Past Orientation of the Lunar Spin Axis

  title={Past Orientation of the Lunar Spin Axis},
  author={William Rankin. Ward},
  pages={377 - 379}
  • W. Ward
  • Published 1 August 1975
  • Physics, Geology
  • Science
The orientation of the lunar spin axis is traced from the early history of the earth-moon system to the present day. Tides raised on the earth by the moon have caused an expansion of the lunar orbit. Tides raised on the moon by the earth have de-spun the moon to synchronous rotation and driven its spin axis to a Cassini state—that is, in a coprecessing configuration, coplanar with the lunar orbit normal and the normal to the Laplacian plane (which is at present coincident with the normal to the… 

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