Sol 405 - the afternoon panorama in circular form. Good driving terrain!

Phil

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Good point Doug. Well noted.
So, we hope that we could get good pictures of the backshell and its parachute from the helicopter Ingenuity which is not far away from them
Those could be even more spectacular ! "Dare Mighty Things"

Sol 405 Navcam panoramic is just great. The base of the delta is very close now !

97 new Mastcam-Z raw images of the delta from sol 306 just arrived.
Here are three of them, specially selected for the "inner sedimentologist" of Saturns Moon Titan, in a processed version.
A note for new visitors: the blue color of some of the stones in the images is due to color enhancement. In reality they are more gray or brownish gray.

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last image looks igneous

Thank you for processing these images tau they're great!

I should say that I'm not a sedimentologist, I'm more trained in analysis of orbital imagery, but I did attend the rover sessions at LPSC this year and I'll be helping with Perseverance operations when I start my PhD this fall. At LPSC the expectation, from long-distance imagery of these very same outcrops, was that they would be pro-delta (lakebed, deep water) mudstones. This was on the basis of their horizontal bedding and position at the very base of the delta (unlike the delta scarp stuff above which is often steeply inclined and represents delta front sandstones).

I actually think these new images contradict that hypothesis. The first image shows a conglomerate slab including at least two boulder-sized clasts that resembles what we saw a few days ago, however it's not clear this outcrop is in-situ and it might have slid down from higher up. The second image however is clearly in-situ and I believe it does not show a prodelta deposit but rather a fluvial or delta front deposit. This is because there is large-scale truncation surfaces and seem to be pebble or cobble-sized clasts embedded within it, all of which is consistent with sandstone rather than mudstone. However some of the horizontally laminated intervals might contain muds and silts interbedded with sands. The third image is the most enigmatic and scientifically interesting. There is a weird large undulation, and I'm really not sure what it could be. But since there's no folding on Mars this must be some kind of sedimentary bedform. To the left, the inclination of the bedding appears alarmingly steep, but I suspect this is an illusion due to foreshortening/perspective. There is also an unusual lithology here, it could be a massive (internally structure-less) sandstone bed or perhaps the elusive mudstones, just laminated so thinly the resolution is too poor to pick it out.

This has implications for the future of the mission. The idea that Perseverance would be able to access prodelta mudstones is kind of the whole reason the rover was sent to Jezero, because those clay-rich deposits have high potential for preserving biosignatures. But in my opinion, at this distance, these outcrops look to still be predominantly the sandy delta front, even though they're near the base of the delta scarp. Perseverance is not going to be approaching these outcrops though, so I guess that's not super relevant. Hopefully, at the base of the 'three forks' area, Perseverance will encounter the muddy prodelta deposit that the astrobiologists are so eager to drill.

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Panorama taken with Mastcam-Z Left on sol 406 at 9:30 am LMST. It's a pleasure to zoom in to dive into the wealth of details!

The curving structure in Tau's third image might represent deformation of the soft sediments during slumping. Very cool to see these things.

Phil

My guess, only looking at this image, is that the fold could be some kind of turbidite/slumping. These processes are able to create "folds" in active delta enviroments.

Looking at the context of this deposit in Neo56's cool panorama it does appear to be localized laterally, extending back into the delta. Possibly a channelised deposit of mudstone rich sediment that had been eroded and transported from a pre-existing deposit?

Incredible panorama, Mastcam-Z really is a wonderful instrument. I encourage everyone to download the high resolution version and zoom around. There's way too much interesting stuff here for me to bother annotating (I think an entire PhD thesis could be written using this panorama alone) however I found a couple of interesting things that are at the edges of the panorama, away from the 'main action', that you might not have noticed:

at the far-left of the panorama, on a very distant part of the delta scarp, there's a textbook-tier erosional unconformity. Since the rover is driving in this general direction the image resolution of this feature should improve a lot over the coming weeks.

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at the upper right, there's an oblique view of the boulder conglomerate capping unit that the rover was parallel with a few days ago. This along-strike perspective reveals that, like the delta front sandstones below it, the conglomerate deposit is dipping pretty steeply southwards. This strongly suggests that the lake level dropped significantly (perhaps entirely drying out), because the flash flood carrying all these boulders is cascading down the slope of the delta front. It would have been a spectacular and dramatic sight - a waterfall carrying meter-sized boulders. Jezero Crater was home to some violent floods far more powerful than anything we've ever seen at Gale Crater.

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The images of the conglomerate bed are wonderful- too bad the bed got clipped by the mosaic edge. Are you sure it's steeply dipping, or is is it just an illusion due to our very oblique look angle?

