Finishing work in and around Seitah, sols 238-378 Options

[Phil Stooke]

It's time to start a new thread - this will cover the remaining work in Seitah and the drive back to the landing site.

Phil

[Phil Stooke]

OK, a drive up to the outcrop on sol 238. Here is a circular view of the new location.

Phil

[tau]

An outcrop of compact, layered rock with overlying vesicular rock fragments on sol 238.
Mastcam-Z left eye filter 0 (RGB), colors enhanced.

[Bill Harris]

Tau, this stratigraphy is getting interesting.
Time to backtrack and try to intuit the bedding orientation.

--Bill

[serpens]

Perseverance had a pretty fair tilt when this was taken and these are probably as horizontal as the precious ridge.

[Phil Stooke]

Sol 239, another drive... another circular panorama.

Phil

[serpens]

An outcrop of compact, layered rock with overlying vesicular rock fragments on sol 238.

To me this looks more like honeycomb weathering of basaltic sandstone rather than vesicular basalt tau, but I stand to be corrected.

[tau]

If the term "vesicular" implies a specific type of rock or origin of the rock, then I would rather refer to it as "spongeous appearance".
I would not rule out weathering as the reason of the small holes/cavities.

[tau]

Tau, this stratigraphy is getting interesting.
Time to backtrack and try to intuit the bedding orientation.

Perseverance had a pretty fair tilt when this was taken and these are probably as horizontal as the precious ridge.

As to the bedding orientation, here is a sol 236 Navcam image with the sol 238 Mastcam-Z image as inset. If there is any tilt of the rover, it seems to be rather small.
Navcam and Mastcam-Z are looking east-northeast. The layers are dipping to the right, i.e., towards the Artuby ridge.
This is consistent with the Rimfax results in the screenshot below, which is from a presentation by Kathryn Stack Morgan. Thanks to cIclops for the link to this very interesting video!
The part about Rimfax and Séítah layering begins after 21 minutes. Here is a direct link to this part.

The field of view of the sol 238 Mastcam-Z image and the position of Perseverance on sol 239 are marked in the upper right section of a helicopter photo from sol 174.



EDIT: Corrected the compass direction that the Navcam and Mastcam-Z looked at. I had accidentaly typed west where I meant east. The correct direction is east-nordeast.

[Bill Harris]

I haven't had the chance to look at that video presentation yet.
The RIMFAX data fairly well corresponds to my general observations. In a general sense, the "beds are essentially flat-lying with a gentle regional dip to the southwest". Artuby ridge is stratigraphically the high point of this section of the traverse and we are headed along stratigraphically lower units. And Artuby is the youngest unit, and we are traversing along increasingly older units.

Nice presentation of yours.

--Bill

[serpens]

Indeed, good one tau. The Rimfax trace doesn't show any real change in the angle of dip despite a 90 degree turn across the terrain, not that I have any skill whatsoever in interpreting such.

The reason I suspected an element of tilt was due to this Sol 238 Navcam image.

Attached thumbnail(s)

 

[Phil Stooke]

That picture was taken at the sol 238 location, but Tau's image was from the sol 237 location, before the drive on sol 238.

Phil

[PaulH51]

4x4 Navcam tile of Perseverance's post-drive workspace on sol 239.
Very roughly assembled and reduced to fit upload limits

[tau]

Perseverance had a pretty fair tilt when this was taken and these are probably as horizontal as the precious ridge.

The tilt of the previously shown sol 238 Mastcam-Z picture can be estimated with the projection of the images onto a sphere provided online by marslife.org.
The mast was tilted about 4° to the left (that's more than I presumed from the Navcam photos). When we apply the tilt to the picture, the layers are still tilted to the right (towards Artuby ridge) with an angle of about 7° to 8°.
This is in accordance with the Rimfax results where we have a dip angle of about 12° towards Artuby ridge.

[Bill Harris]

This site you noted, https://marslife.org/ , looks interesting and potentially useful. Let me dig around and find documentation on the site.

