Since the main Victoria thread is now explicitly about Duck Bay and the surrounds here is another for far rim discussions.

Quite a bit more has been revealed after the last drives. Here's the MOC/Navcam match.

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James

Don't know if this thread is about Far rim but it's Far from the thread

Here would be a problem! The PANCAM will never see well!!! unless of any speculations of any Martian animals hiding among cave, bolders, or under sand from any far rim.

The only way that Oppy can see clearly of those far rim is to be up there!

Rodolfo

Quoted image removed

Atomoid, thread is about looking at the other side, not looking inside
BTW : good topic James

We've got a great long baseline for the far rim with sol 955's move. Here's one anaglyph, with sol 950 and 955 images:
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Edit: curiously the pancam frames from 950 and 955 show almost exactly the same 16 degree parts of the far rim, so it was easy to compile this.

Brilliant. I think I am seeing two areas where strata are vertically offset downward by a few metres. Don't know how to draw pointers on your image so words will have to do.
Area 1 is on the promontory in the middle of your anagblyph - approximately the right hand half of the tip appears to have slumped a few metres.
Area 2 is the whole tip of the promontory to the right. The anaglyph nicely reveals the small step up stretching across the promontory further back.
These areas resemble what may also have happened at Cape Verde.

Well done, Fred... I had same idea, this is based on Sol951 and 955 and the stitch show a larger portion (see features on the left, even though partially covered by rim):
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I didn't hear about this so far :
There's a big chunk that apparently felt down on its "nose" and look vertical now.
I find it's evident on fredk 3D there :
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If true that means that we have to find out WHY it has been eroded from below.
What would be interesting in going there would be to see the interior of the Capes.
Do you see what I mean...and what I see ?

Yes, and yes. It would also be nice to know how far the promontory cliffs continue vertically downward beneath the sand fill. Unfortunately I don't think we'll see down far enough to where the undermining occurred, but I'm sceptical about aeolian erosion being the only cause.

That caught my attention too. I don't know the correct geological terms or words to use, but it seems to me that as this particular outcrop is right on the edge of "Sofi Crater", this whole section of the far rim would have been greatly disturbed and damaged by the formation of Sofi..? Maybe the deformation (?) we see is a result of the Sofi impact?

fredk, dilo...thank you for those. When I saw the new pancams come down today I knew we finally had a good baseline that would finally resolve some of the 3D on the far rim. I couldn't wait until I came home to make the anaglyph, and I can't tell you how nice it was to simply download it from UMSF instead. Instant gratification... This place is good for that.

I don't know if he'll notice while glogging from Valencia, but if Doug wanted to showcase some of the work being done by enthusiasts at this forum, he couldn't find a more dramatic and timely image from this place than that long baseline view. It blew my socks off (which scared the cr*p out of my dog). I can't stop staring at these images. Climber previously was talking about his "caves" on the far rim. It may be a trick of the shadows, but there may be grottos there, at least.

I can imagine that this undercutting of layers and subsequent collapse we are seeing evidence of is real, and easily the result of ages of eolian erosion. I am still trying to fit this into my developing model of Victoria, but this seemingly falls right in line with the hypothesis in the Edgett paper.

Oh, and the other interesting thing we can now see clearly...The bays on the opposite side are really not as steep as they appeared in the flat-world views.

I havent really looked at extra wide baseline stereo (EWSP) pictures much, so am not sure how they distort human's 3D perception. I assume the bays are really steeper than they look in EWSP and the capes not really undercut??


Floyd

I'm a bit obsessed with the wall directly to the left of that feature and partly covered by your circle. It might be trumped by what we see in Capes B and C, but since we haven't seen those yet, I'll be over here obsessing over that little wall.

There's a ghost crater over there...

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Can that help tell us about the depth of the dust covering the slopes?

A lot clearer on one of today's pics...

Stu: I'm not sure, but I think all we can say is that the dust must be deeper than the bottom of that little crater. But that does tell us something.

Well, you might want to have a look. The perspective in the flat images suffers from the perceptual "distortion" of slopes being foreshortened. I find the extra distance information from the long baseline stereopairs to be very helpful for getting a clearer picture of the structure of this crater. Think of it not as a distortion, but as a better resolution of distance. Without them I never would have noticed that some of the opposite capes have more significantly overhanging ledges than any of the nearer capes we've observed. Maybe it's just me, but I thought fredk's and dilo's anaglyphs were some of the most exciting views we've seen so far. I think they give us the first clear glimpse into some of the steps in the evolution of this crater's exhumation.

