Looks quite Fram-ish

Doug

Thats one of the missing pancans from yestersol. I wonder if Opportunity drove today. I guess we'll know in about an hour.

um.........I don't see Viking in that picture.

See those rocks - thats a crater

Doug

OK, I see it now. It's barely visible in the upper right. I thought you were talking about the rocks. I had to lighten the image on my screen to see it.

With Autostitch (accidentally the horizon become flat by playing with the menu items ):

http://www.greuti.ch/oppy/oppy-sol414.jpg (filter L2)

That should be one of the crater from the satellite image?!? Is it the same as by vostok?

Actually - it's both of them, looking like they're next to each other because of the foreshortening of the camera



Doug

It's also a such sea condition here, one can look behind this waves not at all

Yes, it does, doesn't it?

"Fram-ish" could be better characterized, I think, as "a relatively young, fresh impact crater with blocky inner walls and local blocky ejecta arrayed roughly one crater diameter out from the rim."

I'm fascinated by the erosion patterns being defined by these crater morphologies. Obviously, Viking is an Eagle-sized crater and both seem to have been caused by very similar impacts. Viking, like Fram, has a more extensive exterior ejecta blanket and blocker inner walls -- it seems to be younger and fresher.

The lack of inner blocky walls in older craters is a no-brainer -- mass wasting and slow aeolian deposition means that rubble slides to the bottom and is then covered by wind-blown sediments. But the virtual erasure of the ejecta fields around Eagle-like craters shows just how easily eroded the excavated rock must be. Especially compared to the blueberries that resist erosion. Or even compared to basaltic rocks, like the ones we see at other landing sites -- at Gusev, for instance, the rocks haven't been eroded down to a smooth plain by billions of years of aeolian erosion, like they have at Meridiani.

I think there is a paper to be done, somewhere, on the erosion patterns of the concretion-rich evaporite rocks at Meridiani Planum. You'd almost think that, if aeolian erosion is the only factor in the reduction of the evaporites and subsequent paving of concretion materials, that you would only erode the evaporite down a centimeter or two, until it developed a thin layer of uneroded concretions that would protect it from the winds. Obviously, there has been significantly greater erosion than this, or else Oppy's tracks would be uncovering evaporite subsurface everywhere it went... so the evaporite must have continued to erode after it developed a thin layer of concretion materials.

I'm sure that aeolian dust deposition has something to do with the current state and depth of the regolith, as well -- but if we postulate that the depth of the regolith is primarily due to windborn dust deposition, you have to explain what "gardening" processes result in so many concretions sitting at the surface. And in any event, adding more covering material in the form of windborn dust deposition just reduces the evaporites' exposure to wind erosion even further, and there has to have been a *lot* of evaporite erosion to account for all those loose concretions.

I also have to wonder -- the composition of Meridiani soils and the evaporites are somewhat different, right? The soils seem to be basalt dust/sand (windblown deposition) mixed with concretion elements and *not* an unusually high concentration of the salts and sulphates that make up the evaporites.

So, when the evaporites eroded and left all these concretions littering the landscape -- where did the material go? Is it so thoroughly mixed with the global dust that it's one of the major constituents in the global dust's sulphate and salt content? Or are there large "traps" of eroded evaporite dust lingering somewhere nearby?

Just curious...

-the other Doug

Hi Doug,

Your discussion hits close to a question I've had ever since Oppy left Eagle crater and we saw the whole plain covered with the concretions/Blueberries (BB). It almost seemed in many places like a complete, uniform covering of BBs. My question basically is this: What depth of evaporite would have had to be eroded in order to get that density of surface BBs? There must be some idea as to the BBs occurence density within the evaporate (We've ground into it, microscopically examined it, etc). Think of it this way... if the evaporate were transparent (say, like Jello with, well, blueberries suspended in it) and you could "see" the BBs within... how thick would the layer have to be so that any line of sight into the layer intersects a BB? (almost like Olber's paradox). Thinking back to some of the photos of BB's just on the verge of emerging out of the evaporate... it seems like it would be less than 1 BB per cubic centimeter (BB/cc?). In any event, I would think it would take more than an inch or two of erosion to get the surface BB count seen. ... perhaps several feet... even meters?

