  The interactions of solid objects with granular media is countered by a
resistance force that stems from frictional forces between the grains and the
media's resistance to inertia imposed by the intruder. Earlier theories of
granular intrusion have suggested an additive contribution of these two
families of forces and had tremendous success in predicting resistive forces on
arbitrary shaped objects. However, it remains unclear how these forces are
influenced by gravitational conditions. We examine the role of gravity on
surface impact behavior into cohesionless granular media using hundreds of
soft-sphere discrete element simulations, we demonstrate that the outcome of
impacts remain qualitatively similar under varying gravitational conditions if
initial velocities are scaled with the Froude number, suggesting an underlying
law. Using theoretical arguments, we provide reasoning for the observed
universality and show that there is a hidden dependency in resistive forces
into granular media on Froude number. Following the theoretical framework, we
show that Froude number scaling precisely collapses impact trajectories across
gravitational conditions, setting the foundation for explorations in granular
behavior beyond Earth.
