The Top of Vera Rubin Ridge Part 1, Site 66-67, sol 1812-1943, 11 Sep 2017-23 Jan 2018 Options

[PaulH51]

Does anyone know why MARDI was taking so many images during Sol 1910?

From the 1909-1910 mission update: During the drive (Sol 1910) we'll take a bunch of MARDI images to document the terrain beneath the rover.

I guess they will make a fine time lapse movie once properly processed

[nprev]

And so they have.

[nprev]

Rather fascinating ChemCam image from sol 1921. Are these crystals, presumably (impure) gypsum or some sulfate? It almost looks like staurolite, but that would be a highly unexpected complex mineral. Hopefully there will be an analysis soon.

[PaulH51]

Rather fascinating ChemCam image from sol 1921. Are these crystals, presumably (impure) gypsum or some sulfate? It almost looks like staurolite, but that would be a highly unexpected complex mineral. Hopefully there will be an analysis soon.

Here is the R-MastCam context image:

link to the full size version. Looks like there are even thumbnails of a set of MAHLI images of the same target

[serpens]

There are a few more examples on the rock just to the left.

Attached thumbnail(s)

 

[PaulH51]

There are a few more examples on the rock just to the left.

Maybe others? Here is an RMI from 1922 that looks like it has captured what appears to a few more of these small 'crystalline structures'? Looking forward to seeing those MAHLI full frames...

[Gerald]

There are a few more examples on the rock just to the left.

With this context, I'm almost inclined to consider weathering remnants of an overlying layer as a possible origin, possibly some fracture fill.
In this case, I'm wondering, whether the geometry is pointing towards remnants of filled desiccation cracks. Could it be an iron-rich precipitate?
There are some (other?) presumed weathering remnants in the same Sol 1921 MR image, which look darker and more saturated than the underlying layers. This might indicate towards a hematite, hence iron rich, and mostly weathered overlying layer.

[PaulH51]

With this context, I'm almost inclined to consider weathering remnants of an overlying layer as a possible origin....

The full frame MAHLI's are now available...
I have roughly assembled this red/cyan anaglyph from a pair of the images with approximately the same focus count. Others will be able to do a much better job, but evenin this rough version I can see the feature some has some depth, thus may fit with Gerald's observation re weathered remnants of an overlying layer.

[serpens]

Fracture fill remnants feels right and they have the appearance of scattering rather than eroding out in situ. I wonder whether the two "host" rocks were once a single piece of float that fractured, separating along the plane of the fracture fill. Both "host" rocks seem to have areas of lighter colour which may, or may not be significant. One thing is certain, there are going to be some very interesting papers at the next LSPC.

[elakdawalla]

From the 1909-1910 mission update: During the drive (Sol 1910) we'll take a bunch of MARDI images to document the terrain beneath the rover.

I guess they will make a fine time lapse movie once properly processed

And so they have.

The term for this kind of observations is "sidewalk mode." From my book:

Sidewalk mode. MARDI can take movies during drives, acquiring mosaics along drive paths. In sidewalk mode, MARDI takes an image every 3 seconds, but only saves the image if onboard software determines that the new image is significantly different from the previous one. The saved images have more than 75% overlap. Returning every third image to Earth allows the construction of a mosaic, but if all images are returned, the team can generate a digital elevation model in addition to the mosaic.

[mcaplinger]

The term for this kind of observations is "sidewalk mode."

Another bit of trivia: this is the only part of the DEA software that was written after launch, and has only been used for the MARDI DEA. The other cameras are still running the same version of the software they were loaded with back in 2011.

[PaulH51]

1923 drive: here's a crop of what I could stitch with the L-NavCams, Damia or Jan will hopefully tackle the full pan, but this rough version may assist in narrowing down the location until they can post
EDIT Midnight Planets is having issues, but Joe's page has elements that are working again, his page suggest the drive was ~12m ~ESE

[serpens]

They got really up close and personal with this image and the broken ends do look metallic. Some segments can be seen bonded to the rock and given that this area is the hematite ridge it seems likely that this is indeed iron oxide. It is almost as if Mars has its own version of banded iron formation based on fracture fill. On balance this seems more likely for oxygenated water infiltrating the saturated zone from a disconnected stream than groundwater flowing to the surface.

Attached thumbnail(s)

 

[Gerald]

Hopefully, they'll be able to collect some APXS data, at least, in order to see whether it's actually some kind of iron mineral, or some SiO2 modification, instead. The latter could fracture in a conchoidal way, and then appear specular, too.

[Art Martin]

A quick and dirty stereo anaglyph of the Mount Sharp view on 1923

Sol 1923 Mount Sharp Navcam Stereo