Oppy sol 1311 colorized MI panorama:



with links to location and original panorama -- which has links to 3D pairs.

An experimental MI dust correction was applied to the images before autostitching the panorama.

Brinesplat vugs, happens all the time in Barsoom...

Hello,

In late for many images, but that's all that I can do now.



I have trying to eliminate dust darkening with a flat picture I've build from a sky left pancam observation. I give you the flat-dust-corrector (not very perfect on all the images, optimised for L2 pics). I'm working on obtain better results (this flat do not correct over-exposure on the left pictures due to a dark part of the image). Work with a simple addition mode.

Nice tool, Ant!
I tried it and works, however the sum gives a reduced contrast on the right portion (as foreseable). See below for example:
Click to view attachment
Perhaps, a multiplication flat field would behave better (I'm not sure, however)... what do you think?

I read Skyelabs link and it seemed to be saying that vugs in carbonates were often formed by solution by water. This made me think that the vugs in the white band of Victoria crater might be caused by solution by near surface ground water shortly before Victoria formed.

Perhaps there is now evidence of water at merridiani both at say 3.5 billion years ago when the evaporites formed and at say 2 billion years ago when Victoria formed. Perhaps this is part of the same story as the dessication cracks seen at the bottom of Endurance crater.

PS I appologise for multiple posts. It is difficult to post using my mobile phone.

You need to do a bit of both (and the amount is dependent on the amount of stretching).

James

to flatfield compensate an image you just divide the data with a normalized flatfield image. multiplication or addition is just not right in my book...

/mattias

OR you can multiply with the inverse of the normalized flatfield.
The reason it's not as simple as that with jpegged raws is they are histogram stretched and so is the flatfield effect. You'd have to something like stretch the flatfield the same way before dividing to remove the effects, anything else is bound to leave residual noise.

I've entertained an idea that if you had the proper flatfield (by proper I mean it really minimizes high frequency noise and other large scale nonlinearities, but principally noise) and if you had a linearly stretched raw image, in theory you should be able to work out the rough inverse of the histogram stretch by dividing with the flatfield while modifiying lowest and highest DN values until the output residual high frequency noise is minimized. It would then give you the rough initial min. and max. brightness levels before the stretch. Of course, one has to consider what metric (Fourier filtering?) do you use for determining when the residual flatfield noise is the smallest (as opposed to actual high spatial frequency real details). There's also the fact MER images are mostly LUT encoded IIRC, add in JPEG artifacts and this doesn't realistically pan out. Still, it's a thought. Might be only worth it for sky shots which are pretty bland anyway...

Why aren't the image planners just using more overlap and then just cutting away the bad parts? Will take more images to get the same pan, but it will look good

Agreed, more or less. Ignoring crystallography, the vugs might represent frost-leached or heavily-hydrated former chloride crystals, such as antarcticite or hydrohalite (both unstable much above the freezing temperature of water), or they might instead represent so-called meridianiite:
http://www.lpi.usra.edu/meetings/7thmars2007/pdf/3124.pdf
a heavily hydrated magnesium sulfate that is likewise unstable much above freezing, or they might even represent tiny ice crystals that later sublimed. Very difficult to say at this point without more data. Their extremely fine grain size and finely dispersed nature suggests to me that they probably are not normal evaporite crystals, formed by direct crystallization from either liquid surface water or liquid ground water, and likewise that they were never soaked in such warm liquids. They could have formed diagenetically, or immediately after deposition of the originally damp rocks in which they are found. As always, feel free to disagree.

BTW, if you look up the MgSO4-H2O phase diagram in that meridianite reference, you should note that the freezing point depression of magnesium sulfate, the most soluble common sulfate, is only about -4 degrees C, in contrast to common chlorides that (in combination with ice) can still form liquid brines at temperatures up to nearly 50 degrees colder. That is why we feel that very cold subsurface brines on Mars, if any, should be strongly enriched in chlorides instead of sulfates (contrary to what is commonly inferred from the sulfate-rich surface mineralogy). The sulfates might be trapped at or near the surface of Mars simply because they cannot easily be frost leached, except at comparatively high temperatures. Again, feel free to disagree.

