I'm a newbie and not too adept at internet stuff. But I have been following the Mars rovers pretty closely. In December, when Opportunity was making its way out of Endurance Crater it took photos of rock slabs, several of which had what looked like muddy water around the base. About the same time the NASA Mars site announced the discovery of conditions that would indicate an ancient site of a sea bed - a conclusion derived from geology, not the current presence of ground water. I have downloaded those photos but I'm not sure how to send them here with a posting. I did not keep most of the URLs with the photos, only the lengthy NASA/JPL id codes for each one. I would love feedback from an expert on these photos, but never received a reply from NASA when I wrote them (They ARE a bit busy these days!) I'll be happy to send these photos to this site if someone can tell me how to do it. I have Windows XP. Thanks


Here’s the one URL I do have: http://qt.exploratorium.edu/mars....0M1.JPG

It looks even more like water if you can zoom in on it.

I know Mars is too cold to sustain liquid water, but this looks more like the way a fluid acts than fine dust particles. A few days ago Spirit was moving through Rocky slabs that looked similar to these and there was much fine dust. The way it was settling on and around rocks was not as distinctively liquid like as that at the Opportunity site. I’d like to know if there some other liquid that may be on Mars that may tolerate the cold. Titan has colder temperatures and has methane seas.

Hey Dawg,

I think I know the pictures you were referring to. I have a few on my site. Just go to the Fluid Flow link under the Opportunity section. Some people say they're the result of wind action, but they might be formed by intermixing of frost, soil and fine dust occurring between ejecta blocks.

Cheers,
Aldo.

Liquid water can not exist on mars given the temp and pressure. It's that simple.

Dust can do very very strange things in low gravity environments The things you have on your site Aldo - seem like classic wind errosion to me.

Doug

I wonder if that's true in all cases. There are in fact cirumstances at Mars above 0 celsius. Not often, but it happens. The only aspect left then is lower pressure than earth atmosphere.

Water can be "interstitial" (built in in crystals, like gypsum) and it can be adhered (absorbed) to the cation exchange faces of clay-minerals. Clays (micron scale particles) mostly consist of parallel plates of crystaline minerals. Between them, water and it's dissolved chemicals can be very strongly bonded. We are not talking about micropores, it's a system on atomic/molecular level. The adsorption properties of clays can be REALLY amazing. For example, i am thinking about the so called swelling-clays. Once they're wetted, they swell and enormous pressures can exist inside the microstructure. In this way, water actually is fluid, despite low pressure in the ambient atmosphere. It is in small amounts, it is distributed in very fine layers......but i think it actually could infuence the physical properties of the medium in a way that it behaves fluid or plastic.

Marcel.

The paper below came up with a model where "transient liquid water" has the potential to occur based on global variations in surface pressure and temperature (Figure 3). At Meridiani the model estimated that there are 1 2/3 hours per day for about 60 days per year where the criteria are met for the potential for transient liquid water to occur (page 6). Granted, the paper is still unpublished, but it does seem to be well supported.

Richardson, Mark; Mischna, Michael, — December 2004
The Long-Term Evolution of Transient Liquid Water on Mars

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

Thanks for the feedback. I am not a scientist, only endlessly curious and excited about discovery, so I can only learn from what you guys say. Aldo. your web site is really terrific! Thanks. Looking at your Opportunity "movie" I can more easily see the "dust" lying flat in several locations I had not noticed before. Particularly at the base of thelarge shoe-like rock near Endurance. Perhaps it is only fine dust that simply behaves like a liquid when gravity settles it down. But I still have some questions.

In early December the NASA web site noted, in text, that there were some flat rocks (in the area I see the flat-lying liquid-like dust) that looked the same but were very different in shade - some light some much darker. To me the darker shading looks like it could be wetness. I have a photo of RAT working on a two-tone rock, making one hole in the ligher section and another in the darker section. The residue from the darker section hole has fallen into the "dust" puddle!
The inside of both holes looks pretty much the same.

I saw no text at the NASA site explaining what they found in these two RAT holes.

If someone can explain to me how I can upload this picture to this site, I'll gladly do so.

Dawg

Hey Dawg, thanks for the compliment.

If the pictures are on your harddrive the only way you can post it is if you a website to upload it to. If you don't there must be a way of attaching it to reply, so maybe do a search in the help section of the forum.

If you're getting the picture off the net (eg off of NASA's site) just copy the URL from the address and paste it in your reply. The forum's program automatically creates a link.

Hope that helps!

When you make a post on this forum - there's a 'File Attachments' section just under the main text box - browse for the image, and then when you post - it'll get uploaded

Doug

Thanks, folks!

Here's one, I hope, and I'll send more if this works:

Oops! Here's the one I meant to send, with the two RAT holes:

I'm trying t send two at once:

Here's a blow up of the first one I sent:

I see wind blown dust and not a lot else.

