Albedo measurements on meteorite particles

Abstract

We have measured single-particle albedos for several chondrite and achondrite meteorites and for carbonaceous material. We have introduced a new, relative method for measuring the albedo, including a new method for evaluating the particle cross-section. We determined albedos of 0.50±0.25 for ordinary chondrite, 0.15±0.02 for C2 carbonaceous chondrite, 0.64±0.13 for achondritic shergottite, 0.33±0.14 for enstatite chondrite meteorites, and 0.21±0.03 for carbon particles. Making use of the measured single-particle albedos, we have predicted geometric albedos for atmosphereless solar system bodies covered with regoliths of such particles. The geometric albedos are consistent with the values derived for C- and S-type asteroids in earlier works. However, for enstatite chondrite, the geometric albedo is much lower than that accepted for E-type asteroids. The predicted geometric albedos are 0.04–0.07 for C2 chondritic material and 0.13–0.24 for chondritic material. These ranges describe the usually accepted values for C- and S-type asteroids. Our results put important constraints on the radiative transfer models for the regoliths of asteroids and comets.