Pre-encounter Predictions of DART Impact Ejecta Behavior and Observability

We overview various efforts within the DART Investigation Team's Ejecta Working Group to predict thecharacteristics, quantity, dynamical behavior, and observability of DART impact ejecta. We discuss variousmethodologies for simulation of the impact/cratering process with their advantages and drawbacks in relation toinitializing ejecta for subsequent dynamical propagation through and away from the Didymos system. We discussthe most relevant forces acting on ejecta once decoupled from Dimorphos's surface and highlight various softwarepackages we have developed and used to dynamically simulate ejecta under the action of those forces. With someadditional software packages, we explore the influence of additional perturbing effects, such as interparticlecollisions within true N-body codes and nonspherical and rotating particles' interplay with solar radiation pressure.We find that early-timescale and close-proximity ejecta evolution is highly sensitive to some of these effects (e.g.,collisions) while relatively insensitive to other factors. We present a methodology for turning the time-evolvingsize- and spatially discretized number density field output from ejecta simulations into synthetic images formultiple platforms/cameras over wide-ranging vantage points and timescales. We present such simulated imagesand apply preliminary analyses to them for nominal and off-nominal cases bracketing realistic total mass of ejectaand ejecta cumulative size-frequency distribution slope. Our analyses foreshadow the information content we maybe able to extract from the actual images taken during and after the DART encounter by both LICIACube andEarth-vicinity telescopes.