Small impact cratering processes produce distinctive charcoal assemblages

Importance of Cratering Processes

The importance of impact processes on a planetary scale has been recognized only fairly recently, after it became evident that not only our Moon (FIG. 1), but all other bodies in the solar system with a solid surface are covered with meteorite impact craters (FIG. 2). Impact cratering is a highenergy event that occurs at more or less irregular intervals (although over long periods of time, an a...

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...

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...