John

Fair question actually, that's possible. I'm quite certain the sandstone beds below it are dipping steeply but, with only a small part of the conglomerate-sandstone contact in view, it is possible the apparent conglomerate dip is just a trick of perspective. The mission team will know the answer because they'll be generating digital elevation models as they go along.

Three cropped versions of the huge Mastcam-Z panorama of sol 406.

I'd think slumping and turbidites, also. "Jezero Creek" is depositing a lot of sediment in flash or ephemeral flows, and also doing a lot of erosion and canyon cutting once it drops it's load. This is an unstable scenario and we're going to see slumping.

--Bill

A comparison with an image from a greater distance on sol 402 shows that this is only a perspective effect, albeit a very impressive one. When I first saw the sol 406 image, my eyes were fooled too.
The conglomerate-sandstone contact is - at least in this place - nearly horizontal.
The digital terrain model indicates an inclination of the slope below the conglomerate of 30° to almost 40° to the east-southeast.

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Great pictures of a wonderful landscape. Here is the sol 407 circular panorama.

Looking ahead, it's not going to be easy to climb up onto the delta. It will be interesting to see how we do it.

Phil

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The east face of the delta looks completely impossible to climb. Planned traverse routes from the team show paths entering the area from the south face, which we haven't seen yet from the ground. It looks like it will involve six to ten relatively punctuated climbs. It certainly seems daunting unless those unseen slopes are very different from the ones we've seen so far.

We haven't seen it from the ground, but I am looking ahead in HiRISE images. It is presumably possible but it's going to be tricky.

Phil

I am starting to wonder whether could this all be due to sporadic water activity related to ongoing volcanism from nearby volcanic province of Syrtis Major rather than a warm wet Mars!?

Great analysis. I think you're right, it is horizontal, not dipping after all. Looking at the larger scale outcrop as well, this unit forms a horizontal / near-horizontal 'cap rock', which isn't really consistent with the idea of a bed dipping at ~30 degrees. I hope we get more images of this deposit (maybe from when we're higher up, climbing the delta?) so we can better see the contact - which I expect will be highly erosional - and also look for things like imbrication.

RE Julius - while you're right that there are flashy deposits which could be indicative of episodes of higher rainfall e.g. volcanic eruptions, impact events, orbital cycles etc the bulk of the delta likely wasn't formed this way. Based on the excellently preserved lateral migration surfaces on the delta top due to channel migration, Lapôtre and Ielpi 2020 estimate an age of delta formation of ~380,000 years, and that's based on what we see today which is a highly eroded delta. Isolated outcrops like Kodiak and Santa Cruz suggest there is a hell of a lot of delta & lake sediments that were once present but have since eroded away. So at a minimum, the lake persisted for many thousands of years. Furthermore, given that there is an outflow river channel a full 100m higher in elevation than the delta (Mangold et al. 2021), there is a whole era of this lake's history that the delta does not record: water levels were at one point 100 metres higher so the delta was either drowned, buried, or hadn't formed yet.

RE StargazeInWonder - the planned traverse route may show 6-10 climbs but this will be a very slow affair, it will not take 6 solds more like 6 months. This is because upon arrival at three forks, the next science campaign will begin. Like during the Seitah campaign, we'll return to a MUCH slower traverse to do as much science as possible. The base of the delta is the only opportunity in the entire mission we'll get to study possible prodelta mudstones. Those are of enormous scientific interest because not only do they have the highest potential to preserve organic biosignatures, but they also have the best chance of preserving macrofossils i.e. stromatolites. IF stromatolites were present in the Jezero lake, and IF they were preserved in accessible rocks, then we're likely to find them in the next few weeks and months (which is quite exciting IMO). Higher up, on the delta top, the rocks are fluvial in nature and are of less astrobiological potential. While the rover takes its time doing lots of field geology and core-taking, Ingenuity will have caught up and will be scouting ahead up the delta in order to aid the rover planners in finding their future route to ascend up.

Sol 408 circular panorama. Those linear troughs, some of them resembling the 'raised ridges' we saw before, are no obstacle at all to driving.

Phil

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Kodiak Hill imaged by Mars Perseverances Mastcam-Z.camera on sol 409. The approximate distance is 750m.
The last time Mastcam-Z looked at Kodiak it was over 3 km away, on sol 388.

Mars2020 Panorama Sol 409 by Tomislav Bandin, on Flickr

Kodiak Hill imaged by Navcam Left camera on sol 409, at 3:20 pm LMST.

My take on the Mastcam-Z Left mosaic of sol 409 and a cropped version centered on the strata. We see nice tilted strata.

Sol 409 circular panorama. A very cool place.