--Bill

[serpens]

The dipping structure in the Rimfax trace seems to disappear at the third position Tau and it would be interesting to see subsequent results to determine if similar structure re-appears. The trace presentation seems to be truncated in the X axis which accentuates the angle of dip which if the trace were extended to agree with the 15 metre depth would be around 7 degrees.

[tau]

The Rimfax diagram has two small marks for sol 201 and sol 202.
In the Hirise map, the positions of sol 201 and sol 202 can be connected by a stright line ("as the crow flies") with a linear distance of about 43 m.
This line is almost perpendicular to Artuby ridge. The ridge can be assumed to represent a strike line of the layers.
When the Rimfax diagram between sol 201 and sol 202 is stretched horizontally according to the vertical scale, we get a dip angle of about 11° to 12°.

[tau]

Sol 242 SuperCam Remote Micro Imager with double context.
Grain-size measurement by stereoscopy gives an average grain diameter of about 1.3 mm

[PaulH51]

Roughly processed sol 248 end-of-drive 4 tile Navcam. The site index incremented which could indicate we are at, or very close to the next sample site.

[Phil Stooke]

Yes, a move, but really just a turn in place (possibly involving a drive downslope, a turn and back upslope, but I only see the end result).

Phil

[Bill Harris]

Roughly processed sol 248 end-of-drive 4 tile Navcam. The site index incremented which could indicate we are at, or very close to the next sample site.

Plenty of interesting contacts here. Especially that (apparently) loose rock at the top with the dark basaltic (?) unit on top of the grey clastic (?) unit on top of the in-place units.

--Bill

[tau]

Kodiak behind Séítah as seen by the SuperCam Remote Micro-Imager on Sol 248

[Phil Stooke]

That's a beautiful image of Kodiak. Thanks!

Here is a circular panorama for the current position.

Phil

[Phil Stooke]

Paul: "The site index incremented which could indicate we are at, or very close to the next sample site."

I was asked about site numbering, and i don't have specific information about Persererance, but this is a document for Curiosity which discusses sites.

 MSL_Coordinate_Frames_Mar5_2013.pdf ( 343.63K ) Number of downloads: 373



I expect the situation is the same for Perseverance. A new site number doesn't really suggest sampling is about to happen, though I expect it is.

Phil

[djellison]

The site incrementing is usually because the propagated error in attitude knowledge has reached a certain limit. It's usually based on cumulative IMU on time.

[tau]

Sol 247 SuperCam RMI with Mastcam-Z context and sol 147 Helicopter color camera context

[tau]

Sol 252 SuperCam RMI with Mastcam-Z and Navcam context

[PaulH51]

Sol 253: Processed R-Navcam (4-tiles) assembled in MS-ICE shows the latest abrasion target 'Brac?'

[tau]

A sol 253 Sherloc Watson camera image with enhanced colors and an anaglyph of the abrasion target.
Could that small white triangle above the center of the abraded area be a lost part of the abrasion tool?

[tau]

Sol 253 SuperCam RMI with Mastcam-Z and Navcam context

[PaulH51]

Mars Helicopter - November 6, 2021 (Sol 254) Flight 15 NavCam - 12:06 local time

[charborob]

Sol 254 LMastcam-Z:

[tau]

The sol 253 abrasion target in sol 255 Mastcam-Z images
1. Raw image left eye filter 0 (visible RGB)
2. Left eye filters 0 to 6 multispectral principal components
3. Right eye filter 0 (RGB) and infrared filters 1 to 6 multispectral principal components

1 . . 2 . . 3

[tau]

The abraded surface in a combination of sol 257 images with SHERLOC Autofocus and Context Imager for detail and SHERLOC WATSON camera for enhanced color.
Do I see concentric zoning and lamellae in some crystals (I do not mean the visible effect of the abrading tool hammering), or are these just image artifacts or imagination ?

[Bill Harris]

We do see zoning as well as lamellae in these mineral grains. I'm thinking that the zonation is due to weathering in a wet and oxygenated environment. These rocks are covered with a weathering crust and this abraded area is just beneath that zone.

