a martian oddbox

[ArMaP]

I neglected to add a link for sheer drop sanddune

http://mars.jpl.nasa.gov/msl-raw-images/proj/msl/redops/ods/surface/sol/01194/opgs/edr/ncam/NLB_503501870EDR_F0512704NCAM00271M_.JPG

it looks to me like it could be 3 storeys high , what could possibly cause this ?

I don't think it's that high, this camera has a wider lens than the mast cameras.
As for what could cause this, gravity.

notice the ghostly looking fez wearing face on the top pic to the far right on the clifface of the dune

Maybe it came from Casablanca. It's looking at you, kid.

[funbox]

I don't think it's that high, this camera has a wider lens than the mast cameras.
As for what could cause this, gravity.

ide take that more of an excuse to it's dumbfounding probability, if it had been one of the front or back navs, right and left are nowhere near as prone to fish eye as the aforementioned

Maybe it came from Casablanca. It's looking at you, kid.

portentous. the joke, so so , but the seeing and agreeing without question ...
hmmm

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[ArMaP]

ide take that more of an excuse to it's dumbfounding probability, if it had been one of the front or back navs, right and left are nowhere near as prone to fish eye as the aforementioned

I suppose you mean the hazcams, those are the ones with the fisheye lens.

These are the focal lengths for Curiosity's cameras:
Hazcam: 5.58 mm
Navcam: 14.67 mm
Mastcam (left): 34 mm
Mastcam (right): 100 mm

portentous. the joke, so so , but the seeing and agreeing without question ...

I see what other people see most of the times, the difference is in the interpretation.

[funbox]

I see what other people see most of the times, the difference is in the interpretation.

so you interpret this sand dune as homogenous ? is that sand all the way through to unknown x distance , where harder rock gives support and shape or does it reach the other side of the dune just as sand./unknown gritty appearing conglomerate  ?

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[ArMaP]

so you interpret this sand dune as homogenous ?

Yes.

is that sand all the way through to unknown x distance , where harder rock gives support and shape or does it reach the other side of the dune just as sand./unknown gritty appearing conglomerate  ?

It's probably just sand, on Earth we also have large dunes, the biggest of all is 1230 metres high.

[funbox]

It's probably just sand, on Earth we also have large dunes, the biggest of all is 1230 metres high.

and here on earth does said dune stand solitary ? or is it a by-product of the topography of the region its in and its of a family  of similar sizes ?

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[ArMaP]

From a quick look at the biggest dunes, those huge ones are "lonely" dunes, they probably gathered all the sand available on their area.

This one on Mars may be the only one on that specific place, but the area where Curiosity in entering now is full of dunes.

[funbox]

From a quick look at the biggest dunes, those huge ones are "lonely" dunes, they probably gathered all the sand available on their area.

This one on Mars may be the only one on that specific place, but the area where Curiosity in entering now is full of dunes.

who are they and why are they gathering sand ?



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[ArMaP]

who are they and why are they gathering sand ?

"They", on my previous post, means "the dunes".

[funbox]

"They", on my previous post, means "the dunes".

so you're saying this colossus sanddune , somehow managed to gather more sand than the surrounding area without having some underlying structure to trap and shape ?



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[ArMaP]

so you're saying this colossus sanddune , somehow managed to gather more sand than the surrounding area without having some underlying structure to trap and shape ?

Yes, that's how dunes "work".

[funbox]

Yes, that's how dunes "work".

interesting , I always thought topography had something to do with it , very industrious of them, so how's it done then?
what are the driving and cohesive forces at work here?

seems a bit much for the asthmatic wind to achieve alone, let alone the weak gravity

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[funbox]

a mild influx of pictures

this dune looks so fake

remember the markings on this one ArMaP.. do they seem familiar to you ?



http://mars.jpl.nasa.gov/msl-raw-images/msss/01194/mcam/1194ML0054190010502903E01_DXXX.jpg

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[ArMaP]

interesting , I always thought topography had something to do with it , very industrious of them, so how's it done then?

Topography has an influence, but not that much.

what are the driving and cohesive forces at work here?

Mostly wind and sand.

Wind blows the sand, the sand grains, according to their weight and shape, fly, jump or roll until they find an obstacle. This obstacle doesn't need to be big, only large enough to stop the flow of the sand and make it accumulate on the side of the obstacle that faces the wind.

From that point only wind and sand are needed, as the "new born" dune will act as the obstacle that will gather more and more sand.

When the side of the dune facing the wind has an angle low enough the sand moves over the dune and falls on the other side, and this side is steeper than the other, as it is formed by the falling sand. As the sand keeps on climbing the side facing the wind and falling on the other side, the dune will advance in the direction of the wind, at a speed that depends on force of the wind. Winds that are too strong may destroy the top of the dune and stop if from advancing until the top is recreated by the accumulation of sand.

seems a bit much for the asthmatic wind to achieve alone, let alone the weak gravity

The  Martian atmosphere was, supposedly, denser before, so at that time it was easier to make dunes, while the low gravity helps moving the sand. Also, the lower gravity allows steeper sides, like the one we see on the photo and that I suppose is the side opposite to the wind.

Even at present, with the thinner atmosphere and weaker winds, moving dunes have been seen on Mars.

[funbox]

Mostly wind and sand.

Wind blows the sand, the sand grains, according to their weight and shape, fly, jump or roll until they find an obstacle. This obstacle doesn't need to be big, only large enough to stop the flow of the sand and make it accumulate on the side of the obstacle that faces the wind.

From that point only wind and sand are needed, as the "new born" dune will act as the obstacle that will gather more and more sand.

When the side of the dune facing the wind has an angle low enough the sand moves over the dune and falls on the other side, and this side is steeper than the other, as it is formed by the falling sand. As the sand keeps on climbing the side facing the wind and falling on the other side, the dune will advance in the direction of the wind, at a speed that depends on force of the wind. Winds that are too strong may destroy the top of the dune and stop if from advancing until the top is recreated by the accumulation of sand.

it makes no sense , why such a huge sanddune in comparison to the shorter dunes that are in patches and are of the same material. whats so especial about this one ?
a hulking great construction u8nderneath perchance ?

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