That then gets to your issue: where did all that powder go? ... blown away? One would think some salt concentration should be there in the soil. Perhaps once you finally obtain a uniform, protective layer... erosion of the evaporate halts or slows significantly. Once you know the thickness removed to get the observed BB cover, then you can start asking other questions like... how long would that take, etc.

Well, just wanted to pass along a few thoughts.

John/RedSky

Nicely visible there

Doug

Hate to sound negative, but my first impression is "underwhelmed".

I expected more of a surface expression.

But, I see some interesting features. Layered, angular, dark rocks in the foreground. Ledges of the light evaporite on the crater rim.

Take a breather, get out the handlens...

--Bill

That can't be Viking, can it? Viking is deeper and has a mostly intact rim. It doesn't seem large enough, either. Surely, it is one of the smaller, harder to resolve craters to the north.

I'm lost.

OK, My bet is that we're not at Viking. There is a small crater at 11:30 from Viking. I'm betting that's th crater we're at right now.

The latest directors update says were about 80m from Viking. Viking and Voyager would appear just like that at that range. Both appear to be falry fram-like from orbit.

If you take into account that they are the right objects at the right range, and the director updates tell us where we are, then yes - those ARE viking and voyager.

Doug

hummmm.. I guess I was expecting something different. (shrug)

scott

Viking doesn't look like much because the near rim is higher than the far rim. All thats visible now is the debris laying outside the rim. Wait till we can see inside.

I'm still betting that post #14 is not Viking or Voyager.

They've deployed to IDD on the crest of the dune.......but arghhhhh no navcam/pancam images of the crater just in front lol

pancam of part of crater just in front of them, L5and L6 also available
http://qt.exploratorium.edu/mars/opportuni...00P2663L4M1.JPG
looking west so this one is the tiny crater west of position marked

Wonderful. And we're just getting into the region with the prominent dunes.

--Bill

Where the heck are we?

"looking west so this one is the tiny crater west of position marked." (Alan)

Alan:

That was my best guess as to a correlation with the orbiter image. But I was working from this pancam from Doug's post #11:
http://207.7.139.5/mars/opportunity/pancam...00P2395L2M1.JPG

I'm not completely certain of what I think I am seeing, but what I am interpreting as the near and far rims of the crater in my linked image, seem to be interpreted by others as two different craters.

Wherever we are, it can't be Viking.

Alan nailed it with this image

http://img236.exs.cx/my.php?loc=img236&ima...toerebus5vp.jpg

Thats where we are. That L4 image is looking west past a small crater - the other images are looking south toward viking and voyager

Doug

Here is a 360 stitching of the R2 images taken by Opportunity at site 52. It's a bit of a messy stitch, please excuse the "smiling" horizon...but it is sufficient to put the images in context I think.
I'm not convinced yet that we're looking at Viking/Voyager except on the very distant horizon. The larger feature to the south doesn't even appear to have a fully intact rim, it just looks like a nearby jumbled outcrop and another one a bit further away. What I'm refering could also be the visible part of both V&V. It isn't a great perspective on the scene(the L1 and R2 360 pano was taken at half res), when they travel a bit further south to the 'rim' of the the rest of the crater may well pop into view as suddenly as Eagle disappeared when they drove away...time will tell.

In the very middle of your mosaic is the small crater just to the West of our current location - and then 4 to 5 frames to the left of it is - going from right to left - Voyager, then Viking.

I'm amazed to see so many people saying "I still dont think we see them" or "It cant be viking".

It is. That is whee we are. They're right there in front of us. Alan has us nailed with that most recent location image.

Doug

Thanks, Slinted for your excellent stitch. For me it was quite the opposite and confirmed almost the exact location when compared to MSSS overhead view. Take a look at the attached image which I marked up with the nearest features visible...

THanks P - that's what I was going to do when I got in to work

Doug

So now you can really get some work done

Great 360 degrees view. Thanks for stitching Slinted. Have you it done with Autostich (frame to frame - wouhhh)?

BTW, I agree with Doug and Pando - where should we be otherwise? Also the shape of Endurance silhouette is coherent.

Pando have you this MSSS section blow up from the original? Are the dunes really visible - that's amazing! Which MSSS original image is it? Could one compare the size of the dunes between the location of Endurance and by now?

Yes, this is 1.5m/pixel image blown up 200% from the original (which makes it 0.75m/pixel). I think the dunes are starting to get visible right around here and on further south. That's why I said back in the route map thread that there are some monster dunes visible around Albert... er.. Erebus... with 30m or so crest-to-crest!