Then again, maybe I'm nuts. It looks like a geomorphologist's dream over there, to me. I am still staring at some of those opposite buttresses and imagining a long story of undercutting, collapse, and removal. Let's get the big panorama done, the conjunction behind us, and then let's start exploring the rim of this crater. I'm sure we'll surprised again and again before we enter it.

You're right, Stu... and there is another not far from it, as shown in this crude, dirty stitch from Sol957 PanCam imagery:
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Both are clearly visible in MGS image.

Stu,

I'm really surprised that your ghost crater could have survived for long on the talus slopes of one of the VC gullies. I would have expected erosion of the VC walls to have buried this long ago. So is it a recent phenomenon?

Aberdeenastro

(previously known as Castor - that's a story for community chit chat later...)

Do these "ghost" craters provide the opportunity to look at the deepest rocks? Below certain level, there is no exposed rock, except in the "rimlets" of these craterlets, so I think that these small craters will show the deepest (and hence the oldest) rock layers.

The ghost craters we see in these Navcams are likely impact features _on_ the talus and not on the original surface of the crater bowl. I don't know what the range of depth:diameter ratios are for impacts in unconsolidated material, but a crater could give us an idea of the talus depth here. And does give an indication of the stability and mechanical properties of the talus material.

Got any materials engineers aboard?

--Bill

With the move onto Verde we can see new parts of the southwest rim. Here's a long baseline anaglyph made from navcam imagery from sols 957 and 958, which gave a good baseline in that direction. The 958 imagery is from Indian3000's fabulous pan.
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This cross-eyed crop shows the interesting apparent "collapsed rim" region, capes O1 and O2:
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This shows the same region from above with O1 and O2 circled:
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Which reminds me, time for another far rim vs MOC image comparison.

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I've used yestersols (958) navcams as tosols arn't complete yet -the only real difference is that tosol Cape D1 can be seen beyond the beacon.

With a bit of luck come tomorrow we may have a better orbital image.

James

Which we do.

Here's what Oppy sees from the side compared with what HiRise sees from above.

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James

EDIT: Note that the HiRise is reduced down to approximately match the navcam resolution - I can't wait for the pancams!

That's awesome, James. The new MRO view has been freaking me out all day, but that comparison is mind-blowing. In some ways, it appears that the HiRise camera can see the opposite rim almost as clearly as Opportunity can. In fact, because Opportunity is viewing them at a shallow angle, it can barely see the small dark ripples on the slope below the cliffs on the left, but they are quite obvious to the orbiter.

Some have suggested that such high resolution imagery from the orbiter might take some of the mystery from this adventure. My personal opinion is that it will only add a whole new and deeper dimension to the mystery. This has been a very good day for anyone who enjoys planetary exploration. Congratulations to the many teams of scientists, engineers, and yes, even the administrators, who have made this Martian synergy possible. (Oh, and all of you fine tax payers, too; even though most of them didn't even notice this grand achievement.)

Now that is a comparison. Seriously, what gift this new orbital image is.

I agree with you, mhoward

- "an image fallen from the sky "

I wanted to compare our previously best MOC image to the new MRO image. This animated gif is so much nicer with a few transition frames, but I couldn't get it below the limit without further reducing the image quality, so I had to reduce it to two frames. It may not be a truly correct comparison since the best version of the MOC image available to me was the recently released subframe jpeg, which is surely not as good as it could be compared to the quality of the MRO image released today.

Anyway, we have been looking at the MOC image for quite some time now, and we've commented on how much better it was than the previous MOC that was not captured with c-Proto technology. But this new step change in image quality is seriously impressive. I have tried to do minimal damage to the original images while constraining this file to less than 1 MB in size. I am sure that both images are degraded in some ways. I had to rescale them to match and also to rotate one to match the other.

The viewing geometry of the orbiters is different, and I have no idea how to adjust for the perspective differences, so I simply tried to register the images as best I could on the dune field at the bottom of the crater, so the crater rim jumps between the two frames. My original intention was to look for changes in the dune field geometry. I also tried to find some boulders that might have recently fallen from the cliffs, but I do not see any convincing changes in either. If you have animation software, take these 2 frames and insert some fade transitions.

Wow, this is better than taking a new car for a spin...
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Great work, Tom. Interestingly, there are some ways in which the MOC image gives more information than the HiRISE image; the MOC image shows albedo differences more dramatically than the HiRISE image. I'm sure this is because of the higher sun angle. High sun angles give you better albedo differentiation and tend to wash out fine detail.

