Granular eruptions

Researchers at the University of Twente in the Netherlands have created an experiment that beautifully demonstrates how sand can exhibit liquid-like properties. These photos are stills from a video the scientists recorded at 1,000 frames-per-second of a marble-size steel ball dropping onto loose, fine sand. The surreal footage may aid geophysicists in understanding what happens when an asteroid smashes into a planet.

"According to Shoemaker, the 'impact of solid bodies is the most fundamental process that has taken place on the terrestrial planets,' as they shape the surfaces of all solar system bodies. A lot of information on this process has been extracted from remote observations of impact craters on planetary surfaces. However, the nature of the geophysical impact events is that they are non-reproducible. Moreover, their scale is enormous and direct observations are not possible. Therefore, we choose an alternate and of course downscaled experimental approach in order to guarantee reproducible results." Link