Doug

I've seen this one referenced elsewhere as evidence of liquid water being present on Mars today, and although the sand has formed a very smooth surface at that spot, it is far from level. The image below should give a better idea of what the angle was like on this surface.


http://origin.mars5.jpl.nasa.gov/gallery/a...EVP1724L0M1.JPG

Doug,

Do you really see the last photo I sent as looking more like wind-driven dust than like water? Wouldn't wind-driven dust tend to pile up along the edges against the rock? What would happen if we were to twirl a stick in the dust? Would it scar the surface like a half-dried mud puddle? Would it make ridges like a sand pile? Or would it roil up into a cloud of red dust and, eventually, settle into a perfectly flat, limped pool again? I've been looking at these photos for six weeks. I have attempted to see them as they are, not filtering them through pre-concieved ideas of what they should be. They probably are dust. But they LOOK like pictures of liquid. I am not an Earth scientist, but I would like to see something like these photos of dust somewhere on Earth. The physics of the two planets should be the same. Or maybe not.

Hi Dawg -
You have to remember that the rover is parked on the cliff while taking those photos, giving an impression of a more level surface. If you rotate the picture the 27 degrees or so that (IIRC) Burn's cliff tilts, you can see they aren't really "puddles":


This brings me to my completely amateur Pachinko Machine theory of sand deposition - grains are blown in by wind from the plains, and cascade down the path of least resistance, leaving piles at the bases of the rock faces. Like in CG animation when you model water, you really model particles flowing to approximate it, sand can look and act like liquid. I would imagine the lower gravity of Mars may contribute to this effect.

The thing is, it's Mars, and water doesn't obey Martian gravity, and it also happens to be the color of sand.

This pic shows the detail pretty well - you can see the sand clinging to the cliff wall and then stream into the "puddles"

I can see WHY people might go "puddle" - but that's not what it looks like to me.

It just looks like fine wind blown dust.

It's everywhere, lots of nice smooth dunes, nice downwind tails from rocks, these are nothing different to me.

Doug

Hi, Slinted,

I noticed this shot as well, and it does give the impression of a slanted landscape. I thought that this was just the effect of the the camera angle, since the cameral is more directly above the rocks and "liquid" in question and the horizon is at some distance. Also, the edge of the horizon is so dramatically curved upward that I thought it might be a lense effect. Maybe you're right, though, but I don't think it's a slam dunk.

Hi Dawg,

This was an area that was explored as an alternative exit route, I'd imagine because it was relatively not all that steep, but the entire crater wall at this location was at a downward pitch. I'm not 100% sure if this is true or not, but it seems like there was no exposed outcrop here that was horizontally level since almost all of it was seen on the walls of the crater. This image, taken on Sol 103 from above the rim of the crater before they even descended inwards should better illustrate the downward slope of all the features in this area. Yes, the rover was tilted when this image was taken, but even given that, you can see the large expanse of sand in the middle of the frame (the same sandy area above the rocks with RAT hole in the images you posted) as being on an angle.

http://www.lyle.org/mars/imagery/1N1373314...88L0M1.JPG.html

The sandfall into the crater has created some interesting 'flow like' and 'pool like' features, but I think they can all more easily be explained by the smoothing actions of wind blown and gravity driven materials rather than the more unlikely scenario of surface exposed liquid water.

When I first saw the close ups of Endurance, I thought at best those features might have been water "stains" - that through the eons, condensation or what not caused rare flows that discolored the cliff faces. But now I really think its just the darker plains material pouring in over the lip of the crater. The pictures from when Opportunity got closer reveal the dusty sand (or sandy dust????) particles.

The PanCam pics show this best, since it shows detail that it can't be liquid:
Burns Cliff

Burns Cliff 2

If you tilt these pics counter clockwise 20 degrees or so in your mind, you can easily see how the dust falls down from cracks above, ending in "pools" of sand.

Also, I believe the spectral results show it to match the plains sand as well, though I do not have that info as a link off hand. Anyone?

I'd have to agree with the others. Dawg, those are examples of very fine-grained windblown sand/silt. The examples I had were outside of Endurance and I thought were examples of the sand/silt becoming "liquified". Granted, I'm not familiar with all aeolian processes and how they can sculpt the landscape, so I'm still open-minded.

djellison (or anyone else), I'm familiar with moats and wind tails, but would you be able to point me to a source that would show terrestrial examples showing something similar to the lobate features in the photos I posted. For example, in the photo below, the feature that bugs me the most is shown by the arrow, where the material seems to be "dripping" into the hole. Thanks, in advance.

http://www.tobescene.com/Misc/Mars/Flow_Hole_LR_2.jpg

And, dawg, here's a free site that lets you post your photos as albums:
http://www.flickr.com/learn_more.gne

OK, so I guess I'm outvoted! But, of course, empirical science is not a democracv.
It probably is dust, but if incontrovertable "proof" does come in that some of these photos show a liquid would you folks support me in having one of the sites named in my memory? You know, like "Dawg Puddle"?


I am still perplexed about the "two-toned" rocks that NASA was curious enough about to make two RAT holes in one. It may be, as someone suggested, that the rock was stained be some other material pouring over the crater edge, but why didn't NASA make any comment to this effect?

Dawg