-- HDP Don

Meridianiite! Thanks for pointing that out. After a little Googling I see that the earthly occurance of the mineral seems to have been discovered by the same Canadian guy who created the stuff from epsom salt solutions in his garage in the winter, and then went out to find it in the field. I recall reading about the garage experiment last year, but hadn't heard about the field discovery. It's a very cool story. I am no mineralogist. Is there any reason to suspect its crystals would fit into the observed vugs?

As for the "vugs," I'll agree that some of the things we are seeing in the recent MIs resemble vugs we saw back at El Capitan in Eagle Crater and other rocks right up to Endurance. But these seem noticeably smaller and less well defined than some of those observed early in the mission.

Another thing I can't help but notice is that I really can't identify any original grain outlines in the new MIs. I understand that we are looking down onto the bedding rather than at a cross section of it, but I can't help but wonder if this rock has been significantly altered. I don't know how much the MIs have been degraded by recent dust accumulations on the lens, so that makes interpreting the raws difficult. I'd like to see some MIs of a vertical cross section next.

Oppy sol 1294 L257 2x3 panorama:



Lots of synthesized missing data. I applied a variation of the Ant103 dust mask as a division by the inverted mask plus an offset.

I am ready to give up developing a simple "ACME dust correction" (beep, beep.)

Please, please JPL, apply the dust correction before creating the "raw" JPG images!

I'm going to wait for the missing data for that one i think.

Here is the view on the other side on the same sol. L7 only at this stage, I'll drop in the colour when it arrives.

Click to view attachment

James

I too mad(e) a stitch of upper frames only, using Ant103 "flat field" and lot of work attempting to adjust contrast differences (not completely succesfull!):
Click to view attachment
NB: artificial sky

sounds pretty cool but even in really great conditions you would probably have an errormargin that is way bigger than just guessing...

another approach would be to use information from the earlier released raw images.

One could probably use the time of day (sun elevation) to estimate the DNs expected for known albedo targets in an image. the dusty sand seems to be pretty much the same color in every picture so far. so you only have to find one patch in shadow and one in direct sun and you would be pretty much golden...

/M

The first pano I've made with the flatfiel I've created. Needs some adjustments during the processing. Frame per frame, different opacity level if it's a L2 picture or a L7. But it seems to work in the final result .
Non definitive pic. It miss a lot of data as you seeing it.
I remarked that stitching is harder with this dust deposition

Agreed, it's a cool story. However, I'm not sure if it's true. The observed vugs are extremely elongated. Many, many minerals can grow with elongated habits; meridianiite (low temperature hydrated Mg-sulfate) might well be one of them, I don't know. I can, however see a different problem with the elongated vugs representing former Mg-sulfate crystals. The rock matrix, at least where the vugs were first seen, is allegedly rich in Mg-sulfate too (up to 30%). Logically, I can't see why Mg-sulfate crystals would preferentially leach out of a rock that itself is rich in Mg-sulfate - sort of like asking certain calcite crystals to leach preferentially from limestone or marble, or certain salt (halite) crystals to leach from a bed of rock salt. Where you see crystal-shaped cavities (molds), the mineral involved was typically much more soluble than its matrix (e.g., elongated gypsum-shaped molds in sandstone), or chemically unstable with regard to its matrix (e.g., cube-shaped molds in vein quartz that indicate the former presence of the iron sulfite pyrite, since weathered away). While it's possible that there were elongated crystals of meridianiite, the more hydrated form of Mg-sulfate, in a matrix of the less hydrated form, and that they became unstable on heating to just above their breakdown temperature, just above freezing, I don't find this likely over a large area or volume. It further reflects the "vaguely possible if everything went just right, but disturbingly improbable" aspect of many proposals regarding Meridiani and liquid water, IMHO. I find it much easier to hypothesize that the vugs represent a more soluble and easily leachable former chloride mineral (or some other diagenetic phase other than Mg-sulfate). Of course, cold temperatures, ice, and Mg-sulfates all seem to be common on Mars, so meridianiite could likewise be common. I'm just not sure if it explains the crystal molds.

