In these craters, virtually all the material was compacted, not ejected. This inspired the idea, Housen said, that perhaps the same kind of collapse might occur with impact craters on Mathilde if it really is very porous. Spinning the centrifuge to produce an artificial gravity 500 times that of Earth, the team shot small nylon projectiles at a target material that had the same density as Mathilde. You want to reproduce the weight of material that is being excavated on Mathilde. Boosting the gravity makes a small amount of material behave like it has much larger mass.
People test the aerodynamics of how airplanes work by making very small scale models.
The craters do indeed form without ejecta blankets. The holes on Mathilde appear to have been formed right next to one another, without affecting each other at all. Joe Veverka, who leads the imaging team for the NEAR spacecraft, said this kind of impact modeling is needed to explain Mathilde's curious craters. People have suggested that a very porous body might be able to dampen the shock of impact so that one crater might form next to another without causing major landslides, Veverka said. This explanation has never been tested with experimentation, however.