Dark Hole

• by CherylBrist

  Looks like a big hole in this picture.

  Posted October 18, 2013 2:51 AM

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

  It does. We want you to mark that dark patch with the blotch tool. That blotch is a deposit of dust and dirt. It is 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 think that if there is wind when the geyser deposits the material that it produces dark fans which you may have seen in other images and these dark blotches when there is little or no wind to blow the particles. We want you to mark these blotches and fans with the blotch and fan tool respectively. You can learn more about what these features are here and here.
  Cheers,
  ~Meg

  Posted October 18, 2013 7:41 AM