Phil

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Sol 410 : the backshell and its parachute seen again !
Maybe also with the debris field from the SkyCrane impact
It should be nice to take also in the near future some zoomed pictures on this hardware to gain more detail
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Sol 409 Mastcam-Z mosaic of Kodiak with enhanced colors and two "marsonauts" for scale, and an enlarged detail.

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Estimates for the timescale for delta formation vary from decades (Francesco Salese et al) to as you say, millenia. But the Neretva Vallis knickpoint level with the inner crater wall, which could be taken as the beginning of the delta, is the same elevation as the bottom of the outflow channel penetration of the crater wall. Assuming the formation of the outflow breach was due to overtopping, the lake level would have been over 200 metres above the current delta and once overtopped the flow of a few hundred cubic kilometres of water would have resulted in rapid erosion of the gap. While not definitive the implication is that the bulk of the delta as we see it was formed after the breach had lowered the lake level and bounded the depth.

Indeed

Sol 409 panorama :



Interactive version here, because some sky were shot this Sol :

Sol 411 Mastcam-Z mosaic with enhanced colors and two "marsonauts" for scale

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Thanks for the human figures. I often struggle with size/scale perspective
and the familiar shapes really help (a lot) to add value to the feeling
of "being there".

Perseverance on the move once again after pausing from driving for a few sols
Tiled Sol 413 NavCam at RMC site 22-0788
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What is the trough ahead of the rover, also visible on the orbital image? Polygonal terrain on the crater floor?

Panorama taken on sol 411 with Mastcam-Z Left. Three Forks is now clearly in sight.

Fabulous mosaic! I expect the layered units at the base of the slope, likely pre-dating the delta, will be the next high priority target. It looks like there's room between the foreground dunes to get to those units. So I wonder why the southward excursion now?

John

They could be going to the low platform directly to the west of the current position. The light-colored strata below it appear to be more favorably exposed than those to the north.

Preliminary correlation of strata:

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Unaltered image:

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Here is the sol 413 panorama in circular form. I added the two names from the press release where I assume they are located (Hawksbill Gap was shown on a map at LPSC, I am guessing the other location). This is the best view we have had yet of one of these troughs in the landscape.

Phil

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Ah, helpful to see that Hawksbill Gap is the place in front of us because the press release (https://www.jpl.nasa.gov/news/nasas-perseverance-rover-arrives-at-delta-for-new-science-campaign) suggests the mission team favours it and could spend months there. Unlike what we were driving past last week, I think the basal units at Hawksbill Gap actually have a good chance of being prodelta mudstones. Their expression in the landscape is subdued, which is consistent with softer mudstone, in contrast to the craggy scarp-forming delta front/delta top sandstones. They also seem to be emplaced in thin horizontal beds like you'd expect with lacustrine mudstone, and they are laterally continuous as Gladstoner showed us. Finally they have a distinct colour, especially the lowermost beds which have an unusual reddish tone that might indicate mud. This is all very promising! Excited to see them up close.

According to the press release, the Delta Front Campaign began on Monday April 18th and will last for six months. Time for a new thread?

Thank you, Phil! A few hours before I asked about it in another topic:


I don't have the instruments to unwrap the circular projection. is it possible to put the arrows onto some common map? Thank you.
--Cherurbino

This is a detail enlarged from a presentation Paul mentioned in the other thread.

Phil

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You’ve been heard Olivier…il suffisait de demander
https://twitter.com/jeff_foust/status/15168...3679727617?s=21

Is there any supposition of what we think that furrow is in front of the Rover on this circular projection?

--Bill

https://www.nasa.gov/feature/jpl/nasa-s-per...eclipse-on-mars

Some parts of the panorama taken on sol 411 with Mastcam-Z Left, focused on Three Forks and interesting outcrops on the delta front.

Sol 414 LMastcam-Z:
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It's a nice sequence. I was surprized that the sun looks considerably larger in mast-z at 110mm than in the MSL eclipse sequences at 100mm, allowing for the 10% focal length difference. It turns out Mars is at around 1.42AU from the sun now, near perihelion at 1.38AU (so at best the sun would appear only a few percent larger). The closest MSL's been when recording video of a Phobos transit is around 1.48AU on sol 713, I believe.

1) An interesting thing about the Phobos eclipse images is that Mars is nearly on the opposite side of the Sun from Earth, so the sunspots visible there give us an almost 360° view together with images taken from Earth at the same time.

2) Look at the wild shape of the shadow on Kodiak Hill. There is some interesting topography at right angles to the line of sight.

Not really. It's about 90 degrees ahead at the moment - and shrinking.

Thanks so much Climber for the info!
For sure, those images will make through international news