Planet Four Talk

Mini craters?

  • JellyMonster by JellyMonster

    What has caused this abundance of mini craters? I've no idea what the hairline crack effects are either? The image has been spun 180.

    ![Pebble-dash] (https://dl.dropbox.com/s/vzh3lc43dpmc3cn/R-50e73cfa5e2ed21240000ee5.jpg)

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  • Kitharode by Kitharode moderator

    Never seen this sort of stuff before. Looks like great fun. Go on then, what's your name for this sort of area? You found it!!

    First impression only, I don't know what they are, but I'll use 'craters' for now. The colour of the image is not constant, there are darker/lighter areas. I get an impression of smaller craters grouping together, ditto the larger. With that in mind, can you see two fairly large 'circular' groupings, lighter in colour than their surroundings? One is near the top of the image, the other hangs from centre of image, they would both roughly fill a quarter of the image.

    If you do, you'll see a darker patch to the left of the centre circle and if you flick between this patch and the top circle, hopefully you'll see the larger/smaller effect. This could easily be nothing more than an effect, there's bound to be frost and dust in there somewhere, but I don't think that's the cause of the circular effect. For me, a good chance there's more to it than just a visual effect.

    Good find. And the area is called what ... ?

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  • JellyMonster by JellyMonster

    Others found it before me... I stole it and made up a post 😃

    Did you ever do metalwork at school, perhaps shaping a piece of metal into a bowl by tapping lightly with a small hammer... what was this process called?

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  • Kitharode by Kitharode moderator

    OOPS !! Should have said that my description was based on original image, not on JM's rotated image.

    Didn't do it, but I know precisely what you mean about the metalwork effect. Don't know name of process, sorry. But it's a great analogy to me because they're 'obviously' mini-craters, but I know of no way to produce this sort of thing by meteor impacts. Either I'm going to be told of a new way, or these aren't craters. Yet another hmmm....

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  • Kitharode by Kitharode moderator

    ...Do we know where about's this is on Mars? Yes, there's the hairlines again. Weird. Often think they're following the line between the high crater edges then wham, straight through the middle of a crater or two. How does that work I ask myself.

    Dragged boulders have been mentioned before and you can see here why that's been suggested. Many craters line up nicely to give that effect when you're not zoomed in. Some definate 'beyond coincidence' alignments for me though and might I be right in thinking a lot of these have a hair running through them?

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  • JellyMonster by JellyMonster in response to Kitharode's comment.

    As you say, the 'hairlines' seem to go straight through anything in their path. Have a look at the image below (I've spun it and added a bit of colour). Are these the same markings?

    ![Hairlines] (https://dl.dropbox.com/s/ewd6yhh0ioogroy/R-50e745aa5e2ed21240005863.jpg)

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  • Kitharode by Kitharode moderator

    Not only a wizard, but a mindreader too. This image is gold dust to me JM.

    To me, this image represents something of a halfway point between the two types of yardang we're studying elsewhere and I couldn't have found a better example than this to join the two together. I'm convinced I'm getting close to telling a sensible story about how these yardangs relate to each other, by location and over time.

    We're definately in yardang terrain and to me the hair lines are the same as the others we've met. Different area, but thin continuous ridges is what I see. But there are spiders too - yeehaaaa. Thin spiders they may be, but they're enough to help me move along. You see the spiders?

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  • JellyMonster by JellyMonster in response to Kitharode's comment.

    You see the spiders?

    Er... not really. You must have x-ray vision! Are they more like super-thin? Anyway I'm glad the image is of use to you.

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  • Kitharode by Kitharode moderator

    Same thickness as the hairlines. Easy to confuse the two, but I know they're there. Image brill. Ta.

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  • JellyMonster by JellyMonster in response to Kitharode's comment.

    I think I do see em'... they're tiny!

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  • Kitharode by Kitharode moderator

    Please don't look at the link yet. Look back at your picture above. Look at the hair lines, an overall view. A few parallel-ish, a bit grid-like overall? Now imagine the image covered in ice, in springtime. Do we get this?

    http://planetfour.org/subjects/standard/50e73ec45e2ed21240001e08.jpg

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  • JellyMonster by JellyMonster

    Yes I follow. So the hairlines are definitely cracks then?

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  • Kitharode by Kitharode moderator

    Not neccesarily, I don't know yet. But it's good that you follow my point. Thing is I've got a good collection of linear venting like the above, as well as 'curved' linear venting, but leaving aside an odd idea I've never really been able to make sense of what's going on.

    But if you agree that the linear venting might well be associated in some way with the hairs, cracks or other wise, then that's a start. You'll have to tell me if you 'see' this association. Up to now I'd generally thought 'channel' (ice might be thinner) or 'cracks' in the ice cover (lets grust out). But might it be that the hairs (as ridges) are the trigger for this linear venting?

    To me that's an attractive, and not implausible, scenario here. What do you think?

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  • JellyMonster by JellyMonster

    What do you think?

    I think you should ask wassock 😃 (or AUricle)!... sounds plausible though.

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  • Kitharode by Kitharode moderator

    Hahaha, and you tell me "I'm no good at jokes" (remember?). Nice one. Wassock's bound to drop by sometime. The others are late!!

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  • wassock by wassock moderator

    I still don't buy them as cracks, still only seen them on the one type of terrain, and they have an 'organic' feel, not as angular as the obvious cracks. And there's bugger all venting from them. But I can't see them in the few summer images I've found.

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  • Kitharode by Kitharode moderator

    It's the hairs you don't buy as cracks. Yes?

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  • wassock by wassock moderator

    Hairs yup

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