Thread: What causes Hexagonal Craters?

Originally Posted by The Cusp

That determines it's specific fractal shape, but it's general shape is always 6 sided in a perfect hexagon.

Actually no, the "fractal" (not fractal) shape of a snowflake is due to "branching instability" The hexagon happens because that is how water molecules bond together.



Read more about it here.

Other molecules form hexagonal crystals.

Other molecules form other crystal patterns

If you'll notice, there are many craters that appear to be almost square, and others almost look like diamonds. This would be representative of some of the other crystal systems (cubic, rhombohedral, etc..).

I found this study that says that the polygonal shape is dependent on where the impact hits in relation to surface fractures (plates).

The origin of polygonal craters: A fractured
target material is a pre-requisite for the formation of
polygonal craters. Polygonal simple craters result when
the excavation of the crater progresses more easily
along a fracture (or some other plane of weakness)
than in other directions [4]. This typically leads to a
squarish outline, with crater rims making
approximately an angle of 45° with the fracture
directions [4,5]. However, experiments have shown
that two perpendicular fracture directions can also lead
to three rim orientations, i.e. a hexagonal crater [6].
Therefore the information gained from the study of
small polygonal crater rims can not be unambiguously
transferred to regional fracture directions.
Polygonal complex craters are the result of
slumping in the modification stage of the cratering
process: the collapse of the rim takes place along some
plane of weakness in the target [4]. Thus, the dominant
fracture directions in the area can be directly measured
from the orientations of the straight rim segments in
complex polygonal craters.