An Impactor Origin for Lunar Magnetic Anomalies

  title={An Impactor Origin for Lunar Magnetic Anomalies},
  author={Mark A. Wieczorek and Benjamin P. Weiss and Sarah T. Stewart},
  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… 
Moonstruck Magnetism
It is proposed that many of the Moon's magnetic anomalies originate from highly magnetic deposits of a giant asteroid that collided with the Moon early in its history.
Impactor material records the ancient lunar magnetic field in antipodal anomalies
Simulation of oblique impacts of 100-km-diameter impactors at high resolution shows that an ~700 m thick deposit of potentially iron-rich impactor material accumulates at the basin antipode, consistent with a dynamo field strength of at least several tens of microtesla during the basin-forming epoch.
Iron Abundances in Lunar Impact Basin Melt Sheets From Orbital Magnetic Field Data
Magnetic field data acquired from orbit shows that the Moon possesses many magnetic anomalies. Though most of these are not associated with known geologic structures, some are found within large
South Pole Aitken Basin magnetic anomalies: Evidence for the true polar wander of Moon and a lunar dynamo reversal
The analysis of the Lunar Prospector magnetic data over South Pole Aitken basin reveals two categories of magnetic anomalies with distinctly different polarities. Modeling the anomalies in terms of
The lunar dynamo
It has now been established that a dynamo magnetic field likely existed on the Moon from at least 4.5 billion to 3.56 billion years ago, with an intensity similar to that at the surface of Earth today.
Is the Lunar Magnetic Field Correlated With Gravity or topography?
Magnetic field measurements made from orbit show that there are strong magnetic anomalies on the Moon, but many of these show no clear correlation with known geological processes. Given that the
Was the moon magnetized by impact plasmas?
Although impact plasmas can transiently enhance the field inside the Moon, the resulting fields are at least three orders of magnitude too weak to explain lunar crustal magnetic anomalies, leaving a core dynamo as the only plausible source of most magnetization on the Moon.
Magnetic Anomalies in Five Lunar Impact Basins: Implications for Impactor Trajectories and Inverse Modeling
A recent large‐scale map of the lunar crustal magnetic field is examined for the existence of magnetic anomalies internal to ringed impact basins. It is found that, of 25 basins with upper


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