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Giant Spiders on Mars!

Eek, spiders! All right, so it’s not actually little green arachnids we’re talking about here, but they are definitely spidery features. Called araneiform terrain, these clusters of radially-branching cracks in Mars’ south polar surface are the result of the progressing spring season, when warmer temperatures thaw subsurface CO2 ice.

As dry ice below the surface warms it can sublimate rapidly and burst through the frozen ground above, creating long cracks. If the material below is dark it can be carried upwards by the escaping gas, staining the surface.

Each dark splotch is around 100 meters wide.

This image was acquired by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter on September 26, from a distance of 262 km (163.8 miles). See the full-size scan here, and check out more recent HiRISE images in the November PDS release here.

Credit: NASA/JPL/University of Arizona


A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

Comments on this entry are closed.

  • Aqua4U November 16, 2012, 5:32 PM

    “…staining the surface…If the material below is dark” or blowing away the accumulated dust? Probably a combination of both? I wonder how stable the surface around these areas are.. i.e. not good for walking across? What is the resolution of this imagery – how big are the ‘spiders’?

    • krenshala November 16, 2012, 7:02 PM

      Well, if you know the angular resolution of the camera, then you just need to figure out what width that is at a 262 km distance. Then divide that number of meters by 512 pixels (the width of the full-size scan linked to in the last para of the article) to get your meters per pixel resolution.

    • Jason Major November 16, 2012, 7:44 PM

      This gives you an idea of scale. Each “spider” is about 100 meters across. http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/ESP/ORB_028900_028999/ESP_028910_0985/ESP_028910_0985_MRGB.abrowse.jpg

      • Aqua4U November 16, 2012, 9:10 PM

        Thanks Jason.. very interesting. Mars sure is a strange place, Eh? Some day, I hope someone gets a chance to investigate those features up close!

  • lcrowell November 16, 2012, 6:51 PM

    Next up, Ziggy Stardust!


    • Jason Major November 16, 2012, 7:39 PM
      • lcrowell November 17, 2012, 1:51 PM

        That song is one of my all time favorites. I ended up listening to some Bowie tunes yesterday that I had not heard in a while.


        • Aqua4U November 17, 2012, 5:30 PM

          Yeah! Where is that guy? Lessee.. Mick is in his 70’s now, Bowie his 60’s? Tell you what…. if they keep rockin, so will I!

          • Jeffrey Scott Boerst November 17, 2012, 6:48 PM

            Good luck with that! As opposed to you, they’re all vampires! lol!

          • Aqua4U November 18, 2012, 5:49 PM

            Vampires? The recent fascination on the boob, cinema and web concerning ‘vampires’, is an interesting social phenom(?) but hardly worth more than a passing glance for me…

          • Jeffrey Scott Boerst November 18, 2012, 11:38 PM

            It was meant more as a quip per said rockers and their ilk’s odd shared palour of morbidity as if they were being kept alive (as Keith Richards is) by transfusing themselves with new blood now and again.

          • Muffie 1801 November 17, 2012, 11:32 PM

            Unfortunately, Mick Ronson died on April 29, 1993 after being diagnosed with terminal liver cancer.

  • Kevin Frushour November 16, 2012, 7:20 PM


  • Tim Amato November 17, 2012, 1:10 AM

    Sombody step on them!

  • Jeffrey Scott Boerst November 17, 2012, 5:57 PM

    Nice! I’m a HiView junky (when it doesn’t drop the data or crash) and I missed this mother image! Gonna go add more pics to my wallpaper slideshow folder now!