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MicroKid
2005-Feb-24, 08:30 AM
Sure looks like a muddy fluid flow from under the rock slab has built up a embankment here. Note the mud covered BBs and those uncovered on the down slope side of the embankment buildup.

http://img.photobucket.com/albums/v376/MicroKid/s-1P139018947EFF2809P2266L256R267croprsfmudzoom2.jpg

Then Oppy's tyre ran into the soil down slope from the embankment. Did I hear a "Squish"? Note the tyre track soil colour just to the right is much lighter and looks much more firm.

http://img.photobucket.com/albums/v376/MicroKid/s-1P139018947EFF2809P2266L256R267croprsfmudzoom1.jpg

Close up of the leading edge of the soil Oppy's tyre pushed up. It that a vertical mud wall rolling over the BBs now frozen in time:

http://img.photobucket.com/albums/v376/MicroKid/s-1P139018947EFF2809P2266L256R267croprsfmudzoom.jpg

Please take time to look at these images in xeyed mode. The extra detail is worth the effort.

01101001
2005-Feb-24, 09:01 AM
Sure looks like[...]
Too. Wide.

As ever, if wide images are necessary, instead of including them in-line, post a link to them, in the spirit of this article (http://www.badastronomy.com/phpBB/viewtopic.php?p=345344#345344) and of FAQ (http://www.badastronomy.com/phpBB/faq.php) ground rule 12:


This isn't so much a rule, as a comment: I will sometimes edit posts, but not for content. The script used by this board does some odd things; for example, a long link or big image will cause the board to be too wide.
Thanks. Again.

frogesque
2005-Feb-24, 09:15 AM
As well as the comments made by 01101001, the images have been overprocessed and I wouldn't draw any conclusions from them.

kucharek
2005-Feb-24, 09:48 AM
Sure looks like a muddy fluid flow...

Buzz Aldrrin, Apollo 11, after looking at a just taken core probe:

111:15:35 Aldrin: It almost looks wet.

...

[Aldrin, from the 1969 Technical Debrief - "...
At the bottom of the core tube, I had the distinct impression - and it's just a descriptive phrase - that this was moist material. It was adhering or had the cohesive property that wet sand would have. Once it was separated from the cutter, there was no tendency at all for it to flake or to flow."]


Just because things look like something, it doesn't mean at all that it is that something. And without the original images, I cannot assess how much they were tweaked to get the impression you get from the posted pictures.

Harald

wildone_106
2005-Feb-24, 09:17 PM
I dont think they've been "tweaked" more than contrast or color enhancement, but you can still plainly see the process's at work here, theres no need to hide behind that excuse, go check out the untouched" images at the JPL site which are and have been modified already before we even get them

Nicolas
2005-Feb-24, 09:24 PM
WIldone, with color and contrast enhancement one can fade out certain colours, and add sharpness to other colored areas. This might obscure surface details, hence processes.

And what do you imply with


go check out the untouched" images at the JPL site which are and have been modified already before we even get them

aurora
2005-Feb-24, 10:02 PM
Microkid:

Are you saying that the mission planners continually use their instruments on the wrong locations, since they have not yet detected lots of water in the ground?

MicroKid
2005-Feb-24, 11:00 PM
Here is a link to the original xeyed image (in .png format) made from the just released .img files. The left is the best that Horton could do with the limited filter data.

http://www.lipfordm.com/wtsi/s-1P139018947EFF2809P2266L256R267.png

It's 3.5mb

As for the apparent mud squish, I doubt Nasa pointed the mini TES at the "Squish" point. While the embankment buildup mechanics are very hard to explain without a fluid flow from under the rock slab I don't think it was active when Oppy passed by. The details in the trench would suggest however that this feature was active in very recent times (this past summer?).

My understanding of the mini TES is that it can only detect water on the surface or just a few microns under. The soil around here seems to have a hard crust which I doubt the mini TES could penetrate.

As for image processing nothing was done to brightness, contrast or gamma. No pixel alteration was done except as noted here. The image of the embankment was rotated 20deg ccw to compensate for the crater slope. All three images were resampled using a bspline filter at 600 bpi then refocused. The frozen leading edge mud wave hanging over the BBs is still clearly visible in the original.

