NASA - National Aeronautics and Space Administration

+ Video of impact experiment (3 MB)
+ Higher resolution version (8 MB)

This video shows an impact experiment of a high-speed impact into a frozen comet-like material (dust, ice, window cleaner and Worchestershire sauce) over a highly porous target (garden perlite). The impact makes a small hole in the comet, simulating a strength-controlled crater, but a large crater grows below and peals back the surface crust like petals of a flower. The result is similar to a deeply buried explosion.

Credit: NASA