Martian beasties must have had three sets of chompers!

It looks like wind-enhanced differential weathering of cementation. Some minerals, especially carbonates, exhibit a cone-shaped pattern as the cement precipitates in the pore spaces of the rock or sediment. A least in this piece of float, it looks like there were at least three times in which the precipitation stopped and started, nucleating on the previous episode.

Check out these terrestrial examples:

Cone-in-cone

Multiple cone-in-cone layers at Lyme Regis

from this paper:

Beef and cone-in-cone calcite fibrous cements associated with the end-Permian and end-Triassic mass extinctions: Reassessment of processes of formation

And what's that?
Detail in a sol 467 Mastcam-Z image, enlarged and enhanced

Click to view attachment

Great images guys

Here's a new handy dandy info page that recently appeared on the main mission page. Or you can access it directly on this link

It provides details on the cores and atmospheric samples acquired (so far) on the mission, some of the details are new (to me) including core length and rock type.

Click to view attachment

Those are Shiitake mushrooms.

Phil

Although I love Phil’s answer, I’m going to go with concretions. As with the previous cone/teeth structures, concretions and nodules are also cement phenomena. However, this time the pore fluid flow and geochemical gradients were such that the cement precipitated in spherical to mushroom shaped masses, rather than cones. I’d attribute the flat tops to some kind of permeability boundary that prevented upward cementation past it.

I make the differentiation between concretions and nodules at obvious compositional banding or layering (concretion) and more or less uniform masses (nodules), although there can also be differences in whether the cement is pore-filling (concretions) or displacive (nodules).

The broken one shows some very obvious compositional banding, with a lighter internal band, possibly a sulfate mineral.

ADMIN MODE: Seems like a good time to remind everyone, esp. our newer members, to carefully read the Rules and Guidelines section with particular attention to rule 1.3.

Pareidolia is entertaining, but if it's given any credence whatsoever it's tin-hat time. We don't do that here. Period.

Thanks.

And what about these two (p 16 and p.17, top)?


I doubt that NASA has other provider than Sheldahl for this stuff. Sheldahl has supported lots of projects for 20 years, including Mars-2020.


Perspective distortion is what matters most of all in this case.
You have chosen the right way to start with perforation holes: we know that they are ideal circles.
After that you calculated the diameter which found to be very close to the Sheldahl's standard which is 0.0450.

The last step is to choose between the patterns.It seems to me that there are only two to choose from: 045-0270 (page 16) and 045-0405 (page 17, top)

Source: the Red Book of Sheldahl.

Additional information: https://mashable.com/article/nasa-mars-rove...ds-debris-trash

I didn't calculate the diameter of the holes in the image because they are quite small, just about two pixels in diameter in the raw images (about 0.05 inch).
According to the anaglyph we are looking almost perpendicularly at the sheet. Apparently it has a 60° staggered perforation pattern.
The distance between neighboring holes is about 1.25 cm (about 0.49 inch), calculated by stereophotogrammetry.
The most similar type in the catalog is 045-0405, but its distance between neighboring holes is 0.405 inch = 1.0287 cm, which is 18 % less.
When scaling the drawing in the book so that 1 inch of the drawing is equal to 1 inch on the piece on Mars, as in the image below, the patterns do not match.
Even scaling and projecting the other patterns in the book by looking at them at an angle (not perpendicularly), I haven't found one that fits.

Click to view attachment

Back from terrestrial material to Martian geology with a sol 467 Mastcam-Z anaglyph (enlarged).
The protruding thing (concretion?) at 1400 pixels from the left and 240 pixels from the top is 11 mm in diameter.
The smaller round ones on the rock in the center of the image are about 2 mm in diameter.
The distance from the camera was about 2.9 m.

Click to view attachment

Gigapan - PERSEVERANCE 459
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

Gigapan - PERSEVERANCE 459
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

Can you tell me (i have photoshop) how you do that : turn the raw into those enhanced images that show different minerals / different colors ?

great work you do btw !!

here is a small ms ice panorama of the sol 470 watson images (laser stikes to the left)

The freshest abraded patch in Jezero (sol 471 SHERLOC-WATSON image)

Looks like the rock fractured during the abrasion process. I guess that may be considered a bonus as it shows the abraded surface and a freshly fractured surface, but maybe not perfect for PIXL?

