Planet Four Talk

Two Fans, Dark Material

  • msc386 by msc386

    Even though this image was easy enough to classify, it was no less interesting . There are two fans present in this image,
    both of which are weather-vaning in the same direction. The shape and relative darkness of both features suggests that
    they were created at approximately the same time from two distinct venting events. Furthermore, the data from the image
    suggests that surface wind velocity at the time was slow and steady, which would allow for more material to be deposited,
    resulting in the wide, dark fans as shown in the image data. Comment is invited.

    Posted

  • Kitharode by Kitharode moderator

    Hi msc. This image is from the 'Ithaca' region, which is a place I know nothing about. (I'm more of an Inca City spider fan) 😉

    Have you had a look at the HiRise image? Follow the 'View HiRise Image' link (bottom right of the image) and have a look at the 'JPEG Greyscale map-projected' image lower down the page.

    What you say makes sense, but there are so many variables to consider; size of vent hole, force of ejection, dust particle size, as well as wind speed and direction. That doesn't mean that what you say is wrong, I'm only suggesting that taking a wider view might help you with your investigations.

    Good hunting. Cheers, Kitharode.

    Posted

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

    Hi msc, at least these appear to be 2 distinct, large fans. So often when you enlarge an image you see smaller venting episodes within the main fan deposits. Many images like this,e.g. APF0000pn4 . Thing is to always look at the surrounding area on the HiRISE good luck with your ideas on venting.~ Pete

    Posted

  • wassock by wassock moderator

    Hi there, as Kitharode and Pete have said this is from Ithaca and this type of fan is very distinctive of the region. If you look at the HiRise image (click the link belownthe image above and then select the grey scale JPEG image from the list). This bit of Mars is regularly imaged and the "dog leg" feature bottom left in the map orientated image makes it easy to spot. If you look closely at the fans you'll see that they are mostly doubles, or more, including the 2 you marked. This is more obvious in early season pics where you'll typically see 2 fans makingva v shape.

    Often, viewed with the vent at the bottom the right hand fan is larger and the effect reminds me of the Federation logo that Cpt Kirk wears on his shirt. The space between the 2 tends to fill in as the sesaon progresses to give what looks like a single wide fan.
    your image is from April 2007, this one is the same area in Feb 07 and its easier to see the multifans

    http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/PSP/ORB_002600_002699/PSP_002675_0945/PSP_002675_0945_RED.abrowse.jpg

    This one's just too good not to embed , same area again, September this year

    http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/ESP/ORB_038000_038099/ESP_038040_0950/ESP_038040_0950_RGB.NOMAP.browse.jpg
    enter image description here

    Posted

  • msc386 by msc386 in response to wassock's comment.

    Wow! That is something. The different shapes of the fans is quite compelling; as is the blue frost associated with many of the fans shown
    in that image. (I find the blue frost quite intriguing.) Thank you for sharing this image with me. This image is yet another reason why I would love to go to Mars, LunchBox and Tool-Set in hand, and just go exploring. (And if possible, some kind of portable HHC with a connection to the 'Net so that I could talk to you guys. I wonder if they could make a pressure suit in my size...?)

    I know, it's probably a selfish fantasy, but I can still wish, can't I?

    Posted

  • wassock by wassock moderator

    Think we'd all like to go have a look. Most everyone is intrigued by the blue, and no-one seems to have a definitive handle on what causes it.

    Course there is a problem with carrying a lunch box whilst wearing a pressure suit 😃

    Posted