In this study, a spherical projectile vertical impact into a granular bed was numerically investigated with 3D Discrete Element Method (DEM) and validated with experiments. We vary the impact velocity (0.9-3.6 m/s) and size of particles in the bed (1-3 mm) and study the changes in ejecta velocity distribution for different impacts. We find good agreement for the total ejecta mass and for the velocity distribution of the ejecta between simulations and experiments, validating the numerical model and method for predicting the outcomes of low-velocity impacts into granular media. In addition, we analyzed the influences of granular bed size, solid volume fraction and particle density using the DEM and present the results of these simulations that could not readily be reproduced experimentally. The experimentally validated DEM thus enables exploration of parameter spaces that are impractical for experimental study. (C) 2015 Elsevier B.V. All rights reserved.