What causes Hexagonal Craters?

I was just looking at the most spectacular color image of the moon, and I couldn't help but notice the sheer number of Hexagonal and Pentagonal shaped craters. They are mostly Hexagonal, but there are even a few octogons scattered here and there.

http://www.rc-astro.com/photo/id1018_big.html

The seem to be more evident in the older, more eroded craters. Anyone have any thoughts on what would cause that? Happens on every crater filled body we've photographed.

There is also a permanent hexagon on one of Saturn's poles
http://news.nationalgeographic.com/n...exagon_big.jpg

And Pentagon's have been photographed in the eyes of tornadoes
http://www.cyberspaceorbit.com/hurri...-pentagram.jpg

Perhaps the same force that shapes snowflakes? While every snow flake my be unique, every single one has a hexagonal shape.

It's a pretty obvious phenomenon, but I've yet to hear any good explanations for it.

I'm not seeing anything on the moon. You'll have to point it out for me.

It could just be one of those cases of "out of every 1,000 random crater/weather shapes, one looks geometric." The one really doesn't look like a pentagram but rather some random wisps of clouds. I mean, if you look at a hurricane for long enough, you're likely to see something that barely resembles a geometric pattern.

I don't see them in the craters either.

And BTW, that's a hurricane, not a tornado. lol

I'm with the other guys; the craters are not hexagons in a way that goes beyond confirmation bias.

Now, the entirely unrelated hexagonal cloud pattern on Saturn has to do with the relative rates of periodic feedback loops. Although the forces are completely different, a good example/analogy to this is Bode's Law. The distances of the planets from the sun follow a very simple pattern. And the reason for this is because the solar system formed chaotically, and ironically, chaos tends to produce beautiful and extreme examples of simplicity and order if you give it enough time.

You guys really don't see them? Like I said, it's especially in the more eroded craters. Start with the largest discoloration patches, and then look at the eroded craters.

I'll trace them out on a separate picture, but it's going to take time because there are so damn many of them. Probably hundreds! I really find it hard to believe you people can't see them!

Ok here I traced some of them out very quickly and clumsily. The shapes are actually more apparent without my scribbles on the original, but they just let you know where to look.

http://www.fotofap.com/files/454298_...on_color_1.jpg

There are WAY more than those few I indicated. Once you get used to seeing them, they are everywhere.

Look, 3 of us didn't see shit, so you're just seeing them because you want to see them. Confirmation bias.

The shape of snowflakes depends on the shape of water molecules and the way they fit together. Crystallization is a process of patterns building off of each other from the very small on up. Although I don't know that a similar process happens with craters, I do know that when a meteor collides with the moon or the Earth, or any much larger body, the force of the impact melts the area where it hits, and so it could cause a crystallization of the minerals as they cool and re-solidify.

p.s. I think the geometric shape of many of the craters is fairly obvious.

Here are the two that are most clear to me.
Above is the crater outlined and below is the original.
http://img.photobucket.com/albums/v5...ia/craters.jpg

Yeah, I don't see them either.

Plus, eroded craters? I'm pretty sure there's no atmosphere on the moon to erode them.

Because they are older, they probably came about when the moon had a liquid core. When a large object hit it it probably caused large splits in the crust which would spiderweb out. The craters would push out along these cracks causing flat sides.

Just a thought, I have no idea though.

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Originally Posted by Kushna Mufeed

Yeah, I don't see them either.

Plus, eroded craters? I'm pretty sure there's no atmosphere on the moon to erode them.

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The older craters seem to be more level, with less impact ridges. Whatever causes it, that's the general definition of geological erosion in that scenario. Sheesh!

You people must be half blind. Some craters are perfectly round, others ringed by straight lines. You're not even trying to find them.

http://www.fotofap.com/files/454298_...on_color_1.jpg

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Originally Posted by Xaqaria

The shape of snowflakes depends on the shape of water molecules and the way they fit together. Crystallization is a process of patterns building off of each other from the very small on up. Although I don't know that a similar process happens with craters, I do know that when a meteor collides with the moon or the Earth, or any much larger body, the force of the impact melts the area where it hits, and so it could cause a crystallization of the minerals as they cool and re-solidify.

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

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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.

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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.

http://www.its.caltech.edu/~atomic/s...celattice2.jpg

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).

Quote:

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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.

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Quote:

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Originally Posted by Xaqaria

Here are the two that are most clear to me.
Above is the crater outlined and below is the original.
http://img.photobucket.com/albums/v5...ia/craters.jpg

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Yeah, those look like random craters.

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Originally Posted by DNK

Yeah, those look like random craters.

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except

A) they don't

and...

B) I've already presented evidence that shows this is a common phenomenon.

You know what else looks like a hexagon? France! I smell a cover-up.

