Planet Four Talk

What are those lines?

  • jaroslavp by jaroslavp

    What are those lines that go across the picture? Sometime it looks like they go above surface.
    http://www.imagehosting.cz/?v=mars01.jpg

    Posted

  • wassock by wassock moderator

    Hi there theese lines are collectively known as yardangs there is more about them in the blog http://blog.planetfour.org/2013/01/15/you-have-asked/

    Posted

  • jaroslavp by jaroslavp

    I was talking abou those hair like lines not about yardangs.

    Posted

  • Kitharode by Kitharode moderator in response to jaroslavp's comment.

    The 'hair lines' are still unexplained. There's lots of yardang info, hair lines, and images in amongst the discussion here: http://talk.planetfour.org/#/boards/BPF0000008/discussions/DPF0000cce

    No definitive answers though. Maybe you've found yourself a project, eh? 😛

    Posted

  • jaroslavp by jaroslavp

    I was lookin for picture of ice on google and i think that those hair lines could be somethink like this.
    http://image.yaymicro.com/rz_512x512/0/2bc/cracking-ice-2bc976.jpg

    Posted

  • wassock by wassock moderator in response to jaroslavp's comment.

    Think that what you've found there is more akin to this sort of stuff APF0001n14. To my eye the fine faint tracks are different, much bigger/longer and look more like paths in the desert seen from on high than cracks - they are all curves with no angles

    Posted

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

    I agree with wassock. The cracks in the image you show are polygonal and we do see polygonal cracks on Mars in the ice. Anya, a member of the Planet Four Science team, has written a paper (there's a paywall but you can read the abstract) on this very subject. And one such beautiful example in Planet Four images can be found at APF0000hdp

    Cheers,

    ~Meg

    Posted

  • Kitharode by Kitharode moderator in response to jaroslavp's comment.

    The hairlines do indeed 'go above the surface', but only above the surface of the lower, more eroded surface. Rarely, if ever, do they stand above the higher surface of the smooth lines of yardangs. The hairlines sometimes follow the edge of a depression, they often meander through the depressions, but the line is usually broken when it meets a yardang. This implies to me that the ridge of the hairline is at the same level as the yardangs suggesting, perhaps, that they belong to the same layered deposit.

    The HiRise image is centred on -85 degS and 67 degE in the area known as 'Giza'. It is within the area of the polar layered deposits which are, at this location, about 2km thick. There are many polygons on show there.

    Posted