Data Set Overview : This collection of asteroid masses and densities has been compiled from the published literature by Jim Baer, Steve Chesley, and Dan Britt. It also includes asteroid size and shape information, also collected from the published literature, to show the source of the tabulated bulk density. The version included in this data set is dated April 18, 2012. This data set supersedes the older PDS Asteroid Densities data set, EAR-A-5-DDR-ASTEROID-DENSITIES-V1.1.  In addition to the asteroid mass and density file, astmass12.tab, the file astmassrefs12.tab lists the full references of the published sources of the mass and size data. Only published values are included; a few unpublished values included in the original file have been removed.  In selecting size information for computing the bulk density, preference was given to the source with the most plausible greatest precision. In general, this yielded the following order of preference: - direct imagery (including adaptive optics) - radar - occultation - light curves - radiometric (especially SIMPS).  In addition to asteroids, entries for the Pluto/Charon/Nix/Hydra system are included. For comet masses, see the data set Properties of Comet Nuclei, EAR-C-COMPIL-5-COMET-NUC-PROPERTIES-V1.0.  Since the cited publication Standish (2001) is of limited availability, it has been provided in the document directory of this data set with permission from the author.  Standish, E. M., Suggested GM values for Ceres, Pallas, and Vesta, JPL Interoffice Memorandum 312.F-01-006, April 11, 2001. [Standish2001]  Modification History :  This data set was first archived in 2009 and has been updated since by adding additional asteroid masses that have been published since the previous update. The number of asteroid masses given in each version are  V1.0 - 151 V2.0 - 222 V3.0 - 248

Confidence Level Overview : These data have been compiled from various published sources. See the original papers for information about the confidence level of the values reported. A more frequently updated version of the compilation is available on-line at http://home.earthlink.net/~jimbaer1/astmass.htm.