The shape of an impact crater isn't just about speed; a spinning projectile can 'migrate' underground to create tadpole-shaped holes.
March 31, 2026
Original Paper
Cratering by the oblique impact of a spinning projectile
arXiv · 2603.27746
The Takeaway
By simulating spinning objects hitting sand, researchers found that rotation can cause a projectile to travel large horizontal distances after impact or even bounce back out. This explains why some craters in nature have bizarre, asymmetrical shapes that don't match standard impact models.
From the abstract
We investigate the roles of spin and packing fraction on the dynamics of cratering when a solid projectile impacts a granular bed at different incident angles. For that, we carried out DEM (discrete element method) computations in which we varied the magnitude and direction of the projectile spin, the impact velocity, the bed packing fraction, and the incident angle. For a given incident velocity, we found that the projectile can rebound for small angles, or be completely or partially buried for