Planet Four Talk

Did someone implement an 'erase' tool?

  • wassock by wassock moderator

    Think this is the evolution/degradation area or nearby - Big image warning - ready your mousewheel (Feb 2013 image http://www.uahirise.org/ESP_030790_0925 ) This is the RGB colour JPEG image

    So at the top polygonal cracks with associated fans, so far so normal. Now scroll all the way to the bottom..........

    enter image description here

    So what's this all about? Lots of martian motorists with their headlights on in the dark? NB if you look real hard the light colour 'fans' are present even at the very top of the image.

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  • mschwamb by mschwamb scientist, translator

    Could be new frost coming out of the vent and covering the previous fan.

    Cheers,

    ~Meg

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  • p.titchin by p.titchin

    Brilliant colour strip and frost fans. I note it's 19th february 2013 acquisition. Must say something about temperature for that amount of new venting Oh for a 'time lapse photo ' video. ~Pete

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  • wassock by wassock moderator

    I think it's some kind of surface effect, Will now go look (when I finish tiling the bathroom), my prediction is that I will find earlier dark fans in the position of the bright ones.

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  • mschwamb by mschwamb scientist, translator in response to wassock's comment.

    If that's true and you see that then the particles sinking through the ice theory would be likely make sense here. This is partly what my summer student was looking at in August. Still very much an open area I think.

    ~Meg

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  • wassock by wassock moderator

    We've seen similar before http://talk.planetfour.org/#/boards/BPF0000009/discussions/DPF0000egy relates to a 2010 image of much the same area I think, and somewhere theres a thread which shows dark fans turning light. Which I cannot find for the mo'

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  • wassock by wassock moderator

    The bright fans are already there in the first pic of the season (every year). I'm reading the increasing dark as fan material building up as the season progresses. It could bensome sort of camera/contrast effect but it repeats each year. So if it gets darker as mor fans erupt then theres some sort of force field protecting the bright bits, or summat

    November 2012

    enter image description here

    February 2013

    enter image description here

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  • Kitharode by Kitharode moderator

    Most of the 'baby' spiders don't have fans in the first image above and they remain as bright spots in the second. Same thing applies in the mega-long image previously (?)

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  • wassock by wassock moderator

    Yes noticed that, which is why I wondered if it was some sort of image brightness/contrast issue

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  • wassock by wassock moderator

    This is from the same area, very early season October 2016 - the baby spiders are very bright even then. There seems, to me leastwise, to be a bit of a theme going on here - same thing all acrocc the big image. Any one else see it or am I just seeing shapes in the clouds?

    http://www.uahirise.org/ESP_029048_0925

    enter image description here

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

    Hi Wassock, more fascinating images. I suppose that once the spiders have formed, they are there for a very very long time. I notice that most don't seem to have much, if any, significant venting in these views, and so I presume these 'baby' spiders' are not undergoing much further development at present., but they will be visible and largely unchanged in any views we get. The white frost fans seem to be big venting episodes, with the origins not as numerous as the dark fans, and dark material venting occurs within the large white fans, often showing 'linear venting'., as well as venting from the same point of origin as the white frost. So much to ponder on! ~Pete

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  • wassock by wassock moderator

    Hi Pete, this is very early season so the venting hasn't really got going yet. But what fans there are, are associated with the small spiders. This image correlates with the earlier ones in this thread where the small spiders stay bright and visible whilst all around them gets darker and darker.
    My outline theory for the white bits is that what ever made them is in some way different from what makes the dark ones, even though both come from the same vent. There's another thread somewhere where the white fans (in a different area) start out dark, but I can't find it at the mo' What's interesting is why the white ones persist as all around gets darker, presumably due to subsequent emmisions of dust. Some of this dust must be falling on the white bits but tjhey seem to remain undimmed.

    What do you think wrt the shapes of the babies?

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

    It's possible that I'm confused (nothing new there then) but I think in the HiRise images the sunlight comes from the opposite direction to that in the P4 images, ie, from the left-ish (?)

    If that is the case, then the baby spiders become baby bumps. (A pregnant pause might be in order here). What say you?

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  • wassock by wassock moderator

    OK same area, a Mars year later, this one ESP_038082_0925 10 September 2014 HiRise

    enter image description here

    This one ESP_038438_0925 8th October 2014 HiRise

    enter image description here

    As I look at it the early lightly greyed area in the three main fan systems here have all turned 'white' a month later. So either the dark turns white of we get a series of later vents, matching the first lot direction wise which are comprise of something different which shows up as white. Oh and in this scenario there's a whole forest of other vents starting up which are still spewing out the black stuff which also overlays the white (and I can't see any dark fans overlain by the white. So which of these options is more likely, or are there otherways to get between the 2?

    And the baby spiders don't appear to have a whole lot to do with all the fans.

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  • mschwamb by mschwamb scientist, translator

    Nicely spotted! You're thinking and thoughts is where the idea that some of the frost being that the particles sink into the ice and then melt the ice and it freezes slightly different in structure to produce the color change. The thought is that there's more material closer to the vent so that stayed dark where the thinner outer parts of the original fan sunk and then new fans appeared.

    The protospiders are interesting. I hadn't seen something like that before.

    Cheers,

    ~Meg

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  • wassock by wassock moderator in response to mschwamb's comment.

    I am on message with that Meg, my theme is why is it only the early fans which go white and why do they persist when all around them gets infilled by the later dark fans. Late season all of it is black apart from the white bits.

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  • mschwamb by mschwamb scientist, translator in response to wassock's comment.

    Hi Wassock,

    Good question. It might be duration. That these fans that went white were around much longer before imaging started. I've definitely seen cutouts on Planet Four where than the whole image has tons of fans like the image you show and then later it has gone white or blue/green. I don't this is a solved issue. Hopefully everyone's markings will help shed some light.

    Cheers,

    ~Meg

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  • wassock by wassock moderator in response to mschwamb's comment.

    Don't think it's age, the second image above is SL 210 whereas the first one on this thread is from the year before but at SL 267. I shows the same thing as the above 2. If it was just a 'time on the surface' issue than we would expect to see more white fans developing (the white fans her have taken less than a month to develop, SL194 to SL210) - they don't, the original crop from early season (probably the first venting activity) persist all the way through.

    My idea is that the dust in the first venting (the initial sneeze) has a different make up to what comes out later - maybe the first lot is much finer or something like that which will give it different surface properties and affect the way it reacts with the ice. (which is also presumably a lot colder early than later). Maybe the first sneeze is all "rock salt for CO2" which makes the area it lands more able to self clean?
    The main conundrum is that the white fans seem immune to the attentions of the dust from the fans around them.

    Looking at the bottom end of the first image on the thread the surroundings go totally black, It's inconceivable that some of this material is not also landing on the white bites but they maintain their definition.

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  • mschwamb by mschwamb scientist, translator in response to wassock's comment.

    That's an interesting theory. I think that could be what's happening. Hopefully fan spreads and lengths from Planet Four will help determine if that's what's going on.

    Cheers,

    ~Meg

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  • wassock by wassock moderator

    As a side issue, this effect doesnt appear all over, seems restricted to this area, unless anyones seen similar elsewhere?

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