Planet Four Talk

Features in Blotches

  • wassock by wassock moderator

    this image seems to show a transition between smoother terrain top left (or maybe its just sloping down and is in shadow) to an area with blotches and lots of fine spiders. Most of the dark blotches have circular features in the middle which appear to have the opposite shading to the spiders, making them raised features - boulders. To me they look like little volcanos with craters on top but only if the sun is top right

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  • Paul_Johnson by Paul_Johnson

    I'm not sure if the boulders are causing the mini eruptions, or they form above a blow hole.....what do you think wassock?

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  • wassock by wassock moderator

    the wisdom from those who've been looking longer is that the boulders rest on the surface, part covered by the surrounding ice. when the sun shines the boulder catches the sun and warms, melting the ice around it and letting any underlying gas out. I think the theory is that in the spring this starts to happen at dawn, gas escapes then the hole freezes up again come night fall, then the next morning, same again.

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  • Paul_Johnson by Paul_Johnson

    How does the ice boulder get there in the first place, though? Surely a gas vent constantly blowing and freezing would create such a feature, like a stalagmite, over hundreds of cycles......I like the idea that these boulders are Martian ice stalagmytes!

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  • Portyankina by Portyankina scientist in response to Paul Johnson's comment.

    The boulders are not ice boulder, but normal, stone boulders 😃
    They survived 3 summers since I monitor them. And even did not move. I am also wondering, where from they came - there are no craters nearby this location to create lots of debris. And also how comes they like to stick on the inclined surfaces like this one.

    Anya

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  • wassock by wassock moderator

    May be stalagmite is not so far from the truth, presumably they have blotches or fans every year so theres evidence that material moves over them, all you need is a way of getting some of that to deposit and you can grow your ownboulders

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  • wassock by wassock moderator

    Actually you have a system where a gas particulate mixture decompresses repeatedly at the same point over a long period of time. i it would almost be unusual if there wasn't some sort of deposition going on?

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