--Bill

[tau]

Sol 256 SuperCam Remote Micro Imager with Mastcam-Z context and anaglyph

[Bill Harris]

Percy hasn't covered much distance since leaving the Artuby ridge. But the Micro Imager shows consistent grain size, sorting, and angularity in several images. More important than the linear surface distance is the stratigraphic interval, which covers time as well as space. We don't know the deposition rates yet, so this time interval could be years, tens, or hundreds or thousands.

--Bill

[Phil Stooke]

Since this is Mars, it could be hundreds of millions of years.

Phil

[tau]

Sol 248 Mastcam-Z. Kodiak with enhanced colors and as anaglyph.
The stereoscopic effect is quite weak because of the large distances.
The visible distant part of Séítah is about 1 km away, Kodiak 2 km, and the inner crater wall about 7 km and more.

[PaulH51]

Latest sample from Jezero imaged in the rover's coring bit.
November 15, 2021 (Sol 262)
Edit: Added L-Navcam of the hole
Edit#2: roughly assembled raw 4-tile L-Navcam (MS-ICE)
All jpg'ed to reduce server impact

[neo56]

My take on the 4-tile NavCam Left mosaic.

[PaulH51]

Sol 262 CacheCam shows the core is in at least two sections. The 2nd (later) image provides us a with a side-on view of the upper section of the core closest to the camera.

I'm assuming the upper section of the core rotated after the static probe was used at the Volume station to measure the size of the sample, and to ensure there was room to fit the seal.

I'm sure geologists will enjoy this bonus side-on view of the split core and its grain structure.

[tau]

Sol 255 SuperCam Remote Micro Imager with context images (2 Mastcam-Z sol 255, 1 Navcam sol 253), ordered by decreasing focal length

[vikingmars]

Sol 255 SuperCam Remote Micro Imager with context images (2 Mastcam-Z sol 255, 1 Navcam sol 253), ordered by decreasing focal length

Thanks a lot Tau for this superb work of yours

[tau]

Sol 265 SuperCam Remote Micro Imager with context images Mastcam-Z sol 241 and Navcam sol 248.
It took me a while to find appropriate context images.

[john_s]

Looks like there may be some ripple structures preserved in the rock in that image.

John

[tdemko]

Looks like there may be some ripple structures preserved in the rock in that image.

I see what you are talking about, at some of the bed boundaries. There is also a fallen piece that has a bedding plane exposed with what could be small 3D dunes or ripples (can't quite determine the scale). They both are not pleasingly preserved, at least from here, so we'll have to wait and see. We've been seeing distinct bed boundaries for a while, in several places along the traverse, at several stratigraphic intervals. None of them looked completely planar, but there were no obvious ripple forms either, let alone cross-stratification within the beds. After finally determining that the grain size was in the medium-coarse to granule range, that's not surprising. Maybe the grain size is smaller in these outcrops, and ripples and dunes could have formed during the flows.

[xflare]

Looks like there may be some ripple structures preserved in the rock in that image.

John

Which image are you referring to?

[john_s]

This post. Specifically the wavy bedding planes left of center, and the funky-looking slab surface on the slope just lower right of center.

John

[tau]

Here is a detail of the image mentioned above. Those two rocks caught my attention, too.

[tau]

I see what you are talking about, at some of the bed boundaries. There is also a fallen piece that has a bedding plane exposed with what could be small 3D dunes or ripples (can't quite determine the scale). . . .

Regarding the scale, here is a sol 265 Mastcam-Z context panorama for the sol 265 SuperCam detail image (bluish rectangle to the right), and a HiRISE map of the panorama's field of view.
The target taken by the SuperCam is circled on the map. It is almost exactly 200 m away from the rover.
With some calculations it came out that the visible distance between the suspected ripple crests is about 9 to 10 cm in the SuperCam detail image (see previous post).

[Phil Stooke]

A second drill hole and sample just done at Brac.
https://mars.nasa.gov/mars2020-raw-images/p..._0LLJ01_800.jpg

Phil

[neo56]

Here is a picture of the second drill hole in Brac taken on sol 271.