I'm sure that if HiRISE imaged the site at the same sun angle as MOC did, you'd see more similarity in the albedo features of the two images. But as it stands, it's actually helpful to have the MOC image to show you where to look for rocky strata exposed at or near the surface, since such features are somewhat less obvious on the HiRISE image.

Finally, after staring at your gif for several minutes, I keep thinking I see a boulder in the HiRISE image that doesn't have any correlated bright or dark spot in the same position in the MOC image. It's off one of the capes to the north-northwest, perhaps closer to straight north. (I don't have the gif loaded at the moment, and I can't get back to it while typing... grrr... so I can only rely on my less-than-perfect memory, here.) I can see correlating spots for a boulder slightly north of the one I'm talking about, and a conspicuous lack of anything at all visible below and south of it in the MOC image.

I don't see any changes in the central dune field, however...

-the other Doug

If you could point that boulder out, I am sure many would appreciate it. One would think there is a decent chance that something different could be observed between the two images.

Actually, I'm sort of impressed by this little coincidence -- the boulder of which I speak is the boulder that appears to lie at the end of a boulder track on the inside slope of the crater, as seen in a detailed subframe in this post by Antipode in the "...from overhead" thread.

As to the exact location of the cape -- drat, I don't have any of the naming conventions in front of me for the capes and bays. Well, let's see -- the next cape to clockwise around the crater is the Beacon, right? The Beacon cape, as seen from overhead, has a very sharp cut in it and a second smaller peak to clockwise of the most uplifted cape. But since this whole affair lies between two shallow bays, I count it as one main cape.

The boulder I'm talking about has rolled down from the counter-clockwise side of the next cape to clockwise from this Beacon cape complex. I'm pretty certain that the subframe in the post I linked above shows the same boulder.

-the other Doug

I just brought up the full-res png image, and I'm positive, the boulder with the boulder track in the inner slope is the same boulder I don't see in the MOC image.

I also, after a quick but careful look around the full-res image, don't see any other boulders on Victoria's inner slope with boulder tracks. I don't see anything else that I convince myself is a boulder track at all. (And I can imagine that such tracks would get smoothed off by winds and slope pretty quickly.)

I'm thinking this boulder came down the hill since the MOC image was taken.

-the other Doug

CR/o'Doug, is this boulder and track you are discussing? It is the same as the one in Antipode's post in the other thread; I have cut it out, de-jpeg_artifact'd it and enlarged it ( I _do_ need to get the non-jpeg full-res image!) so it is clearer. It does show a bouncing and rolling movement quite clearly and stands the best chance of being quite recent.

--Bill


PS-- I've added (even though it shows as the FIRST image below) a grayscale from the earlier MOC image of Victoria. This is a slightly smaller scale and shows a slightly larger area, see if you can spot the "errant" boulder. Report back with x:y pixel coordinates; my finding is 1700:2950. Try making the color MRO image grayscale and doing a gaussian blur to make it similar to the earlier MOC image.

I think this is another rolling boulder smaller and not so bouncy and on the far side.

Roy F
Edit a context picture added for clarity

You had to reduce the quality of an orbiter image to get it match a rover image! Did anybody say that the HiRISE images are amazing!?

Anyway, the full panorama must be breathtaking.

Darn it, Bill, I don't have Photoshop right at the moment,, so I don't have the ability to give you x:y coordinates. However, I can identify every other rock from the HiRISE image in the MOC image, but not the "rolling" boulder. In your grayscale image, the boulder ought to appear just above the bottom of the image, below a triangle-shaped grouping of boulders, and I see nothing in that position.

-the other Doug

On the new image, there's a linear feature in the sand near headland H1. Oppy's images ought to include it, but I've not been able to spot it on them - any thoughts on whether it appears in those images/what it might be? An Anatolia-style feature? And yet it's in a crater... Or just a straighter dune?

- edited for clarity

Unfortunately these boulders are near the limit of the resolution of MOC. But I think the boulder in question, at the end of the bounce trail, is visible in the MOC image. I've lined the two up and made a flicker gif:
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OK, Fred -- with that flicker-gif, I have to agree, there may be an almost imperceptible brightening in the MOC image where the "rolling boulder" appears in the HiRISE image. And, to bolster that case, another boulder upslope of the "roller" looks rather similar in the MOC image, a very faint brightening.

And while a closer inspection of the HiRISE full-res image of Victoria does show some other features that might well be boulder tracks, none of them seem anywhere near as fresh as the one we've been discussing.

Ah, well...

