Traverse to the Delta, sols 379-414, 15 Mar 2022- 21 Apr 2022 Options

[StargazeInWonder]

On the third image of Sean's post #39, the MZL_00388 panorama, there is a dark downslope flow material that looks a little like the gullies seen elsewhere. Perhaps these are much smaller, different, and just dust, but they are eye-catching. I don't think we've seen anything like this on Mars before from the ground.

[tau]

Sol 395 Mastcam-Z panorama with enhanced colors
The prominent cliff behind the rounded hill on the left is part of the delta.
So-called "northern fan deposits" are visible behind this cliff in the distance and to the right.

[Sean]

Preliminary shots from 395...

[tau]

Sol 395 Mastcam-Z looking east. Colors enhanced.
Port Angeles crater with layered outcrops on the inner slope.
The hills in the background are probably heavily eroded remnants of delta sediments.
Curvilinear layers are faintly visible on the slopes. Distance from the rover about 2.4 to 3 km.
The rock on the far left behind the hillside is a small variant of Kodiak hill, distance about 3.3 km.



Edit: Corrected the name of the crater

[tau]

Sol 395 anaglyph Mastcam-Z looking north

[vikingmars]

Sol 395 Mastcam-Z panorama with enhanced colors
The prominent cliff behind the rounded hill on the left is part of the delta.
So-called "northern fan deposits" are visible behind this cliff in the distance and to the right.

Very nice Tau

[tau]

Crater Port Angeles and Perseverance's tracks on sol 395 in stereo.
Best seen on displays with extended color space, wide gamut, AdobeRGB, or similar.
Ghosting or double images in the left eye (red filter) are unavoidable on sRGB displays.
The ghosting can be reduced by attenuating the green channel of the image, but then the image takes on a distracting purple tint.



Edit: Corrected the name of the crater

[xflare]

Another safe mode event??

[Phil Stooke]

Was the first one a safe mode? I hadn't heard anything about it. That would certainly be a reasonable explanation.

Phil

[Phil Stooke]

We just got several sols worth of images dumped on the server (thanks a lot Percy, I'm supposed to be working...).

Phil

[tau]

Sol 397 SuperCam Remote Micro-Imager mosaic no. 1 of delta sediments

[StargazeInWonder]

This SuperCam image, like details seen in the Post #39 panorama, shows the downslope flow of what might be a very fine dark dust that seems to originate from the face of the sedimentary layers. For it to overlay the usually ubiquitous brighter airborne dust would seem to indicate a substantial rate of new generation of whatever this dark stuff is. It, again, is reminiscent of what on much larger scales is seen in gullies which raises, again, the question of whether dark downslope flow is purely dust, or is there some H2O involved? Otherwise, it seems like some of the darker rock is eroding at a considerable rate in the present time. Otherwise, how could these dark trails not be covered with the baseline of brighter martian dust?

[tau]

Sol 397 SuperCam Remote Micro-Imager mosaic no. 2 of delta sediments

[mcaplinger]

Was the first one a safe mode? I hadn't heard anything about it. That would certainly be a reasonable explanation.

I believe Steve Ruff mentioned that in his most recent episode on Youtube. https://www.youtube.com/c/MarsGuy

Most people aren't authorized to discuss mission ops publicly because of project rules. In general, I think there would be a press release about a major outage or problem, but a minor one might well go unmentioned.

[Saturns Moon Tit...]

Thank you for the image, Tau. This particular image got my inner sedimentologist very excited, I'm sure it'll be the subject of several publications. I made a quick annotated version showing my preliminary interpretations.

Essentially I interpret this conglomerate deposit as a high energy flash flood deposit during an interval when lake levels lowered. The sheer size of the clasts transported (the largest is ~1m across, based on an LPSC abstract which studied lower res images of this same outcrop) requires a powerful flood to transport them, and the high degree of rounding of the clasts suggests they were transported quite some distance. Given that the clasts appear to be several different colours and so lithologies, this agrees with the long distance idea. I suspect they were sourced from outside the crater, and so potentially have travelled many km, and could represent basement materials. The deposit itself is not sheet-like and continuous but instead appears channelised and pinches out, so perhaps the flood followed a pre-existing (dried up?) river channel. The return of delta sandstones above it might indicate a rise in lake level. There are curious discontinuous patches of bright angular 'bits' embedded with this sandstone & I'm not sure what they are, marked in pink. The presence of eroded-out rounded boulders stratigraphically higher, towards the delta top, indicates there was at least one other flash flood deposit later on, so this was not an isolated event.

Hopefully there are conglomerate deposits where the rover will be traversing when it climbs up and onto the delta in a few weeks. Because if I'm right, and these rounded clasts represent distant lithologies from the Jezero watershed, then they could be ancient (Noachian) basement rocks which would be a very high priority for sample return.