Here's the source - note that I used the "Full sized and map-projected image lossless GIF" file which you can find as a link on this page. Internet Explorer can't view GIFs that large (21MB!) so you have to right-click on the link, save it, and then open it up with your favorite graphics app:

http://www.msss.com/moc_gallery/r10_r15/im...5/R1502302.html

And here's a 3d bird's eye view of the current location:

Thanks pando, looking at that view, I'm convinced. The other MOC cPROTO image also has some great detail to help us figure this out, and your labels looks spot on with the features in the image.

Autopano and ptassembler did all the work in that one. The R2s had less data dropouts than the L1s, the L1's will probably make a better image when they get them down again. But the source images were highly compressed, so there's only so much detail one can pull out. And still no navcams from site 52... I'm looking forward to some better views on this scene.

http://qt.exploratorium.edu/mars/opportuni...B5P0627R0M1.JPG

http://qt.exploratorium.edu/mars/opportuni...B5P0627R0M1.JPG

WOW !!!!!!!!

The funny (or sad) thing is, the official mars rover site still says: "Opportunity: Arrives at 'Vostok' ".

Viking's rim looks too dangerous to approach, so I hope they'll take some pictures and move on.

Now this looks better. This "is" what i was expecting. Sooo many rocks so little rat.

What are the chances they hang around here for a bit?

scott

Well, Doug, I can only speak for myself. But based on the image in post #11 in this topic and your comment "Nicely visible there," and comments from others, I assumed that you and others were calling what is now unofficially named The Outcrop, Viking and Voyager. They are barely discernable in that L2 image (below), so I didn't even see them at the time.

It's funny how clear it all is, now that we have a few new, key images. I wish I would have had slinty's nice panorama last week.

So, what do you estimate as the distance to Viking, about 100 meters?

"Sols 421 and 422 (March 31 and April 1, 2005):
Actually, this is kind of neat. As this report is being written, Opportunity is on Mars driving away from this soil survey spot and heading toward the "Viking" crater. When it gets there, it will stop and image the crater for two days."
http://marsrovers.jpl.nasa.gov/mission/status.html

Opportunity's update is actually up to date.

Apparently so. This navcam looking back at the tracks suggests to me that the dunes are now higher than they have been in the past. I don't recall seeing so much of the tracks disappearing behind the dunes in past images.

http://qt.exploratorium.edu/mars/opportuni...B5P0627L0M1.JPG

Great view of Viking!

http://qt.exploratorium.edu:16080/mars/opp...B5P0627L0M1.JPG

Sorry haven't seen Sunspot posted this already

Wow, quite a lot of rock exposed here - almost like the meteor exploded right after hitting. Sheesh. I wonder if they might do a little work with the IDD, or stick to their 2-day observation schedule? It would still be nice to see Victoria Crater.

I think we've been so spoiled by intact layers at Eagle and Endurance that it's hard to get excited about a pile of jumbled rocks. I'll bet it's not long before the search for more intact layers -- in the etched terrain or Victoria -- resumes.

Instant panorama of viking

The L2 and L5 images that are in this sequence are about as highly compressed as I've seen anything since the start of the mission, probably to save bandwidth/storage space. In order to take advantage of the L7's not being so compressed, I tried this pano with the L7's as the luminance channel, and color from the 3 filters. It's a bit of a mess, balance between frames is way off and color is very much false(enhanced? heh). But it does give a good bit of detail on the crater features.

I'm going to try this one again later, with as much pre-balancing as I can. But I figured I'd share this 'work in progress'.


Opportunity Sol 422, Pancam

Any guesses as to the relative age of this crater (even relative to Eagle)? It looks "fresh" and well-defined from the MGS image, but there's a lot of sand inside the crater. Does that build up over thousands, or millions, of years?

Do we assume that the vast majority of the impact craters are very ancient? Obviously Vostok was a real old one. However, with Mars' proximity to the asteroid belt and thinner atmosphere relative to Earth, I would expect that there would be a lot more meteors the size of a car or house striking Mars every year and making craters this size.

Did we ever get a guesstimate on the age of the meteor near the heatshield? Had that one been sitting there for hundreds, or thousands, or millions of years?