[Phil Stooke]

I have collected and labelled images of the various sampling (and related activities) sites with the names as I know them so far. I don't yet have a name for the most recent sample hole. All images are oriented roughly north-up, not in raw image orientation.

Phil

[vikingmars]

Sol 265 partial pan and also in 3D. Enjoy

[vikingmars]

Because the distances between the foreground and background are big, take some time to let your eyes adapt

[PaulH51]

Sol 271: CacheCam 2-tile fusion stitch of sample number 5 in its tube prior to sealing, roughly assembled in MS-ICE (unprocessed other than the stitch)

[vikingmars]

Sol 248 of Perseverance's mission : more spectacular rocks to be seen... and also in 3D. Enjoy

[tau]

Sol 274 SuperCam Remote Micro Imager with sol 274 and sol 265 Mastcam-Z context

[charborob]

Sol 275 Lmastcam-Z:

[vikingmars]

Sol 275 Lmastcam-Z:

What a nice mosaic! Thanks Robert to share this work with us

[vikingmars]

Sol 239 : here is one of the nicest views with gorgeous piles of rocks taken during the whole mission !
Also in 3D. Enjoy

[Sean]

Here is my hasty effort ( avoid the extended sky! ) for Sol 275 MZR along with a 4k video on Youtube

[Phil Stooke]

Very nice, Sean. Thanks!

Sol 278 - we just had a small move uphill, so the rover is now above Brac - behind it from the previous perspective.

Phil

[Phil Stooke]

A quick circular panorama for sol 278.

Phil

[tau]

Sol 280 SuperCam Remote Micro Imager with sol 275 Mastcam-Z context showing the planned entrance to the delta remnants near a location on the crater floor called "Three Forks".
Will there be a continuation with some SuperCam RMI images on the right?



Edit: For extended context, check out the center of Sean's beautiful panorama in post #63.
Second edit: "Planned entrance" refers to this image in the JPL Photojournal from January 2021, that was before landing. Plans may have changed meanwhile.

[Phil Stooke]

Sol 280, a circular view with lots of nice sandy ripples. This looks like the start of the return journey so it will lead to a new map.

Phil

[Phil Stooke]

Another drive on sol 281 - here is a circular version of a panorama.

Phil

[tau]

The planned entrance to the delta remnants in sol 280 Mastcam-Z images.
1. Raw image
2. Contrast enhanced
3. With simulated haze to emphasize the relief and the landscape units, and with distances from the rover position on sol 280
4. Left eye filters 1 to 6 multispectral principal components

1 . . 2 . . 3 . . 4

For SuperCam details see also post #66.
Edit: "Planned entrance" refers to this image in the JPL Photojournal from January 2021, that was before landing. Plans may have changed meanwhile.

[Phil Stooke]

Sol 283, we had a small move, a few m only, to the NE plus a rotation.

Phil

EDIT: here's a circular panorama for sol 283.

[PDP8E]

SOL 275 9:15 AM
This is a part of the morning PAN (Kodiak) -- 4 image stitch
Adaptive-Equalization

[tau]

Layered outcrops in Séítah with Kodiak and the crater wall in the background on sol 282
1. Mastcam-Z right eye filter 0 (RGB), colors enhanced by principal components analysis
2. Anaglyph with impressive stereo effects (best seen on displays with wide gamut or extended color space)

1 . . 2

[PDP8E]

SOL 283
We have clouds ...

[vikingmars]

Sol 284: nice afternoon clouds. Enjoy

[vikingmars]

Sol 279.
I could not resist building this small panorama that shows such a romantic view with its scattered rock piles seen at late afternoon: this is the 'Mars' dreamed by Ray Bradbury.
Also in 3D. Enjoy

[vikingmars]

(cont.)

[Phil Stooke]

Here is a circular panorama after the sol 285 drive. The next drive might just get out of Seitah, or to the bottom of the last slope.