For comparison, the photo below shows elongated vugs presumably representing former crystals of gypsum, a slightly soluble evaporitic sulfate mineral, in a matrix of pure quartz sandstone:

Click to view attachment

I took this photo in May, 2003 (well before the Mars rover landings) on a Grand Canyon rafting trip (outcrops just above Deer Creek Falls at Mile 136.3). With my boot for scale, it shows rare crystal molds in the Tapeats Sandstone, interpreted as a 540 million year old beach sand deposit. In this case, some seawater presumably became locally isolated and partly evaporated enough to precipitate gypsum or some other salt, then sand was washed or blew in around the crystals, and then the sand deposit was hardened into rock (by carbonate cementation of the sand grains). The salt crystals dissolved in groundwater at some later time, leaving crystal molds in the sandstone. A similar near-shore evaporitic or sabkha environment was initially deduced for the crystal molds at Meridiani, but has since been modified (to wind-blown sulfate "mudball grains" from a dried up and vanished acid playa lake later soaked in rising and falling, evaporating and flowing brine, if I understand the highly complex proposed scenario correctly).

Regarding the much smaller size of the Victoria Crater "turkey tracks" as compared with those molds initially imaged in Eagle Crater, I wouldn't attach too much significance to this observation. It presumably indicates that whatever conditions favored crystal growth didn't last as long (or were otherwise less favorable) at Victoria. Other than size, the crystal molds look pretty similar. Although they also resemble the elongated crystal molds in my Grand Canyon photo above, logically they can't represent former gypsum, because gypsum is much less soluble than the Mg-sulfates found in the Meridianii matrix. I have no comment on the degree of degradation - even the original vugs in Eagle look pretty degraded to me.

-- HDP Don

A bit off topic (okay, a LOT off topic)...but Don, I think the structures in your picture are the bottoms of the U-shaped burrow Diplocraterion, which are common in both the Tapeats and Bright Angel...

If the structures from Victoria are the the bottoms of U-shaped burrows (and I do NOT think that they are!) then, yowza, we've got a paper to write...
--
Tim Demko

Thanks for all the pans, guys. There was something about that sol 1294 view that looked oddly familiar, and I think I've got it. Compare this pancam view from sol 1294 with this view from the distant past.

Ah, isn't it wonderful that we can look back with nostalgia at images from a mission that's still going?

Hi Tim - Thanks. You might well be right (your specialty, not mine), plus it's been over 4 years since I took the photo, and I've never this particular feature anywhere else in the Canyon. Many exposures of the upper Tapeats, Bright Angel, and Muav are chock full of lovely burrows, I agree, and I've taken hundreds of great photos of typical burrows during several Canyon rafting trips, including during my trip last summer. As I recall, this feature was restricted to a single bedding surface in relatively coarse sandstone, there were no burrows evident elsewhere in the rock (i.e., as seen in section), plus especially some of the elongated cavities appeared to have planar crystal terminations (including one easily seen just above and to the left of my boot-tip in the photo). That, plus the inferred supratidal to subtidal environment, was my basis for inferring that these could represent the exception, traces of inorganic crystals rather than of organic burrows. Still, Mars is far from the only place where digital images can show you just what you're looking for, and if you have a mineral named after you, you're probably looking for crystals. So, probably, guilty as charged, and thanks again.

Occam's Razor would certainly suggest that if you're in a group of rocks that is well known for its burrows, any enigmatic linear cavities that you see just might be related to burrowing, rather than to what you had assumed or hoped they would be (crystal dissolution). By the same token, low pressure, icy Mars is well known to be more than saturated with impact craters, presumably related to the Late Heavy Bombardment, plus numerous later impact events, so might not enigmatic layered, cross-bedded, salty rocks at both rover sites and elsewhere be related to ice and impact cratering rather than to what you had assumed or hoped they would be (warm flowing and standing liquid water, or warm liquid water interacting with hot molten rock)? Well, we've already had that liquid water discussion here, and although Oppy is now in Victoria Crater and Spirit is back on top of Home Plate, little appears to have changed, least of all anyone's opinion.

BTW, I just now looked up Hereford's 1977 article on the Tapeats depositional environment in the Geological Society of America Bulletin (vol. 88, p. 199-211), and he referred to the U-shaped burrows as Corophioides. I presume someone has since changed the name? In any case, Occam's Razor strongly suggests no such burrowers at Meridiani. Too bad. We'll have to write our first joint paper on a less exciting topic.

--HDP Don

Cold fusion? Sorry, couldn't resist.

Here is the view inside Victoria Crater taken with the

R0 Navcam on Sol 1313.

jvandriel

Click to view attachment

Interesting shapes in this one.

Source image: http://qt.exploratorium.edu/mars/opportuni...00P2580R2M1.JPG

Here is the complete view inside Victoria Crater.

