Planet Four Talk

Shadows?

  • eugenius by eugenius

    These look like shadows to me. Are we supposed to assume that they are deposits, nevertheless?

    Posted

  • mschwamb by mschwamb scientist, translator

    Those are blotches that we want you to mark. The dark blotches and fans that you may see in the images are deposits of dust and dirt. They are produced by carbon dioxide geysers on the South pole of Mars which lofts the dust on to the top of the carbon dioxide ice sheet in the summer and fall in the Southern hemisphere. We want you to mark these with the blotch and fan tool. You can learn more about what these features are here and here.

    Cheers,

    ~Meg

    Posted

  • Kitharode by Kitharode moderator

    It might also be worth mentioning that sunlight is coming in from the lower right corner in these images. This puts the fans and blotches on the sunside of the bright lines.

    The bright lines are depressions carved into the surface so they don't cast a shadow on the surface. The channelling is easier to see in the long thin lines forming blocks. The sunlight falls on the up slope of the channel (on the left) with the down slope being in shadow.

    Great image. I've put it in my linear features collection. Thanks. 😃

    Posted