A small light toned inclusion is also present.

Click to view attachment

Good point- I'm curious now, since the drill is an impact drill, perhaps future rovers would be able to split larger rocks using ancient technique of drilling a line of holes and then using a chisel to split the stone?

Would be interesting to see if it's possible to swap one of the spare drill bits for a splitting chisel and disable the 'rotate' function on the percussion drill to allow the rover to split rocks and reveal fresh faces.

A follow up thought- is the underside of these overhands also coated with dust? Curious whether the laser has been used to determine whether the underside of overhangs is also coated with dust? Question is whether the Martian dust has electrostatic properties which cause it to stick to all sides of the rocks, in contrast to simple 'air fall' where it coats the top surfaces?

My take on the WATSON mosaic of Bacon Strip, taken on sol 470 at 13:30 LMST.
Color corrected and correction of the artifacts due to dust on sensor.
It really reminds me the mudstones encountered by Curiosity at Pahrump Hills.

1. Sol 472 Supercam RMI mosaic with
2. Mastcam-Z left eye filter 0 context and
3. Mastcam-Z left eye multispectral filters 1 to 6 (visible to near infrared light) principal components image
See this post in the "Perseverance Imagery" thread

1 Click to view attachment . . 2 Click to view attachment . . 3 Click to view attachment

I get a distance to the sheet of around 10.6m (or 11.0m using the Bell etal toe-in angle rather than measuring it myself). That gives 1.36cm (or 1.42cm) for the neighbouring-hole separation (in the horizontal direction, which is closest to perpendicular to the line of sight). I don't know if this helps or not.

Looking carefully, there's some movement of the sheet between the two frames (so they can't've been exactly simultaneous) - that might affect these calculations a bit.

1. Sol 473 Supercam RMI mosaic of the abrasion patch
2. Sol 473 Supercam RMI mosaic in sol 472 Mastcam-Z left eye filter 0 context image
3. Sol 472 Mastcam-Z left eye multispectral filters 1 to 6 (visible to near infrared light) principal components
4. Sol 472 Mastcam-Z anaglyph

1 Click to view attachment . . 2 Click to view attachment . . 3 Click to view attachment . . 4 Click to view attachment

Via Paul (who is helping me a lot lately) comes a name for the sol 471 abrasion patch: Elkwallow Gap.

Phil

Sol 474 Drive...
A selection of the post drive tiled NavCam's from site 26/0850 (roughly assembled in MS-ICE)
Looks like a nice layered target in the arm workspace
Click to view attachment Click to view attachment Click to view attachment

Sol 474 Mastcam-Z
1. Left eye raw image (without black frame)
2. Left eye multispectral filters 1 to 6 (visible to near infrared light) principal components
3. Anaglyph

Click to view attachment Click to view attachment Click to view attachment

Wow, the principle component colour composite really does an excellent job of picking out the layering in that rock.

Paul's full set of images were used to make this circular view for sol 474 (I added one missing bit at the top of the hill).

Phil

Click to view attachment

A scenic Martian landscape with rover tracks in a small part of the sol 470 Mastcam-Z panorama looking south.
The horizontal ridge behind the nearest hill on the left is Séítah.
Around pixel coordinates 200 pixels from the left and 1575 from the top, the rover track of Sol 413 is clearly visible.
At pixel coordinates (520, 1610), the rover track of Sol 433 is very faintly visible.
What looks like a rover track at (100, 1500) is not a track, but a filled-in fracture with slightly raised edges.
Colors are enhanced.

Click to view attachment

Edit Corrected typo in sol number 470

This is a technique used since Spirit/Opportunity times to suggest compositional differences, although Tau has taken it to the next level.

--Bill

Panorama taken with Navcam Left on sol 474 at Hogwallow Flats, at 14:25 LMST. Really nice layered block near the rover. Does someone know if it has a name?



Speaking about that rock, I didn't have time yet to process the nice RMI mosaic taken on sol 436. Here it is, with the corresponding Mastcam-Z Left picture.

Sol 476 Sherloc Watson camera mosaic of this layered block near the rover.
Two blurred raw images at the top and bottom are not included.

