Planet Four Talk

Fabulous detail but not calssifiable with given classifications

  • bleighuk by bleighuk

    Looks like lots of "rivers".

    Posted

  • JellyMonster by JellyMonster

    Certainly different to what I have seen so far. Even rotating the image doesn't help in this instance!
    http://blog.planetfour.org/2013/01/16/if-it-looks-like-a-ridge-its-a-valley-1st-rule-of-mars/

    Posted

  • Kitharode by Kitharode moderator

    Don't know for sure, but it could be related to yardand terrain. I'm just beginning to realise that yardangs are not just tramlines. There's allsorts and I think this may be related. Don't take any of this as fact yet, but...

    'Layered deposits' seem to be needed to form yardang terrain and some of these are very old, but some are more recent. Some are more worn, others appear less so. You need strong winds and yardangs can be weirdly shaped. It seems that when the old layers were laid down the winds that gave them their tramlines blew in a different direction than the winds we have today on Mars.

    I get the feeling that some yardangs, in some areas, never got overlayed by new stuff so we see them as is. Other areas (guessing again) may have most recent stuff overlayed but this has been worn away to a 'patchy'/'hair lined'(?) type of terrain. However, before it gets to that stage it may be formed into more recognisable tramlines (following the direction of new wind) with evidence of the old layered deposits 'showing through'.

    My feeling is that spidering only happens in some areas of yardang terrain because the layering is there/not there or that the time is right for them to get a grip. Your spidering, I think, will eventually turn into a crowded field of mishapen Sphinxes with a network of pathways around and between them. I've read that some believe the Great Sphinx of Egypt is indeed an example of yardang so that's why I mention it.

    So some of the above is 'fact', some needs confirming, there's bound to my madness in there. Thing is that more you learn the less you know applies here, but I'm sure there's a history we can unravel for ourselves. Anyway, if yardang think layered deposits, changing winds, and long timescales. Far as I've got on that.

    Your title had me going there for a bit .. !!

    Posted

  • mschwamb by mschwamb scientist, translator in response to Kitharode's comment.

    These aren't yardangs. They are part of the channels carved in a similar manner to the spiders. Just in this case the channels are more interconnected rather than originating from a single point. I believe the nickname was "lace terrain" has been given to spider features that look like this. So these are still carved channels by the carbon dioxide gas trapped under the thawing ice sheet in the spring and winter. You can see some examples in this press release from a few years ago.

    Phase 2 of the project will be characterize the different types and frequency of these different types of spider channels.

    Cheers,
    ~Meg

    Posted

  • Kitharode by Kitharode moderator

    Thanks Meg. Not yardangs. Ah well, I can keep that in mind whilst I'm trying to find out what is/isn't yardang.

    I see the spiders 'holding hands' to form the lace terrain, but I'd wondered whether they were part of a process/evolution in yardang territory and only came into play when, for example, all the top layer had been swept clear so that 'spider regolith' became visible. I'm still unclear about what lives where on mars, and what comes in what order, and how long things take to do their stuff. But I'm getting there.

    I accept the image isn't yardangs, you know best (for now, hohoho). But is my picture of layers old and new, and winds that change, and some yardangs wearing down to something else, a good place to start for me. Maybe I should throw it all out and take a different approach and if so, what approach might that be? Leave here and take up gardening perhaps, or golf?

    Posted