Water on Mars

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PostPosted: March 22, 2011 12:48 PM 


Summer brines on present-day Mars?


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PostPosted: March 22, 2011 1:07 PM 



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PostPosted: March 22, 2011 2:53 PM 

Interesting article!

Why not? The conditions are ok for such on Mars (even for pure water in midsummer).

A research project of the TU-Berlin is currently investigating in salty brines under martian conditions - inspired by those elusive Phoenix droplets btw.

Until now they only published some short notices in german about the project so i cant profide a link


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PostPosted: March 22, 2011 4:00 PM 



Links to relevant lpsc2011 abstracts.


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PostPosted: March 23, 2011 4:15 AM 

Thanks for the links above Barsoomer. I guess I need to recheck this location for "timelaps" observations (PSP_007162_1915):

In this crop the dark streaks or TSL as they are called in the papers above also appears to orginate from rocky outcrops only (trouoghout the image strip of that slope in Arabia Terra).

Kevin Author Profile Page

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PostPosted: April 5, 2011 11:53 AM 

In this release it says findings from Pheonix show there is a water cycle of some sort, if not a dynamic one happening on Mars:



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PostPosted: April 5, 2011 1:07 PM 

Some more recent mars-water related stuff:


Martian-Fog Study Finds Thick Haze, "Diamond Dust"
NASA lander adds to evidence of red planet's water cycle.


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PostPosted: April 5, 2011 3:36 PM 


This article suggests that Earth had acid conditions when life began and only later transitioned to alkaline. This seems to be the reverse of what happened on Mars. Curious.

Kye Goodwin

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PostPosted: April 5, 2011 4:25 PM 

MPJ, re your 4, Opportunity has recorded many dark slope streaks originating from rocky outcrops, including some in Victoria Crater large enough to be seen from space (image center):

A very different crater, tiny, fresh Conception, also has several dark slope streaks. Two are clear in the bottom left corner of the image, widening downward on dark fine sand slopes on the crater wall:

In Oppy's image library slope streaks occur at Endurance, Erebus, Victoria, Conception and Santa Maria, at least. The variety of geological settings in which slope streaks occur is amazing, just considering the Meridiani traverse alone. I haven't come across any references linking the rover images of streaks with the orbital images. I find the apparently active dry streaks imaged close-up at Endurance and Erebus to be just as amazing as any indication of wet streaks would be.


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PostPosted: April 5, 2011 4:46 PM 

Sol 2544 ( Mar 21, 2011 ) of target Aji:

A full filter sequence was taken of this target - but only the L2 R2 have been downlinked so far.

Notice that the dark "streaks" below the cliff look similar to the possible brine streaks in the paper TRANSIENT SLOPE LINEAE: EVIDENCE FOR SUMMERTIME BRINY FLOWS ON MARS? cited in reply 3. ( Although 10 times small in size )

Here is a view of Aji from the NW rim ( to the right of the Astronaut ).

These streaks have puzzled me since Burns Cliff.

Kye Goodwin

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PostPosted: April 5, 2011 5:22 PM 

Horton, re your 6, I have posted a longer reply to MPJ's 4 prior your 6 appearing, but it hasn't shown up yet. Thanks for connecting the slope streaks that Oppy has seen with the orbital images from other places on Mars. There are streaks at Endurance, Erebus, Victoria, Conception and Santa Maria, at least. Some at Victoria are visible from orbit.


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PostPosted: April 5, 2011 8:10 PM 

Most dark slope streaks are thought to be dust avalanches. The authors of papers claiming water flow are careful to apply several lines of evidence to rule out simple dust flow.

Kye Goodwin

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Reply: 12

PostPosted: April 5, 2011 9:54 PM 

Barsoomer, re your 11, Yes, but how likely are the slope streaks at Meridiani to be dust avalanches? We would expect to see dust avalanches on dust loaded slopes, with a break-away zone at the top. Most of the streaks at Meridiani don't fit this description. For example, many of the streaks in Horton's view of Aji, linked in reply 9, seem to originate in the rock outcrops. Also, there doesn't seem to be any depth of material to avalanche. Those streaks look like dry trickles of material not sudden slides of accumulated material. I think that those dry trickles are hard to explain. They aren't hard to explain away, if we're not really interested. They could be just a wind-powered phenomenon where aeolian deposits are now sliding down slopes, but I no longer find this explanation plausible. There just isn't a good enough reason to expect the wind to create unstable particle accumulations in the particular places where we see streaks. Also, it seems that these trickles below outcrops can, in time, develop into deep deposits (center far-right):

I think that these trickles of material from crater outcrops are related to the mysterious rapid erosion of crater interiors. This is a very simple theory in some ways.


