Photometric modeling of ejecta for evaluating defensive Kinetic impacts on asteroids

Kinetic impact is the most practical planetary-defense technique, with momentum-transfer efficiency central to deflection design. We present a Monte Carlo photometric framework that couples ejecta sampling, dynamical evolution, and image synthesis to compare directly with HST, LICIACube, ground-based and Lucy observations of the DART impact. Decomposing ejecta into (1) a high-velocity (~1600 m/s) plume exhibiting Na/K resonance, (2) a low-velocity (~1 m/s) conical component shaped by binary gravity and solar radiation pressure, and (3) meter-scale boulders, we quantify each component’s mass and momentum. Fitting photometric decay curves and morphological evolution yields size–velocity distributions and, via scaling laws, estimates of Dimorphos’ bulk density, cratering parameters, and cohesive strength that agree with dynamical constraints. Photometric ejecta modeling therefore provides a robust route to constrain momentum enhancement and target properties, improving predictive capability for kinetic-deflection missions.