Dark images can reveal all sorts of things

• by JellyMonster

  Dark images are sometimes ignored because they appear uninteresting at fist glance. Messing about with your monitors contrast/brightness settings helps but I don't recommend it. You are better off saving the image to disk first, then importing into an image editing program. Rotating it through 180° will help distinguish peaks from troughs. By altering the hightlight/shadow levels and perhaps a little sharpening you might be surprised at what you see.

  If you go to the HiRISE image (greyscale/non-map) the spiders seem to be dislocated - what causes this?

  ![APF000188s] (https://www.mediafire.com/convkey/6a5f/osf4gaw3a127zt86g.jpg)

  Posted February 5, 2014 9:45 AM

• by p.titchin in response to JellyMonster's comment.

  Great example Jelly, should really help people to understand the light orientation/ ridge or valley illusion. Nice boulders for my collection as well! 😃 Pete.

  Posted February 5, 2014 12:18 PM

• by JellyMonster

  Thanks for your comment Pete. Obviously, everyone out there will have a different monitor set-up, so it still maybe too dark for some? Did you look at the HiRISE image?

  Posted February 5, 2014 12:57 PM

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

  JM: You suggest a rotation of 90deg for the image. Do you mean 90? (I thought you did 180deg rotations). I've not seen the HiRise image yet - more later.

  Some of the objects in the top left corner of the image above might be useful in Angie60's study.

  Posted February 5, 2014 4:12 PM

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

  Finger Lake - Easy to see why it's an area of interest for the scientists.

  I'm not sure what you mean by 'dislocated' spiders. Can you say more?

  Posted February 5, 2014 4:22 PM

• by JellyMonster

  Kitharode, you're right it should be 180° and not 90 - good spot.

  It looks to me that the spider 'body' has flattened out leaving dislocated legs everywhere - see HiRISE (Greyscale non-map).

  Posted February 5, 2014 9:36 PM

• by p.titchin in response to JellyMonster's comment.

  Yes, I looked at the HiRISE, but like Kith, I was unsure what You meant by 'dislocated'. Now, Ive looked again, I think I see what you mean. The Finger Lake images often seem strange. I would like to see the underlying topography, but it adds to the mystery of the differences in spider form and evolution. Perhaps this is a stage in the evolution of a more organized 'spider network'. I'll see if I can find any more recent Finger Lake images. ~Pete

  Posted February 6, 2014 10:11 AM

• by Kitharode moderator

  'Dislocated legs' - yes, I get it. No answers I'm afraid.

  Can anybody remember if 2007 (the year of this image) was the year of the great dust storm, or was it 2009?

  Posted February 6, 2014 5:10 PM

• by mschwamb scientist, translator

  Hiya,

  The global dust storm was in 2007 between seasons 1 and 2 (http://blog.planetfour.org/2013/12/11/aftermath-of-a-global-dust-storm/)

  Cheers,

  ~Meg

  Posted February 8, 2014 3:53 PM