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E. M. Standish (JPL)
The fitting of planetary ephemerides to precise astronomical measurements provides one of the best means of determining certain astronomical parameters. However, this process is limited by uncertainties in the values of the masses of the many asteroids which affect the planetary motions. Similar to the study by Standish and Fienga (2002) which illustrated the limits on planetary orbital accuracies, this study illustrates the limits on the values of relevant model parameters determined in the adjustments - values such as the planetary masses, the asteroid masses and densities, the rotational parameters of Mars, the relativity parameters, beta and gamma, the time-change of the gravitational constant, the earth-moon mass ratio, the length of the astronomical unit, etc.; The results are shown as histograms, showing the scatter and offsets in the various determinations arising from a monte carlo process using different random errors in the asteroid masses.
Acknowledgment. The work described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
The author(s) of this abstract have provided an email address for comments about the abstract: ems@smyles.jpl.nasa.gov
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Bulletin of the American Astronomical Society, 34, #3
© 2002. The American Astronomical Society.