An Impactor Origin for Lunar Magnetic Anomalies

@article{Wieczorek2012AnIO,
  title={An Impactor Origin for Lunar Magnetic Anomalies},
  author={Mark A. Wieczorek and Benjamin P. Weiss and Sarah T. Stewart},
  journal={Science},
  year={2012},
  volume={335},
  pages={1212 - 1215}
}
Bringing Magnetic Materials to the Moon The Apollo missions to the Moon revealed that portions of the lunar crust are strongly magnetized. Lunar rocks are poor at recording the magnetic field, thus these magnetic anomalies have been difficult to explain. Based on numerical simulations of large-scale impacts, Wieczorek et al. (p. 1212; see the Perspective by Collins) show that the vast majority of lunar magnetic anomalies can be explained by highly magnetic materials that originated outside the… 
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References

SHOWING 1-10 OF 117 REFERENCES
Magnetic fields of lunar multi‐ring impact basins
Abstract— We survey the magnetic fields of lunar multi‐ring impact basins using data from the electron reflectometer instrument on the Lunar Prospector spacecraft. As for smaller lunar craters, the
Mapping of crustal magnetic anomalies on the lunar near side by the Lunar Prospector electron reflectometer
Lunar Prospector (LP) electron reflectometer measurements show that surface fields are generally weak in the large mare basalt filled impact basins on the near side but are stronger over highland
Initial mapping and interpretation of lunar crustal magnetic anomalies using Lunar Prospector magnetometer data
Maps of relatively strong crustal magnetic field anomalies detected at low altitudes with the magnetometer instrument on Lunar Prospector are presented. On the lunar nearside, relatively strong
Formation of magnetic anomalies antipodal to lunar impact basins: Two‐dimensional model calculations
The production of large-scale magnetic fields and associated crustal magnetization in lunar basin-forming impacts is investigated theoretically. Two-dimensional numerical models of the partially
A review of lunar paleointensity data and implications for the origin of lunar magnetism
The saturation remanence normalization method of paleointensity estimation has been applied to more than 50 lunar samples, and has been calibrated in terms of standard intensity determinations done
Early Lunar Magnetism
It is uncertain whether the Moon ever formed a metallic core or generated a core dynamo. The lunar crust and returned samples are magnetized, but the source of this magnetization could be meteoroid
Global spherical harmonic models of the internal magnetic field of the Moon based on sequential and coestimation approaches
[1] Three new models of the global internal magnetic field of the Moon based on Lunar Prospector (LP) fluxgate magnetometer observations are developed for use in understanding the origin of the
...
...