CONTROLS ON ASTEROID POROSITY: REVIEW AND NEW DATA FOR S-COMPLEX ASTEROIDS

Understanding the properties of asteroids provides insight into the formation of the Solar System, and aids planning of space exploration and mining. However, the current asteroid database represents only 0.04% of small bodies in the Solar System. Previous work used this more limited dataset to archive the density and porosity of planetary objects in the Solar System, and evaluate general trends in asteroid properties. This study: 1) adds 40 datapoints to the current database, 2) re-evaluates 11 asteroids with unrealistic mass, density, and porosity, 3) evaluates previously proposed relationships between mass, density, porosity and orbital distance, and 4) proposes indirect estimation of porosity using asteroid estimated mass and density, spectral taxonomy, absolute magnitude, and albedo. A polynomial fit represents S‐complex asteroid mass (kg) vs. diameter (km) (n=30) with a correlation coefficient of 97% for asteroids with diameter from 13.44 to 225.89 km. C‐complex asteroids (n=67) have a more complicated taxonomy than S-complex asteroids making them more difficult to interpret; initial results suggest mass, density, and porosity can be indirectly determined for 231 asteroids using similar curve fit. Previous studies noted an average porosity of ~20%, and a correlation between orbital distance and asteroid porosity. Our estimated porosities are consistent with the previously observed average of ~20%, but we found no relationship between asteroid semi‐major axis and any asteroid physical property (i.e., mass, density or porosity). In conclusion, our expanded database supports the indirect relationship between asteroid density and porosity, not orbital distance. Further, we suggest that asteroid porosity may be indirectly determined using estimated mass and density, spectral taxonomy, absolute magnitude, and albedo.