Quote:

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Originally Posted by Xaqaria

The shape of snowflakes depends on the shape of water molecules and the way they fit together. Crystallization is a process of patterns building off of each other from the very small on up. Although I don't know that a similar process happens with craters, I do know that when a meteor collides with the moon or the Earth, or any much larger body, the force of the impact melts the area where it hits, and so it could cause a crystallization of the minerals as they cool and re-solidify.

p.s. I think the geometric shape of many of the craters is fairly obvious.

Here are the two that are most clear to me.
Above is the crater outlined and below is the original.
http://img.photobucket.com/albums/v5...ia/craters.jpg

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lol wishful thinking. Those craters are pretty fucking round if you ask me. Maybe some rocks lay in such a way it seems a bit like neat little snowflakes. Then again, you can see fucking faces on Mars. Yeah. If you look long enough, you can probably find a crater that looks like elvis.

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The thing on saturn, that actually is a bit more a hexagonal or pentagonal: Nature sometimes can cause funny shapes. Some minerals even 'grow' in almost perfect cubes. Pretty awesome. Don't know why saturn has such awesome clouds, but I am sure it could be calculated why it happens in some how-gas-acts-bla simulator.

I see what you mean, though I have no clue as to why.

but yeah the thing on saturn is way cooler.

There are no hexagons on the moon. A hundred craters or so and a couple look like they have roughly straight edges..?

But the Saturn thing is cool. It's probably unexplained too, turbulence is one of the last mysteries of physics actually.

Quote:

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Originally Posted by Xei

But the Saturn thing is cool. It's probably unexplained too, turbulence is one of the last mysteries of physics actually.

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Unexplained insofar as they don't know if their very plausible explanation is Saturn's explanation. It has been shown that hexagonal patterns can be formed in spinning buckets of water, so that would suggest that it's just a resonance between Saturn's rotation and the prevailing wind.

Observing hexagon patterns either in water or on Saturn is not explaining them, is it?

Quote:

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Originally Posted by Xei

Observing hexagon patterns either in water or on Saturn is not explaining them, is it?

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I thought it was obvious from my wording that the polygonal patterns in buckets are very well explained by fluid dynamics.

They're not.

Quote:

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Originally Posted by Xei

They're not.

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You seem to have the denial thing down. Why don't you move on to the backing yourself up stage? Perhaps you'd like to start by refuting (with evidence) the source I linked to that gives an explanation for the fairly common phenomenon of craters forming polygonal shapes.

http://www.planetary.org/blog/article/00000927/
"This study is probably not directly applicable to Saturn."

This seems to be a very obscure area of fluid dynamics with unsurprisingly minimal research.

Quote:

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Perhaps you'd like to start by refuting (with evidence) the source I linked to that gives an explanation for the fairly common phenomenon of craters forming polygonal shapes.

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Well Googling seems to suggest that there are some smaller polygonal craters which have been observed on the moon, and it's suggested that these are the results of the local tectonics. But certainly its not a very important effect on the large scale, those highlighted ones don't look convincing on their own, let alone when taking into account the large number of other randomly shaped craters.

Quote:

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Originally Posted by Xaqaria

You seem to have the denial thing down. Why don't you move on to the backing yourself up stage? Perhaps you'd like to start by refuting (with evidence) the source I linked to that gives an explanation for the fairly common phenomenon of craters forming polygonal shapes.

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Seriously, what's there to refute? The craters aren't polygonal in any significant sense. What do you want me to do, draw a circle around them, because that's what you've done... (point: that isn't proof)

Neither moon crater is a proper, single crater. They both have been significantly disturbed by other impacts, which have significantly altered their outline. This is like trying to prove an optical illusion... there's no way. I (we) say there is a circular shape, you say otherwise. Leave it at that.

But a point should be made that this isn't proof of anything if there can be such a simple subjective difference. I think my argument is that tricks of the eye cause hexagonal craters (in most cases at least).

Necro this thread to post a possible explanation from the Harvard website: A new explanation for the hexagonal shape of lunar craters

"The possibility of impacts of large meteorites on the thin crust of the early moon accounting for the formation of the hexagonal lunar craters is discussed. Solidified basalts comprising a lunar crust of thickness 10 to 50 km characteristic of the earliest stage in lunar evolution are shown to have a large-scale hexagonal pillar structure, due to the effects of shrinkage. Results of experimental simulations of the propagation in this hexagonal pillar structure of the shock wave generated by the impact of a meteorite of diameter 10 km and mass 10 to the 15th kg on the lunar crust are then presented which demonstrate the pushing away from a central circular shock of pillars resting on a low-friction surface in a hexagonal pattern."

But I suppose Harvard is only seeing hexagons because they want to...

http://files.abovetopsecret.com/file...cf2c1daad5.jpg