[X] My Assistant

[Guest_Sunspot_*]

Some pretty complex driving by the look of it:

http://qt.exploratorium.edu/mars/spirit/fo...E0P1214R0M1.JPG

Now this is odd:

http://qt.exploratorium.edu/mars/spirit/na...E0P0617R0M1.JPG

It looks like some of the rocks have slid down the dune

[glennwsmith]

I'm with you, gentlemen, this stuff DOES look like Meridiani, both up close and from a distance. I started a thread on this topic some weeks ago ("Spirit Hits Blueberries" -- you can find it via the "Search Forum" feature), and there was an initial flurry of interest -- but NASA/JPL/Cornell has not been very definitive about what they are finding. But maybe the stage is being set anew.

On the other hand, I have to keep reminding myself that the exposed surfaces we are seeing are the result of perhaps hundreds of millions of years of weathering via wind driven sand, dust devils, etc., so perhaps this TENDS to create a characteristic-looking surface regardless of the actual composition of the rock. I mean, imagine taking your beloved rock collection, sandblasting it for a couple of hours, and then trying to figure out what's what.

But darn, this Larry's Lookout stuff does have the same "ropey" appearance as the stuff Oppy has been seeing thougout!

Glenn

[CosmicRocker]

OK. I can appreciate that there are certain similarities among MI images taken of rocks by both rovers. But both rovers are commanded by people looking for layered rocks, and all of those rocks are presented to us microscopically as grayscale images.

The devil is in the details of the rock texture; the grain size/shape/orientation distributions. I think the rock compositions from spectral data is quite different also, but I don't have links to that at my fingertips. The MIs of the rocks from Eagle crater look very different to me from the latest MIs of Larry's outcrop.

There are so many images from Opportunity that one might compare these rocks to, but I chose a few from some press conferences and put them into a crude montage with the recent mosaic from Spirit.

[DEChengst]

The full six frame mosaic sol 489:

http://paranoid.dechengst.nl/mars/Larry%20Lookout.jpg

Color needs correction though and Photoshop drives me crazy with all the options Anyone willing to write a nice tutorial ?

[lyford]

Color needs correction though and Photoshop drives me crazy with all the options    Anyone willing to write a nice tutorial ? 

I have a better link in my bookmarks at home but this guy seems to have written a decent overview and there is a motherlode of tutorial links here. You can also get stuff on the adobe site, but it requires registration. I'll post more in the imagery forum later, if I remember
I have an "on again - off again-love-hate" relationship with photoshop....

[JES]

My first impression here was that I was looking at mud. The surface appears smoother, more reflective, perhaps finer grains collecting in a sheltered location?

[Bill Harris]

My first impression here was that I was looking at mud.

Mars does that to you.

I had a similar first impression with deposits of "hematite silt" from Oppy at Burns Cliff. Sometimes the windblown surfaces look quite water-borne.

We live in an aqueous environment and many times, past experience colors our perceptions. Things are not always as they seem.

--Bill

[CosmicRocker]

We received some MIs of the broken crust today. I made a small mosaic from them.



I have been wondering about these light patches seen in the pancams of the area. The fine grained, light areas in the MIs are certainly consistent with a major concentration of salts.

[Bill Harris]

Good mosaic.

I've see something like this locally. If a mine has pyritic material in the overburden, this material weathers into iron, sulfate (salts) and acid. This mineralized water saturates loose sand or porous sandstone, evaporates and leaves behind what is called a "sulfate bloom" on the surface.

Of added interest is the bright, overexposed "CCD bleed" in the top row of MI images used in the mosaic. This suggests to me a fresh, reflective crystal face (well, "object"; crystal has a new-age loaded meaning) on the surface.

--Bill

[CosmicRocker]

Bill:

I have seen similar things as well in sulfide rich sediments that were exposed to oxidation. I see the similarity.

I also noticed that CCD bleed, but didn't stop to think about it. You could very well be correct. I found another MI of the same area without the flare, but it was somewhat out of focus. There was still an indistinct bright area at that same location. Scanning other images of this stuff, I can see some grains that suggest a cubic or rhombic outline, and one or two of them that have what might be a crystal face that is saturated in luminosity.

It appears as if they have backed away from this site without using any of the other instruments on the arm. I would have liked to have seen more of an investigation, but perhaps they already know what they were looking at.

[dilo]

Here a super resolution outcrop image (sum of 8 PanCam frames from Sol494):

[Bill Harris]

The specular reflection was so unusual on dusty, wind-eroded Mars that it was _very_ noticable. Hopefully, someone in the back room noticed it too and got more MIs.

--Bill

[CosmicRocker]

Steve Squyres has a new update today, with a lot of discussion of these rocks.

http://athena1.cornell.edu/news/mubss/

I was actually thinking of posting a message here today arguing for an impact origin of these rocks, but Steve says they favor a volcaniclastic origin. He also has some interesting discussion of the distribution of alteration they have observed. Apparently they have seen some pretty significant alteration, even at the top of the section.

[wyogold]

Bill:

I have seen similar things as well in sulfide rich sediments that were exposed to oxidation.  I see the similarity.

I also noticed that CCD bleed, but didn't stop to think about it.  You could very well be correct.  I found another MI of the same area without the flare, but it was somewhat out of focus.  There was still an indistinct bright area at that same location.  Scanning other images of this stuff, I can see some grains that suggest a cubic or rhombic outline, and one or two of them that have what might be a crystal face that is saturated in luminosity.

It appears as if they have backed away from this site without using any of the other instruments on the arm.  I would have liked to have seen more of an investigation, but perhaps they already know what they were looking at.

Oh man, would this be a micromounters wet dream or what.. ...........minerals in crystal form from Mars.....oh yah....
so care to guess what mineral it is composed of?

Scott

[CosmicRocker]

Oh man, would this be a micromounters wet dream or what.. ...........minerals in crystal form from Mars.....oh yah....
so care to guess what mineral it is composed of?

Scott

Oh, yeah. I wouldn't mind having a few of those micromounts...one for my collection, and the others for sale on Ebay.

If that really was a crystal gleaming in the sunlight, I'd hesitate to guess what it was. There are so many possibilities. Small crystals are relatively common in soils and sediments on Earth, and I see no reason the same shouldn't be true on Mars. I'm actually somewhat surprized we haven't seen more examples of this.

[CosmicRocker]

I noticed an interesting pancam sequence captured on sols 497-498, and managed to convince Autostitch to combine all 28 images into this panorama.



It's interesting to see the crisscrossing pattern of tracks here, and further down the hill. It gives one a sense of how carefully they are investigating the rocks in this area. Like a good field geologist, Spirit's been all over these outcrops. I had to shrink the original 33 MB image down to 1 MB to post this, but I don't think it lost too much detail.