The MEMIN research unit: Experimental impact cratering

The Deep Impact oblique impact cratering experiment

The Deep Impact probe collided with 9P Tempel 1 at an angle of about 30◦ from the horizontal. This impact angle produced an evolving ejecta flow field very similar to much smaller scale oblique-impact experiments in porous particulate targets in the laboratory. Similar features and phenomena include a decoupled vapor/dust plume at the earliest times, a pronounced downrange bias of the ejecta, a...

Impact cratering and the Oort Cloud

We calculate the expected flux profile of comets into the planetary system from the Oort Cloud arising from Galactic tides and encounters with molecular clouds. We find that both periodic and sporadic bombardment episodes, with amplitudes an order of magnitude above background, occur on characteristic time-scales ∼25–35 Myr. Bombardment episodes occurring preferentially during spiral arm crossi...

Martian Impact Cratering and Martian Layered Sediments

Modeling of impact cratering in granular media

We simulate penetration of large projectiles into dry granular media using two-dimensional soft particle molecular dynamics. We systematically vary the physical parameters of the projectile (density, size, impact energy). Our results confirm the recently observed scaling of the crater depth with impact energy as observed by Uehara et al. (2003) and the effect of constant deceleration of the bal...

Projectile interactions in granular impact cratering.

We present evidence for the interactions between a ball and the container boundaries, as well as between two balls, that are mediated by the granular medium during impact cratering. The presence of the bottom boundary affects the final penetration depth only for low drop heights with shallow filling, in which case, surprisingly, the penetration becomes deeper. By contrast the presence of the si...