Oppy has been putting its head down:

last one is vostok

First off, a meteor the size of a car would blast a crater a mile or more wide. A meteor the size of a house would blast a crater something like five to ten miles wide. Viking was made by a meteor more the size of your fist (by the time it impacted, anyway).

Secondly, the rovers don't carry the kind of equipment needed to come up with wild-ass guesses as far as absolute ages of rocks are concerned. There is no way at all of even guessing how old that meteorite was, or how old any of the rocks that have been analyzed are. (There is a good thread in the MSL category on the kinds of equipment needed to date rocks even close to accurately.)

Finally, I don't know that anyone has ever calculated the difference in the number of Mars-orbit-crossing objects and the number of Earth-orbit-crossing objects, but I'd be willing to bet that the difference is fairly minor. Over billions of years, the population of objects thrown towards the inner system from the asteroid belt has probably evened out and is relatively constant from the inner edge of the belt all the way in to the Sun.

You do make a decent point that Mars has a thinner atmosphere than Earth's, and therefore more smaller objects reach the ground there than here. But remember that a vast majority of the meteorites seen on Earth are the size of a grain of sand (or smaller), most of which are the remnants of broken-up comets -- which will burn up in Mars' atmosphere just as easily as they do in ours. And while there more fist-sized objects that reach Mars' surface than ours, I'm sure, I doubt the rate of impact is any higher than we see, say, on the Moon. And the seismometers we left on the Moon showed that such impacts are pretty rare -- only a very few were seen in the years the ALSEPs were operated. And only a single impact of a car-sized object was recorded on the Moon in those years. (Not counting man-made objects, of course.)

We really don't have good enough empirical data to characterize the meteor flux at Mars. I'd be willing to bet, though, that any crater at Meridiani where the rocks of the exposed evaporite layer are semi-rounded and have shed a bunch of concretions (as Viking appears in the images) wasn't made in the last few hundred years. A few hundred thousand to a few million, I'd buy...

-the other Doug

I know that the rovers didn't have instruments to gauge the age of the meteorite... I was wondering more from the secondary evidence, e.g., that the object was still relatively shiny (not terribly oxidized or dust covered), that it wasn't half-buried in sand, etc. I guess the situation is somewhat similar for the meteorites found sitting on the ice in Antarctica, unless they were uncovered by the ice being eroded or melted out from around them.

Yeah -- we can make some pretty decent estimates of stratigraphic sequence, and we can try to gauge erosion to make a wild-ass guess on the amount of time a given object has been in its current position, sure. But any guess of this type would really be WAG-ish, with vast error margins.

Honestly, Viking looks a lot younger to me than Eagle, but significantly older than Fram and what Doug has named Mini-Fram. There is almost no sign left of Eagle's ejecta blanket, while Fram and Mini-Fram sport obvious debris aprons that seem to sit right atop the plains material (and even atop some duneforms). Viking's ejecta blanket seems to be sort of midway between the two -- there is a lot of jumbled evaporite lying out on the surface outside of the crater, but much of it has been filleted, partially buried and even eroded down significantly closer to flat than we see around Fram and Mini-Fram. And while Viking's floor is duned and completely filled with dark concretion materials (plus windblown basaltic dust), you can still see some relief created by the jumbled-rock floor that lies beneath the dust/concretion fill. Eagle's floor had completely smoothed out, with no sign remaining of the jumbled relief that must lie below its current floor.

I think one of the factors here is that Eagle is slightly larger than Viking, and probably sees a slightly different wind pattern (as is evidenced by the differences in duning between the plains around Eagle and those around Viking). But I also think that Eagle is significantly older than Viking, and the additional aging and erosion have smoothed out its features far more than has occurred at Viking.

Of course, there is always another possibility, one that has occurred to me more than once -- it may be that Viking, like Fram and Mini-Fram, is a true impact crater, while Eagle is a sinkhole (i.e., not formed by an impact event). That would explain the differences in the crater morphologies, as well. However, I think that it's more likely Eagle and Viking are both impact craters, and Eagle is just older.

-the other Doug

I hope this isn't too far off topic, but has a crater been identified that might have been formed by the heat-shield meteorite?

Yes they did although it wasn't a real crater. Infact they drove up right to the heatshield crash site itself:

http://paranoid.dechengst.nl/mars/heatshield.jpg

http://paranoid.dechengst.nl/mars/heatshield%20color.jpg

http://paranoid.dechengst.nl/mars/heatshield%20color2.jpg