-the other Doug

I think that the linear feature is an "anatolia feature" which was first noticed near Eagle crater. These features are apparently solution-widened fractures that actively sap (drain) sand from the surface, leaving the linear troughs in the sand. Or so some think. There is another lineation on the ejecta apron just south of this bay; a clip from the PIA 08813 image is appended.

--Bill

Agreed, Bill. The linear features on the inner wall in your posted subframe really can't be boulder tracks, in any event, unless Martian boulders roll sideways to the slope and not down it...

-the other Doug

Hi Guys looks like I misjudged my 'boulder track' the downhill slope should have rung bells never mind.

Unless someone pushed it.
Roy F

That's quite convincing fred, good job!

Good flicker-GIF, fred. Here is my interpretive image: the MOC and MRO subframes with lines drawn between features. Blue is "other", yellow is "mystery" boulder. It is good that we are able to compare the two images; this boulder is a good test because it is about at the limit. I'm sure we'll spot changes; if not now, then ten years from now.

I'm glad to see a supposed "anatolia trench" in Victoria. Perhaps we can also see one in the rim wall.

--Bill

Thanks fredk. I planned to do one of those, but was sidetracked. Yeah, we really are pushing the MOC to its limit with these comparisons. I went back to the pair of orbiter images, re-aligning them in all of the areas where boulder tracks had been identified, and it seems that the boulders are always visible in their terminal positions in both orbiter images. Even if we don't identify some very recent changes in the crater (that was a long-shot anyway), it is very cool to see the bouncing boulder tracks. Congratulations to Antipode for being the first to spot one. I totally missed them on my first spin around the crater.

It is interesting that the boulder tracks we can see are all on the northern side. There might be a number of explanations for that, but it might be related to the fact that most of the tallest cliffs and steepest interior slopes occur on the northern side.

I saw that linear feature to the SE, but for some reason I didn't think of it as possibly anatolia-like. That is an interesting thought. Not too far away, on the eastern side is that other linear feature near the wall that was mentioned in the press conference as a possible dike. Hmm... While a dike would be quite interesting, it would be the first occurrence I am aware of in Meridiani of volcanic activity. It would seem more logical to assume it was some kind of fracture fill.

Exploring this crater is going to be so amazing. Every time I open the full res version of the HiRise image, it almost brings me to tears. While it is going to be painful for us all to wait through this conjunction, I think there is more than enough detail in this new bird's-eye view to keep us productively occupied for a few weeks. Life is good.

Exploring this crater is going to be more than amazing, it is going to be fun. Not only do we have a high resolution camera in orbit, we also have two mobile/semi-mobile ground truth stations on site.

Dike? Humph. Do you know where on the eastern site is is located?

--Bill

Bill
I think this is the Dike they referred to in the briefing
The spelling I would normally use Dyke got me a 'may couse offence' message from Encarter dictionary


Plenty to see and do
Roy

Right. That is the feature that was visible when they mentioned the possible dike.

I'm doubtful that it is a dike. We haven't seen that many volcanic features in the locale. It looks more to me to be a slump involved with a fracture. We'll see soon enough; this may be an chance to see a cross-section of an anatolia feature....

--Bill

I'm doubtful too. However, it is surprising that they (actually, I think it was McEwen who made the comment) would speculate so unless there was some other evidence. I wonder if they might have some additional spectral information from one of the other MRO instruments. Then again, perhaps it was simply early speculation made in the excitement of the moment. One thing that has been apparent about Victoria for a long time is its roughly hexagonal shape, which at least suggests that a fracture system of some kind may have had an influence on its shape.

I am still freaking out over the HiRise imagery. It is fine beyond my wildest dreams. I think I am hoping for a full circumnavigation, perhaps with several entries and exits when safe slopes are identified. I suspect that what will actually happen is that some lesser amount of circumnavigation will occur, and then an entry. If they later manage to exit successfully, they will look for another interesting entrance and repeat.

Conjunction? What conjunction? I will happily get lost in the orbiter's image for a few weeks and hopefully I will not miss my regular MER fix. I guess it will be kind of like a junkie going on methadone maintenance for a spell, while his dealer is in the slammer.

The latest pancams (sol 986) give us a great long baseline with the Duck Bay pan. To me the area around Sofi Crater and Climber's "caves" is visually most interesting:
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Viewing the side-by-side version with Stereophoto Maker is the best!

In 3d the "caves" certainly look like they're probably at least shallow cavities in the cliffs.

Long baseline, colour anaglyph of the far rim.

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I just love looking at the Soup Dragon in this image.

James