Johns Hopkins engineers have uncovered new details about how granular materials such as sand and rock behave under extreme impacts—findings that could someday help protect the Earth from dangerous asteroids.

"Our study shows that different parts of a material, and even different grains of sand, can behave in very different ways during the same impact event "

The researchers found that, in addition to other chemical reactions, the heat created by intense compression leads to the grains fracturing, melting, and re-solidifying.

The team observed that different metallic materials exhibit distinct ways of dissipating energy during high-speed impacts. Materials such as aluminum absorb energy by the formation of defects and plasticity, while brittle materials like soda lime glass dissipate energy by fracturing and fragmenting.

Quantifying 3D time-resolved kinematics and kinetics during rapid granular compaction, Part I: Quasistatic and dynamic deformation regimes

https://www.sciencedirect.com/science/article/abs/pii/S002250962400231X