First MESSENGER orbital observations of Mercury's librations

  title={First MESSENGER orbital observations of Mercury's librations},
  author={Alexander Stark and Jürgen Oberst and Frank Preusker and Stanton J. Peale and Jean-Luc Margot and Roger J. Phillips and Gregory A. Neumann and David E. Smith and Maria T. Zuber and Sean C. Solomon},
  journal={Geophysical Research Letters},
  pages={7881 - 7889}
We have coregistered laser altimeter profiles from 3 years of MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) orbital observations with stereo digital terrain models to infer the rotation parameters for the planet Mercury. In particular, we provide the first observations of Mercury's librations from orbit. We have also confirmed available estimates for the orientation of the spin axis and the mean rotation rate of the planet. We find a large libration amplitude of 38.9… 

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