THE ASTRONOMICAL JOURNAL    VOLUME 112, NUMBER 5, PAGE 2319       NOVEMBER 1996

                   PROSPECTS FOR DETERMINING ASTEROID MASSES

                   JAMES L. HILTON AND P. KENNETH SEIDELMANN

  U.S. Naval Observatory, 3450 Massachusetts Avenue, NW, Washington, DC 20392
                    Electronic mail: hil@ham.usno.navy.mil

                                  JAY MIDDOUR

        Naval Research Laboratory, Code 8103, 4555 Overlook Avenue, SW,
                             Washington, DC 20375


                                   ABSTRACT

    The orbits of 4583 main belt asteroids are integrated orbits for 57
    years and searched for asteroid-asteroid encounters from which it may
    be possible to determine the masses of 23 of the largest asteroids
    (diameter >= 200 km) and 11 smaller asteroids.  The search is conducted
    using a scattering formula which serves as a useful filter for
    identifying encounters that can lead to a mass determination.  A total
    of 460 such encounters were found.  The ten most useful of these
    encounters are examined in detail.  The results show that, to make a
    reliable mass determination, the mean distance of the perturbed
    asteroid must be known to within a few times 10^-8 AU.  An observing
    program targeting the asteroids listed here would have a substantial
    impact on our knowledge of asteroid masses and densities.