I suggest using "Stereo Photo Maker" for viewing as the zoom and image alignment capability are excellent.

http://stereo.jpn.org/eng/stphmkr/

MicroKid
2005-Feb-24, 11:13 PM
There are other surface flow examples which the latest .img files help bring out the details such as:

http://img.photobucket.com/albums/v376/MicroKid/5304092_115254f609_o.jpg

http://img.photobucket.com/albums/v376/MicroKid/5304092_115254f609_o.jpg

Hmmm, wonder why the ring press is SO white and bright???

frogesque
2005-Feb-24, 11:16 PM
ROFL: Scared the heck outa' me with that one =D>

(Don't let GLP get a hold of that)

MicroKid
2005-Feb-24, 11:30 PM
This embankment building process is happening at many site outside and inside Endurance crater. Here is one site just below Burns cliff:

http://img.photobucket.com/albums/v376/MicroKid/1P152775574EFF37K5P2439L25crop.jpg

http://img.photobucket.com/albums/v376/MicroKid/1P152775574EFF37K5P2439L25crop.jpg

The down crater end of the rock slab even seems to be sinking as the soil is removed from under the slab and used to build up the embankment.

Here is a closer bw xeyed shot:

http://img.photobucket.com/albums/v376/MicroKid/1N153484383EFF37MIP0653R0M1croprsf.jpg

http://img.photobucket.com/albums/v376/MicroKid/1N153484383EFF37MIP0653R0M1croprsf.jpg

Anyone care to have a go at a non fluid based model for the creation of these embankments? Be sure to factor in that dust has an angle of repose of 20 - 30deg while for fluid / mud its close to or 0 deg.

01101001
2005-Feb-27, 10:42 AM
Anyone care to have a go at a non fluid based model for the creation of these embankments? Be sure to factor in that dust has an angle of repose of 20 - 30deg while for fluid / mud its close to or 0 deg.
I don't get what you are asking. Are you implying wind-whipped Martian soil can never be found to lie with a surface angle less than 20 degrees?

aurora
2005-Feb-27, 03:54 PM
Anyone care to have a go at a non fluid based model for the creation of these embankments? Be sure to factor in that dust has an angle of repose of 20 - 30deg while for fluid / mud its close to or 0 deg.
I don't get what you are asking. Are you implying wind-whipped Martian soil can never be found to lie with a surface angle less than 20 degrees?

Near as I can figure, he's saying that there is liquid that is actively running down the slopes.

If that hyposhesis is true, wouldn't the instruments on the rover be able to detect it?

01101001
2005-Feb-27, 07:32 PM
Near as I can figure, he's saying that there is liquid that is actively running down the slopes.

If that hyposhesis is true, wouldn't the instruments on the rover be able to detect it?
Oh, I know that MicroKid would like to think that Mars is a quite wet place.

I've never heard that the rovers have an instrument that can directly detect liquid water -- unless the cameras actually imaged a puddle. Maybe free water or ice would have a particular signature in MiniTES scans, but NASA surely would have hollered if they saw that. They have pointed out some instances of water bound in hydrated minerals, as this: "Rover Senses Bound Water" (http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040109a.html).

I just don't get how the angle of repose of dry Martian soil would lead one to believe that the effects pictured could only be due to a liquid. That angle could be used to argue against something being wet: if the angle of soil surface is significant, then that soil should be dry, in order to hold the shape.

But, it doesn't work the other way. I think MicroKid is pointing to the low areas by the rocks, with a shallow surface angle, and claiming they must be due to water because dry soil would have a higher surface angle -- at the angle of repose. No. Maybe I just don't understand his question.

It's also confounding to me because MircoKid asks for a non-fluid-based explanation for the images, and I believe a fluid played a major role in what we see -- the Martian atmosphere.

MicroKid
2005-Feb-28, 02:19 AM
[quote]Near as I can figure, he's saying that there is liquid that is actively running down the slopes.

What I'm suggesting it that the embankments buildup at the down crater ends of some rock slabs maybe due to the very occasional weeping of muddy fluid from under ground. This seems to be shown as only very few rock slabs exhibit this embankment buildup and they seem to be at about the same depth down the crater sides.


If that hyposhesis is true, wouldn't the instruments on the rover be able to detect it?

The mini TEs can only detect moisture on the surface or maybe a few microns under. If Oppy came back on a hot summer day and pointed the mini TES at an embankment buildup and sampled all summer long I do suggest the result would be positive.


Oh, I know that MicroKid would like to think that Mars is a quite wet place.

Actually I don't. But neither do I think it is a dry as some would suggest.


I just don't get how the angle of repose of dry Martian soil would lead one to believe that the effects pictured could only be due to a liquid. That angle could be used to argue against something being wet: if the angle of soil surface is significant, then that soil should be dry, in order to hold the shape.

My point was some have suggested that the embankment buildups are due to flowing sand / dust. But with level embankments and no dust inflow, the theory doesn't stack up.


I think MicroKid is pointing to the low areas by the rocks, with a shallow surface angle, and claiming they must be due to water because dry soil would have a higher surface angle -- at the angle of repose.

Correct. Also embankments buildups are darker than the surrounding soil and with the ever falling Martian dust giving everything the same colour, they must be very recent.


