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Magnetization of the Lunar CrustMagnetic fields measured by the satellite Lunar Prospector show large scale features resulting from remanently magnetized crust. Vector data synthesized at satellite altitude from a spherical harmonic model of the lunar crustal field, and the radial component of the magnetometer data, have been used to produce spatially continuous global magnetization models for the lunar crust. The magnetization is expressed in terms of localized basis functions, with a magnetization solution selected having the smallest root-mean square magnetization for a given fit to the data, controlled by a damping parameter. Suites of magnetization models for layers with thicknesses between 10 and 50 km are able to reproduce much of the input data, with global misfits of less than 0.5 nT (within the uncertainties of the data), and some surface field estimates. The magnetization distributions show robust magnitudes for a range of model thicknesses and damping parameters, however the magnetization direction is unconstrained. These global models suggest that magnetized sources of the lunar crust can be represented by a 30 km thick magnetized layer. Average magnetization values in magnetized regions are 30-40 mA/m, similar to the measured magnetizations of the Apollo samples and significantly weaker than crustal magnetizations for Mars and the Earth. These are the first global magnetization models for the Moon, providing lower bounds on the magnitude of lunar crustal magnetization in the absence of multiple sample returns, and can be used to predict the crustal contribution to the lunar magnetic field at a particular location.
Document ID
20140005983
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Carley, R. A.
(Edinburgh Univ. United Kingdom)
Whaler, K. A.
(Edinburgh Univ. United Kingdom)
Purucker, M. E.
(Stinger Ghaffarian Technologies, Inc. (SGT, Inc.) Greenbelt, MD, United States)
Halekas, J. S.
(California Univ. Berkeley, CA, United States)
Date Acquired
May 20, 2014
Publication Date
August 1, 2012
Publication Information
Publication: Journal of Geophysical Research-Planets
Publisher: Wiley online
Volume: 117
Issue: E8
Subject Category
Lunar And Planetary Science And Exploration
Report/Patent Number
GSFC-E-DAA-TN9233
Funding Number(s)
CONTRACT_GRANT: NER/S/A/2006/14230
CONTRACT_GRANT: NNG11HP14C
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
Lunar
Crust
Magnetization
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