitted.
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