Click to view attachment

Sol 476 SuperCam Remote Micro-Imager mosaic, most probably a detail of the layered block

Click to view attachment

"Does someone know if it has a name?"

Paul sent me this link:

https://sketchfab.com/3d-models/m2020-zcam-...288c3ec9de27d4d

It is called Betty's Rock.

Phil

Sol 477 - A Short drive away from Betty's Rock:
A selection of 2x2 and 2x1 tiled NavCam photomosaics roughly assembled in MS-ICE

Click to view attachment Click to view attachment Click to view attachment Click to view attachment Click to view attachment

Paul's images make this circular panorama for sol 477.

Phil

Click to view attachment

Fascinating distribution of angularity and of sorting.

Gigapan - PERSEVERANCE 466-471
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

1. Sol 477 SuperCam Remote Micro-Imager mosaic, same detail of Betty's rock as the sol 476 mosaic, but with different sun illumination
― Sol 476: sun elevation 47°, sun azimuth 190°, light incidence almost perpendicular to the rock surface
― Sol 477: sun elevation 29°, sun azimuth 132°, longer shadows
2. Sol 477 SuperCam RMI mosaic in Mastcam-Z context
3. Sol 477 Mastcam-Z left eye multispectral filters 1 to 6 principal components
4. Sol 477 Mastcam-Z anaglyph

Click to view attachment Click to view attachment Click to view attachment Click to view attachment

Sol 476 SuperCam RMI mosaic at the foot of Betty's rock in sol 474 Navcam context (same context for sol 477 mosaic)

Click to view attachment

Quite a soft piece of hardware on sol 477. Mastcam-Z right eye with enhanced colors.

Click to view attachment

Gigapan - PERSEVERANCE 477
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

Gigapan - PERSEVERANCE 458
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

One more artifact?

File details: ZR0_0477_0709275870_285EBY_N0260850ZCAM08498_1100LMJ Sol 477 09:48:27
2022-06-23 17:12:04.900

full size 1648 x 1200

Having a closer look at 'Oventop Mountain'

Animated GIF: 5 HazCam frames from sol 480

Click to view attachment

Source for target name LINK

"Betty's ribbon" on sol 477 with scale bar. The mesh size is about 2 mm.
1. Mastcam-Z right eye with scale. This piece of hardware wasn't there on sol 474, compare with this Navcam mosaic.
2. Anaglyph as usual. If you have a display with only sRGB color space, you will see a strong ghosting of the right (cyan) image in the left (red filter) eye.
This is due to the highly unsaturated green sRGB display pixels with a significant amount of red in their spectrum.
3. To reduce this ghosting, I tried the following:
- Decreased the maximum green histogram value from 255 to about 100 or less.
- Decreased the maximum red histogram value from 255 to about 200.
The result is a darker image with quite a purple cast, but the stereoscopic effect on sRGB displays is improved.

Click to view attachment Click to view attachment Click to view attachment

Links to raw images: left eye, right eye

Another name pops up: Skinner Ridge Rock.

https://mars.nasa.gov/mars2020/mission/stat...et-complicated/

Phil

Again, I am impressed with the sorting in this sediment view. It looks almost as if it was poured in. Is it a cataclysmic flow, such as a dam breaking? Or is it a turbidite from a collapsing delta front?

More clues from the outcrop!

--Bill

Gigapan - PERSEVERANCE 483
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

Gigapan - PERSEVERANCE 461
© NASA/JPL-Caltech/MSSS/ASU/NeV-T


Gigapan - PERSEVERANCE 464
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

Gigapan - PERSEVERANCE 464-2
© NASA/JPL-Caltech/MSSS/ASU/NeV-T

The layered cliff of "Rocky Top" on sol 483
1. Mastcam-Z left eye filter 0 raw image, black frame removed
2. Mastcam-Z left eye, principal components of multispectral filters 1 to 6
3. Anaglyph
4. Navcam context

Click to view attachment Click to view attachment Click to view attachment Click to view attachment

Sol 489 LMastcam-Z:
Click to view attachment

Sol 489 anaglyph:
Click to view attachment

Gigapan - PERSEVERANCE 484
© NASA/JPL-Caltech/MSSS/ASU/NeV-T