Planet Four Talk

Dust Storm?

  • wassock by wassock moderator

    This is another feature on the HiRise image used in the Double Craters Thread http://hirise.lpl.arizona.edu/PSP_009711_1640

    The capture is from the low res Greyscale image which shows whatever it is more distinctly than the high resolution JP2 image

    http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/PSP/ORB_009700_009799/PSP_009711_1640/PSP_009711_1640_RED.abrowse.jpg

    This is from the left side about a quarter of the way down

    enter image description here

    What I'm seeing is outlined below - the white outline is a shadow caused by the red column of dust/cloud and theres a more diffuse cloud of dust in yellow which is either the way the storm has moved or is the wind direction.

    The marking tool on HiRise gives the crater below/left/touching the red outlined bit as about 90 meters across

    Can anyone else see this the way I do?

    enter image description here

    Posted

  • Kitharode by Kitharode moderator

    Yes, I see the lighter patch above the central feature and the darker patch below moving right. The idea that the central feature might be a cloud/storm isn't clear to me, but you could be right. I've no idea what else it might be.

    I didn't know there was a HiRise marking tool. Where's that then?

    Posted

  • wassock by wassock moderator

    The marking was done on the cropped image using paint. The Hiveiw viewer has a tool which lets you measure things.

    The crux with the image is if the dark area is actually the shadow of the cloud, far as I can see it is in the right place compared with the other shadows

    Posted

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

    Fascinating thoughts. The only thing I can see, is that in the white outlined area there is a distinct clear gap in the dark shadow. I see it as two distinct oval patches of darker deposits.Therefore, I cannot visualise them as possible shadow.-sorry ~Pete

    Posted

  • wassock by wassock moderator

    But the bit in the middle is still darker than the non shadowed ground to either side. And it doesnt have to be a continuous tower of stuff casting the shadow. But equally it could just be a surface effect.

    Posted

  • wassock by wassock moderator

    Heres one that is a dust devil http://www.uahirise.org/ESP_013545_1110
    The track of the moving twister comes from the left and the shadow is down and right.

    enter image description here

    Posted