Impacted waves in granular media: A laboratory scale asteroids experiment

Asteroids and small bodies of the Solar System can be considered as agglomerates of irregular boulders, therefore cataloged as granular media. Ejections of particles and dust, resulting in a cometary-type plume, can result from impacts on their surface generating waves within these bodies and potentially causing modifications in the rocks distribution. Since no asteroid seismicity data are available, we propose a laboratory scale experiment of impact-induced seismic waves in granular media. Our study focuses on the influence of static compression mimicking pressure variations induced by self-gravity on the asteroid interior. A cubic box (50 x50 x50 cm) filled with different natural and artificial granular matter is impacted with low velocity projectiles (40 to 200 m/s). An array of accelerometers records the resulting wavefield while the box is compressed to understand its dependence with the monitored internal pressure. This study is relevant to understand how asteroids reacts to kinetic energy, as is will be tested at real scale during the Asteroid Impact and Deflection Assessment mission (2022).