#crazy-paving

#crazy-paving almost hexagonal polygons, surely the crazier the creak the more movement implied

Posted January 17, 2013 9:11 AM

That's a great way of putting it - even if I don't know what it means 😃 Hi There.

These are really great objects and they interest me a great deal. Like most people, I've got my own ideas about them. But I'm always keen to hear the ideas of others...

Posted January 18, 2013 12:28 AM

by eagiles

i am always one to hear an idea no matter how crazy they might be, is that not the point of discussion boards

Posted January 18, 2013 9:45 AM

by Kitharode moderator

OK then ... I've got an idea.

I'm happy with the 'formation of spiders' theory ( http://planetfour.org/#/about ) and I can see how they carve into the surface. Season by season the spiders will 'grow' and spread along the landscape.

What I don't know much about, but is surely important here, are the details of why certain 'materials' try to form hexagons/polygons/crazy paving. Salt plains, ice structures, mud in the bottom of a dry reservoir during drought, they all do it. Fortunately these details aren't important here.

For images like the one above I put the two things together (with an ice layer on top). Vents make spiders, spiders grow and 'hold hands', spider chains form crazy-paving because they follow the 'natural outline' of the hexagonal(ish) slabs formed by 'the natural tendencies of that type of stuff'. (Forgive the physics-less language).

My idea is that if I knew enough about the properties of ice, I'd be able to predict the formation of spider chains, or, conversely, if I looked at a pattern of spiders I'd know what type of ice cover was coming next season. If that were the case then I think that would be very cool indeed - as ice tends to be 😃

Posted January 19, 2013 1:22 AM

by eagiles

wow! what i don't understand is the term carved, they look more like cracks spreading from a weak as does glass/laminated or water ice, but this kind of pattern seems strange they are split from the tip very wide in a short distance, is there different acting a different times?. why am i thinking wave action it affect both polar ice on earth in similar ways

Posted January 19, 2013 7:36 AM

by Kitharode moderator

This is how I understand the carving to work. The surface of Mars is rock, often fairly smooth but probably always a bit dusty. A lot of the surface is very dusty indeed. It all gets covered in ice. Then, as explained on the About Page, gas forms under the ice and eventually blows a vent through the ice thats covering it. The plumes of gas and dust that escape through the vent make blobs and fans (if the wind is blowing).

Now, this explosive event sucks, and drags, and rips the dust out from under the ice, and this is what erodes the surface rock underneath (a bit like sandblasting gone wrong) and carves out a depression, as well as leaving more dust behind for the next explosion.

Later on in the martian season, the ice is gone but the carving remains. The cycle begins again. Season by season the surface becomes more scarred, until the carved out channels form into recognisable spiders. Some spiders really do look like spiders - we couldn't call them anything else really, could we?

But there's a lot going on to be sure. In your picture you've got what I call 'chain' spiders, and these chains make 'grid' or 'net' spiders, I think they do this because of the area they are in and the type of ice that covers them, but I'm not totally clear on that.

Posted January 19, 2013 10:09 AM