  Combining high-speed photography with laser profilometry, we study the
dynamics and the morphology of liquid-drop impact cratering in wet granular
media---a ubiquitous phenomenon relevant to many important geological,
agricultural, and industrial processes. By systematically investigating
important variables such as impact energy, the size of impinging drops and the
degree of liquid saturation in granular beds, we uncover a novel scaling for
the size of impact craters. We show that this scaling can be explained by
considering the balance between the inertia of impinging drops and the strength
of impacted surface. Such a theoretical understanding confirms that the unique
energy partition originally proposed for liquid-drop impact cratering in dry
granular media also applies for impact cratering in wet granular media.
Moreover, we demonstrate that compressive stresses, instead of shear stresses,
control granular impact cratering. Our study enriches the picture of generic
granular impact cratering and sheds light on the familiar phenomena of raindrop
impacts in granular media.
