Planet Four Talk

cirlcular ridge

  • aj2k08yahoo.co.uk by aj2k08yahoo.co.uk

    towards bottom right, a few different #fans coming off curved ridge

    Posted

  • Skylobby by Skylobby

    I agree ... I see about 10 curved sheets that overlap from which these eruptions seem to come from ... mmm interesting stuff - is there anyway to expand the picture and see a bigger picture - do you think ?

    Posted

  • michaelaye by michaelaye scientist

    these are what we call ice crack fans. The whole ground is covered here with a pretty translucent sheet of ice, and where it cracks, the pressurized gas from underneath breaks through and drags dust from underneath to the surface.
    "If the ice is translucent, why doesn't it look dark all the time then?" I hear you say. 😉
    The CO2 is extremely bright and these dark fans are in reality actually not that dark, the contrast comes from automatic stretching in the product production pipelines. Think about ilke this: In a polar area, with everything covered in ice, anything that's not ice, totally sticks out. And the rest of the uncovered CO2 ice is just very bright, that's why we can not see the dark ground underneath.
    Notice also that we call the ice translucent, in contrast to transparent. The difference is that transparency enables to identify structures behind the medium, like glass, and translucency is a 'softer' criterium, only demanding that some light gets through, but it totally could be scattered around and structures washed out in the process.

    BTW, if you look closely, lower middle, and the rows of fans behind the ones you identified is most likely as well a crack-based fan. It's when they line up like that without seeing 'spider-like' shapes underneath, that these fans are most likely stem from simple cracks in the ice. Simple idea, but still so super-weird, that it has not been observed on Earth, to my knowledge.

    Cheers all!
    Michael

    Posted