Situated on the rim of an older, larger crater, Mena does not take on the typical bowl shape created by smaller impacts.

Instead, Mena is classified as a complex crater with a peak located inside the bowl-shaped cavity.

Before the impact that created Mena, the target material was not evenly distributed.

Thus, when the impactor struck, shock waves were not able to evenly propagate through the target material.

This, in turn, led to the regions of varying uplifted material inside the crater.