Geometric Albedo Curves for Impact-Plume Particles from Sub-micron to cm Scale

The attached .csv file lists geometric albedo models for particles in the DART impact plume, as described in the study by Glenar et al., “The importance of Particle Light Scattering Properties in Optical Studies of Impact Ejecta”, submitted to a Special Issue of Advances in Astronomy, “Progress in Planetary Defense”, July 23, 2025.These models were assembled from a collection of discrete dipole (DDA) calculations, laboratory phase matrix measurements and OSIRIS-REx observations of natural particles released from Bennu. Models are listed in five broad size categories: “Sub_micron”, “Micron_Size”, “Sub_mm”, “mm_Grain”, “cm_Size”, along with upper/lower limits (designated “H” and “L”) that represent uncertainties.Representative radii for the categories, to be used as interpolation knots, are: 0.5 microns, 4.4 microns, 125 microns, 4.8 mm and 2 cm, respectively. For purposes of numerical integration, geometric albedo as a function of grain size (a) and phase angle (a) can be obtained from these lists using log(a)-linear(a) interpolation.Limitations:1. To the extent possible, this set of albedo models has been tailored to represent ejecta from the Didymos-Dimorphos system, by adjusting albedos, optical constants and scattering parameters where warranted. These results have not been validated for use in other studies (e.g, analysis of lofted dust in lunar surface exploration).2. This set of models is considered valid over the domain of particle sizes in the DART plume (≈1 micron to > 2 cm). Albedo curves for particle radii >2 cm should be assigned the a=2 cm values.3. Phase angle coverage extends from 0 deg to at least 140°. Beyond 140° (the forward scattering domain) it has not been validated, especially in directions influenced by diffraction, which depend on size distribution.4. These geometric albedo values are broadly applicable to visible wavelengths, but should otherwise be considered gray, because of the sporadic nature of the wavelengths in the data sources used to construct the models.