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The moon

, Volume 7, Issue 3–4, pp 322–341 | Cite as

Orbital mapping of the lunar magnetic field

  • L. R. Sharp
  • P. J. ColemanJr.
  • B. R. Lichtenstein
  • C. T. Russell
  • G. Schubert
Article

Abstract

Magnetometer data obtained during the first four lunations after the deployment of the Apollo 15 subsatellite have been used to construct contour maps of the lunar magnetic field referred to 100 km altitude. These contour maps cover a relatively small band on the lunar surface. Within the region covered there is a marked near side-far side asymmetry. The near-side field is generally weaker and less structured than the far-side field. The strongest intrinsic lunar magnetic field detected is between the craters Van de Graaff and Aitken, centered at 20°S and 172°E. The variation in field strength with altitude for this feature suggests that its scale size is on the order of 80 km. A magnetization contrast between this region and its surroundings of the order of 6 × 10−5 emu-cm−3 is obtained assuming a 10-km thick slab. Preliminary Apollo 16 magnetometer data at extremely low altitude (0 to 10 km) show a very structured magnetic field with field strengths up to 56γ.

Large compressions in the magnetic field magnitude, just above the lunar limb regions, are occasionally detected when the Moon is in the solar wind. The occurrence of limb compressions is strongly dependent on the selenographic coordinates of the lunar region on the solar wind terminator beneath the orbit of the sub-satellite. The discovery of remanent magnetization of varying strength over much of the lunar surface and its correlation with limb compression source regions supports the hypothesis that limb compressions are due to the deflection of the solar wind by regions of strong magnetization at the lunar limbs. If this hypothesis is correct, then the map of lunar regions associated with compressions indicates that the northerly equatorial region on the far side is less strongly magnetized than the southerly equatorial region on the far side.

Keywords

Solar Wind Remanent Magnetization Equatorial Region Lunar Surface Limb Region 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Adler, I., Trombka, J., Gerard, J., Lowman, P., Schmadebeck, R., Blougett, H., Eller, E., Yin, L., Lamothe, R., Gorenstein, P., and Bjorkholm, P.: 1972,Science 175, 436–440.Google Scholar
  2. Arnold, J. R., Trombka, J., Peterson, L. E., Reedy, R. C., and Metzger, A. E.: 1972, to appear inSpace Research XIII. Google Scholar
  3. Barnes, A. P., Cassen, J. D., Mihalov, S. D., and Eviator, A.: 1971,Science 172, 716–718.Google Scholar
  4. Criswell, D. R.: 1972, ‘Photoelectrons and Solar Wind/Lunar Limb Interaction’, Preprint, submitted toMoon. Google Scholar
  5. Colburn, D. S., Mihalov, J. D., and Sonett, C. P.: 1971,J. Geophys. Res. 76, 2940.Google Scholar
  6. Coleman, P. J., Jr., Lichtenstein, B. R., Russell, C. T., Sharp, L. R., and Schubert, G.: 1972a, inProceedings of the Third Lunar Science Conference 3, MIT Press, Cambridge, Mass., pp. 2271–2286.Google Scholar
  7. Coleman, P. J., Jr., Russell, C. T., Sharp, L. R., and Schubert, G.: 1972b, ‘Preliminary Mapping of the Lunar Magnetic Field’,Phys. Earth Planet. Interiors, in press.Google Scholar
  8. Coleman, P. J., Jr., Schubert, G., Russell, C. T., and Sharp, L. R.: 1971, ‘The Particles and Fields Subsatellite Magnetometer Experiment’, inThe Apollo 15 Preliminary Science Report, NASA SP-289.Google Scholar
  9. Doell, R. R., Grommé, C. S., Thorpe, A. N., and Senftle, F. E.: 1970,Science 167, 695.Google Scholar
  10. Dyal, P., Parkin, C. W., and Sonett, C. P.: 1970,Science 169, 762.Google Scholar
  11. Dyal, P., Parkin, C. W., Sonett, C. P., DuBois, R. L., and Simmons, G.: 1971, ‘Lunar Portable Magnetometer’,Apollo 14 Preliminary Science Report, NASA SP-272.Google Scholar
  12. Dyal, P.: 1972, Private Communication.Google Scholar
  13. Gose, W. A., Strangway, D. W., and Pearce, G. W.: 1972, ‘A Determination of the Intensity of the Ancient Lunar Magnetic Field’,Moon, in press.Google Scholar
  14. Hartmann, W. K., and Wood, C. A.: 1971,Moon 3, pp. 3–78.Google Scholar
  15. Helsley, C. E.: 1971,Proc. Second Lunar Science Conference 3, MIT Press, Cambridge, pp. 2485–2490.Google Scholar
  16. Hosain, L.: 1972, ‘40AR-30AR Age of Apollo 15 Samples’, Abstract,Geological Soc. Am., Annual Meeting.Google Scholar
  17. Levy, E. H.: 1972,Science 178, 52.Google Scholar
  18. Milton, D. J., Barlow, B. C., Brett, R., Brown, A. R., Gilkson, A. Y., Manwaring, E. A., Moss, F. J., Sedmik, E. C., Van Son, J., and Young, G. A.: 1972,Science 175, 1199.Google Scholar
  19. Nagata, T., Fisher, R. M., and Schwerer, F. C.: 1972,Moon 4, 160.Google Scholar
  20. Ness, N. F., Behannon, K. W., Taylor, H. E., and Whang, Y. C.: 1968,J. Geophys. Res. 73, 3421.Google Scholar
  21. Runcorn, S. K., Collinson, D. W., O'Reilley, W., Stephenson, A., Greenwood, N. N., and Battey, M. H.: 1970,Science 167, 697.Google Scholar
  22. Siscoe, G. L., Lyon, E. F., Binsack, J. H., and Bridge, H. S.: 1969,J. Geophys. Res. 74, 59.Google Scholar
  23. Sonett, C. P. and Mihalov, J. D.: 1972,J. Geophys. Res. 77, 688.Google Scholar
  24. Strangway, D. W., Larson, E. E., and Pearce, G. W.: 1970,Science 167, 691.Google Scholar
  25. Urey, H. G.: 1971, Personal Communication.Google Scholar
  26. Whang, Y. C.: 1970,Solar Phys. 14, 489.Google Scholar

Copyright information

© D. Reidel Publishing Company 1973

Authors and Affiliations

  • L. R. Sharp
    • 1
  • P. J. ColemanJr.
    • 1
  • B. R. Lichtenstein
    • 1
  • C. T. Russell
    • 2
  • G. Schubert
    • 3
  1. 1.Dept. of Planetary and Space Science and Institute of Geophysics and Planetary PhysicsUniv. of CaliforniaLos AngelesUSA
  2. 2.Institute of Geophysics and Planetary PhysicsUniv. of CaliforniaLos AngelesUSA
  3. 3.Dept. of Planetary and Space ScienceUniv. of CaliforniaLos AngelesUSA

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