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PostPosted: April 5, 2011 10:17 PM 

Kevins post reply 5 Very Happy I knew it, there is a dynamic water cycle, everyday, ice fog, falling to the surface.
now for sure we know why the soil cracks like it does, and why there is an interaction between soil /rock interfaces.

Like in the desert, rocks might pick up small amounts of this frozen moisture, and bleed them out. I have seen rocks on the pavement, leaking water, in the middle of a 100 degree day, having seen no rainfall for months.


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Reply: 14

PostPosted: April 6, 2011 12:14 AM 

Hort; I believe those isolated fragments are not in place and have slid down the slope.
( "float" in geologic terms) which are abundant around cliffs and steep slopes.

If they are float ,they are not connected to the adjacent wall therefore liquid seeps would be unlikely.

I seem to recall seeing similar small avalanches of dust around home plate but they were less conspicuous because they were the same color as the rock under them.

Kye, I am pleased that you consider these "trickles" to be eroded dust .
They may be related to more rapid erosion because the source rocks have been subjected to impact and may be softer than surrounding rock.


Kye Goodwin

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Reply: 15

PostPosted: April 6, 2011 2:31 AM 

Ben, re your 14, I think that we should be calling the dark trickles from outcrops sand, rather than dust, because the fine material seems to be moving down slope by gravity and staying together in distinct tracks while we might expect dust to blow around and disperse once mobilized. I also have to wonder what kind of erosion could be creating the sand trickles. It just about has to be chemical activity of some kind if its not wind, but why would chemical weathering of the outcrop be creating such a uniform fine product? An outcrop falling apart into pieces of all sizes is a more common outcome on Earth. Pre-sorted talus is strange. What do you think is the origin of the slope deposit below Namib (top center in the image)? It sure looks like a gravity-built structure to me in this light:


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Reply: 16

PostPosted: April 6, 2011 2:35 PM 

Kye; I agree , the slope deposit appears to have been built by gravitational fall of material removed (by erosion?) from the under side of the overhang.

This overhang appears to be a more resistant lense (of an unknown source) in the Meridiani beds and as such may contain a greater concentration of dark minerals.

The under side of the overhang could be subject to different environmantal conditions as well.


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PostPosted: April 6, 2011 6:56 PM 

I can't understand how some scientists think. There is a simple solution of the problem of the seeps contained in Barsoomer's and Kevin's earlier posts and yet the obvious is ignored and the discussion confined to other much more exotic solutions to the problem. Haven't most of you heard of Occam's razor?



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PostPosted: April 6, 2011 9:10 PM 

Hi All

Sorry about the tone of that last post. Feeling somewhat down today.


Kye Goodwin

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PostPosted: April 6, 2011 10:12 PM 

Ben, Re your 16, OK, Thanks, I've got you describing that deposit below Namib in Endurance (Reply 15, top center in the image). Now go one step further with me. I can't help but see a strong resemblance between the structure under Namib and the structure on the north-west wall of Santa Maria:

To me the dark fine-textured wall structure in the images above appears to be a gravity deposit much like the structure in Endurance. The two occur in about the same position in their craters, below a rocky outcrop at the top of the wall. In the last image we see only the west end of the deposit at SM which ends downslope on a bare crater wall much like the one under Namib. It is really hard for me to believe there is no connection, that these structures were built by completely unrelated processes.

See also in the last image many dark trickles of material originating from outcrops in about the same slope position as the big dark deposit, far right. It is hard to avoid the idea that the dark trickles have sometimes become deep deposits.


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PostPosted: April 7, 2011 12:26 AM 

Kye; The differences I see are, the rocks at the top of the slope are not a resistant ledge but instead are a rubble pile of Meridiani bed ejecta that has accumulations of dark sand/dust interspersed between the blocks all the way to the top of the slope.
I consider this as strong evidence for the material being blown upward out of the crater and being trapped in these crevices.

On the west end where there is a more resistant ledge , the dark sand sheet encroaches the ledge upward from the bottom and appeares to thicken downward, particularly in image 3 where wind has sculpted the thicker layer near the bottom ,into the ripples shown.

The last image is inconclusive and the small trickles may be gravity fed from erosion
of the rock above. This would imply that a minor amount of the sheet could have a similar source.

Oh for a photo of the wind deposits I saw in AZ.

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