It's also confounding to me because MircoKid asks for a non-fluid-based explanation for the images, and I believe a fluid played a major role in what we see -- the Martian atmosphere.

You play at words. The atmosphere is a gas.

Wind driven dust / sand develops slopes when it falls. Slopes which form at the sand / dust particles angle of repose.

BTW how do you suggest this embankment buildup was formed? For the record I think the surface at this site was bone dry when Oppy snapped the images.

http://img.photobucket.com/albums/v376/MicroKid/s-1P139018947EFF2809P2266L256R267croprsfmudzoom2.jpg

01101001
2005-Mar-02, 09:35 AM
I just don't get how the angle of repose of dry Martian soil would lead one to believe that the effects pictured could only be due to a liquid. That angle could be used to argue against something being wet: if the angle of soil surface is significant, then that soil should be dry, in order to hold the shape.

My point was some have suggested that the embankment buildups are due to flowing sand / dust. But with level embankments and no dust inflow, the theory doesn't stack up.

You're not convincing me. I'm not sure what you mean by "level embankment". How does the angle of repose apply here? Do you see some Martian soil that is sloped more than the estimated angle of repose? I don't.

No dust inflow? There is always dust inflow on Mars. There is a vast supply and a moving atmosphere. Dust inflows. Dust outflows. Sometimes the wind keeps an area fairly clean, wiht outflow matching inflow, like the rover Opportunity and the small crack -- you call it "Broken Pipe"? -- between bedrock pieces, and some of the bedrock pieces themselves.



I think MicroKid is pointing to the low areas by the rocks, with a shallow surface angle, and claiming they must be due to water because dry soil would have a higher surface angle -- at the angle of repose.

Correct.

Huh? I still don't get it. The angle of repose is the maximum angle that the surface of a mass of particles will have to horizontal. The minimum is zero.



It's also confounding to me because MircoKid asks for a non-fluid-based explanation for the images, and I believe a fluid played a major role in what we see -- the Martian atmosphere.

You play at words. The atmosphere is a gas.

I do play at words. I play at using them correctly (http://dictionary.reference.com/search?r=67&q=fluid). (Note to self: When MicroKid says "fluid" he means "liquid".)


Wind driven dust / sand develops slopes when it falls. Slopes which form at the sand / dust particles angle of repose.

Maximally: angle of repose. Minimally: zero. Think of the sand in between the ridges of dunes.


BTW how do you suggest this embankment buildup was formed? For the record I think the surface at this site was bone dry when Oppy snapped the images.

[Image link] (http://img.photobucket.com/albums/v376/MicroKid/s-1P139018947EFF2809P2266L256R267croprsfmudzoom2.jpg )

Oh, I so love that "Broken Pipe" example. Here's a cropped image:

http://www.01101001.com/temporary/1P139018947EFF2809P2266L2M1crop.jpg

(In case anyone's wondering, the white disk isn't a UFO, but part of the rover's low-gain antenna.)

A lovely day that sol 122 (http://origin.mars5.jpl.nasa.gov/gallery/all/opportunity_p122.html) was. Such views Opportunity had there.

So, you really think it was caused by a liquid flow?

Before I go on, might I ask from where you posit the water/mud came? I suppose from underground, huh, so it could appear at the surface? And, what moved the water to the surface, against the force of gravity?

01101001
2005-Mar-08, 05:48 AM
Before I go on, might I ask from where you posit the water/mud came? I suppose from underground, huh, so it could appear at the surface? And, what moved the water to the surface, against the force of gravity?
Yeah, it's bothering me, too. How does that alleged liquid manage to find its way up from under that rock? Or, is the feature simply the result of blowing wind?

Maybe it would help if we knew where we are talking about. Where is the so-called "Broken Pipe"?

That cropped image above came from the Opportunity pancam on Sol 122 (http://origin.mars5.jpl.nasa.gov/gallery/all/opportunity_p122.html).

If we look at a recent Opportunity traverse map, we can see that on Sol 123, Opportunity was at the east side of the Endurance Crater rim, and it was there it turned around and headed back to the southwest to prepare for eventually entering the crater.

Traverse Map (http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20050225a.html)

http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20050225a/MERB_Traverse_Map_Sol_383-B388R1_th100.jpg (http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20050225a.html)

One sol earlier, Sol 122, Opportunity must have been very close to that point.

Here's a panoramic image of Endurance Crater (about 170 meters wide, and 20 meters deep) that includes "Broken Pipe", on the far left, just above the silvery low-gain antenna.

Panorama (http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040615a.html)

http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040615a/11-SM-01-Endurance-A160R1_th418.jpg (http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040615a.html)

Quite a veiw from up there! How high is that rim? 3 meters? 5 meters? More?