Phil

[PaulH51]

Welcome to site 9...
Sol 286: 4-tile Navcam (roughly assembled in MS-ICE)
EDIT: Looks like a drive SSW by about 8 meters

[PDP8E]

Sol 285 -- 2:28 PM
Early afternoon clouds over the crater rim -- deltas in the foreground

[PaulH51]

Looks like we may not be leaving Seitah as soon as I expected?
Sol 288 Hazcam (jpeg'd to save space)
Drill press? or maybe abrasion preparation?
Watch this space

[charborob]

Sol 288 LMastcam-Z:

[PDP8E]

Here is a subset of SOL88 Lmastcam-Z

[Bill Harris]

Back at Artuby.

[tau]

SuperCam Remote Micro Imager with Mastcam-Z and Navcam context on sol 286 at the edge of Séítah.
Stereophotometry gives an average grain diameter of about 1.3 mm

[tau]

A pretty fragile structure on sol 286.
Mastcam-Z anaglyph and left eye filter 0 (RGB) with enhanced colors.

[Phil Stooke]

Circular panorama for sol 286.

Phil

[PDP8E]

Here is a local ridge PAN on SOL 289 -- 4:10 PM

[charborob]

Sol 290 LMastcam-Z:

[tau]

Many interesting panoramas in these days and sols.

Here comes sol 290 SuperCam Remote Micro Imager with context (Mastcam-Z and Navcam sol 288, HiRISE) and Mastcam-Z anaglyph.
The bright pebble in the SuperCam image to the right of center, enclosed between two layers, has a horizontal size of about 13 mm.
The distance from the rover to the SuperCam target is 18 m.

[tau]

Sol 290 Mastcam-Z
1. Left eye filter 0 (RGB) raw image
2. Left eye filters 1 to 6 multispectral principal components
3. Right eye filters 0 to 6 multispectral principal components
The small sharp-edged fragments with a slightly purple tint in the foreground are probably made of a different material than the other rocks in the image.

[vikingmars]

The next poster to be seen on the wall of my office. Enjoy

[Cherurbino]

With what instrument was this test performed? (sol 291)



(full_res: https://mars.nasa.gov/mars2020-raw-images/p...4_0000LMJ01.png)

Attached thumbnail(s)

 

[Floyd]

Deliberate wheel scrape? There seem to be parallel scratches that a wheel scrape would make. Just a guess.

[tau]

At first I had also thought of wheel scratches. But the lack of wheel marks around the rock and the timing looks like an abrasion attempt.
An uneven surface with rounded granules apparently prevented successful abrasion. Some of the granules were crushed.




Links to the original raw images:
Mastcam-Z
Front Right Hazard Avoidance Camera A
SHERLOC WATSON camera

Edit: Corrected annotation and raw image link to Front Right Hazard Avoidance Camera A

[tau]

Sol 291 SHERLOC WATSON camera
A very elongated crystal (length/width ratio 12:1 or more), or something else?

[PDP8E]

SOL 289
My DD detector couldn't find any DDs in this sequence but it kept lighting up the sky - Clouds
2:53 PM to 3:14 PM (~21 minutes)
Chopped out the foreground
(faint) Clouds in motion:

[Cherurbino]

Meanwhile on December 15 NASA published unusually large set of materials in the 'News' section (six or more?) among which the most encouraging (IMHO) is this one named «NASA’s Perseverance Mars Rover Makes Surprising Discoveries». The article tells about the unexpected results of the 2-day intensive usage of RIMFAX at the entry of Seitah-S, just after crossing Artuby ridge on sol 200.

[tau]

. . . An uneven surface with rounded granules apparently prevented successful abrasion. Some of the granules were crushed. . . .

I was wrong with the crushed rounded granules. Obviously, these are fragments of the partially abraded very uneven surface of the rock, as an animated comparison before (sol 287) and after abrasion attempt (sol 291) shows.

[tau]

Sol 292 SHERLOC WATSON camera image (with enhanced colors) of a successful abrasion

[Bill Harris]

Phenocrysts!

https://www.cnn.com/2021/12/15/world/persev...-scn/index.html