Here's a view from beyond the heatshield, Sol 361 (http://origin.mars5.jpl.nasa.gov/gallery/all/opportunity_p361.html), looking back at the eastern rim of Endurance.

View of Endurance Rim (http://origin.mars5.jpl.nasa.gov/gallery/all/1/p/361/1P160236096EFF4100P2363R1M1.HTML)

http://origin.mars5.jpl.nasa.gov/gallery/all/1/p/361/1P160236096EFF4100P2363R1M1-THM.JPG (http://origin.mars5.jpl.nasa.gov/gallery/all/1/p/361/1P160236096EFF4100P2363R1M1.HTML)

Wow. That's gotta be like just about the highest point for a couple of kilometers around!

What makes a crater rim higher than the surrounding land? Glad you asked. Here's a diagram of a few profiles of craters on Earth:

From Crater Morphology (http://rst.gsfc.nasa.gov/Sect18/Sect18_4.html)

http://rst.gsfc.nasa.gov/Sect18/craterprofile1001.jpg (http://rst.gsfc.nasa.gov/Sect18/Sect18_4.html)

The formerly flat sedimentary layers near the meteorite impact site are deformed upward by the cratering event, inclining away from the crater, no doubt fractured much in the process. Atop that falls the throwout from the crater interior, loose rocks and soil.

So, there is where my puzzlement arises. Where would the alleged liquid to create "Broken Pipe" come from? What made the liquid flow out there? What kind of "pipe" are we talking about? How many liters flowed there?

Was it a shallow source? Did the liquid simply flow by the force of gravity, from higher up on the rim? Well, the rim isn't very far away, at most a few meters. There just doesn't seem to be enough of a collection area there -- not that any precipitation has been demonstrated. And why did it flow out from under the rock, instead of flowing down though all that loose rock and soil of the rim?

Was it a deep source? Did the liquid get pushed up at "Broken Pipe" from a deep layer that crossed the plains, forced up onto the rim from the pressure of liquid kilometers away at higher eleveation? Well, then how did that liquid manage to thread its way through all the fractured bedrock of the rim without just finding its way into the much deeper crater?

How did the liquid get up that high? Whatever happened to "water seeks its own level"? That Martian liquid is very strange stuff indeed!

Alpha_Tauri
2005-Mar-09, 10:46 AM
How did the liquid get up that high? Whatever happened to "water seeks its own level"? That Martian liquid is very strange stuff indeed!

Permit me to act as devil's advocate to keep the argument going since nobody else is providing a worthy counter argument. (I don't actually believe the following, but please respond to it)

- Yes but that applies on Earth, where you have liquid groundwater. What about Mars where the groundwater/brine is frozen (citing temperature data) except for the few centimetres below the surface that is warmed by solar radiation.

If the surface temperature increases to about 20 degrees C during the summer, the ground ice below the area of solar warming will act as an impermeable barrier, and the evaporation of water on the surface will draw up water from below to form muds by capillary action through the soil pores. The upwelling of water would be largely contained within the pores of the Martian regolith, and any vapour produced within the pores would be at least partially confined, creating a hydrological pressure which would result in the water rising to the surface producing the mud which we so obviously see.

The water is much more stable in the regolith because it is at equilibrium with the water vapour in the pores within the regolith.

In addition, we have salt saturated material which will tend to act as a 'wick', drawing subsurface water to the surface.

aldo12xu
2005-Mar-10, 05:47 PM
Alpha, your hypothesis was actually put forth by G.A. Landis in the link below. He used it to explain how duricrust may form.

http://www.lpi.usra.edu/meetings/lpsc2004/pdf/2188.pdf

Landis also has a Top Down model whereby "transient liquid" from melting frost is drawn downward by capillary action, dissolving salts/sulphates from the regolith along the way. What if we extend this proposal:

Frost is deposited in the small intervening troughs between individual ejecta blocks. This is where we'd have the thickest accumulation of frost. The frost melts, the transient liquid mixes with the soil, sulphates get dissolved, creating a briney solution. An icy crust may form on top of the briney liquid, insulating it and allowing more sulphates to be taken into solution, further reducing the liquid's freezing point. If there's a sufficient accumulation of this solution, could not continued intermixing with the soil create a mud like paste that could potentially produce a viscous flow for a brief period?

Here's another paper that attempts to gloabally quantify the potential for transient liquid water to exist on the surface, even if for short periods of time. In particular see page 6 and Figure 3.

http://www.agu.org/pubs/pip/2004JE002367.pdf

Cheers,
Aldo.

01101001
2005-Mar-10, 06:34 PM
That all may be fine for some feature called "Drippy Faucet", but here we are discussing something some call "Broken Pipe" claimed to have the characteristics of flowing liquid, to have sculpted the area below in a way that any Martian wind could not, that built an embankment.