Taken on Sol 1313 and Sol 1314 with the Ro Navcam.

Dilo,

stitched with Autostitch and as you can see, no problems.

jvandriel

Click to view attachment

This surely has been quite an eclectic trip over the edge, as seen through many eyes. Thanks to all of you who commented and posted interesting images. I think I'll toss in some right eye false color images.
I don't think there are a lot of fans of these right pancam IR false color images, but I am always on the alert for new sets of R-all images, and even the occasional R-less-than-all sets. As I mentioned before, they seem to highlight certain mineralogies. Here are the most recent right eye false color images from my point of view. Without a doubt, we are well into the section where hematite spherules have formed.
Click to view attachment Click to view attachment

... and in real(ish) colour...

Click to view attachment

Hi,

The two mosaic showing crater interior on Sol 1294



Link to other resolutions

Lenses are so dusty. I become to be so nostalgic about pre-storm pictures .

If Opportunity continued to RAT further into the rock, would it find the minerals, still in place that produce these "vugs" ?

My popular science-level geology take:
The conditions that dissolved the crystals happened long ago
-- before Victoria Crater existed -- and dissolved the crystals
in the entire stratum, not just the current surface.

The "blueberries being formed by current surface conditions"
people may have a different take.

Ant, you did a great work!
I started from these pictures to further equalize contrast/luminosity disuniformities, adding a sharpening too:
Click to view attachment Click to view attachment
(artificial sky in first picture).

Man...she is dusty!!! Really struck by the accumulation on just the one side of the omni antenna mast. One result of this might just be the need to drag a grounding strap like many cars in the southwestern deserts of the US do to prevent occupant shocks when debarking, but in this case it would be to make rovers less electrostatically attractive... ...even though the wheels are metallic, it still seems like adhesion is a major problem after a storm like that.

Might be productive to do a dust deposition survey (insofar as that can be done) on Oppy to look for regions that might have been particularly prone to accumulation for future engineering efforts.

I see, very nice!
I made a polar and two "vertical" projections from your panorama (top right projection is approxmately aligned with rover vertical, bottom one was rotated in order to have a simulated view of the rover from rear/side):
Click to view attachment

Yup, but I think Spirit has it much worse. . They both already have several ultrathin tungsten needles fitted to bleed-off electric charges into the atmosphere.

Based on jvandriel's stitch, here's an artist's enhanced view of the Sol1313-14 panorama.
Enjoy
Astro0
Click to view attachment

Stu.
Great rathole at post 178. The tiny 'stalked' concretions at the far left really bring home to me what 38% gravity and an atmosphere that is a near vacuum really means.

Me? I'm just happy that we're gettng post-storm pictures...!



-the other Doug

Inspired by dilo's polar projections, here's a little artwork I'm calling 'The Little Prince'.
Enjoy
Astro0
Click to view attachment

Just a bit of fun...

Click to view attachment

Wow Astro0, this image is truly awesome...

It certainly is.

Better late than never, here are my attempts at the 1294 ingress survey.



James

Bravo!

Er, could you share your flat-field dust masks? I have "hit the wall" trying to use the pancam sky-flat images to correct for the dust. I have been using the L1 filter to correct the image after RGB conversion.

Here is my final attempt at the north view:

just a bit more fun (with apologies to Stu)

Opportunity looking back at the entry point of Victoria Crater.

The complete view taken with the R1 Pancam on Sol 1299.

jvandriel

Click to view attachment

I don't know how useful this is as I play a few tricks deep within my processing software, but this is my input flat-field:

Click to view attachment

I gave up using the sky-flats as well, the stretching does bad things I think. This is made from some fairly featureless ground pointing pancams in L1 from sol 1290 stacked and blurred. Properly used it should account for vignetting as well.

James

The MI cought some particles moving in a gust of wind on sol 1320.

http://nasa.exploratorium.edu/mars/opportu...ger/2007-10-11/

Particularly:

http://nasa.exploratorium.edu/mars/opportu...00P2956M2M1.JPG
http://nasa.exploratorium.edu/mars/opportu...00P2956M2M1.JPG

(Those two images are about 40 seconds apart)

Today (sol 1321) the rover is expected to be on the move.
Stay tuned.

Pictures are down of the drive.

The rover backed away from the previous site. It seems to be somewhere in between that place (since sol 1305) and the one corresponding to sol 1302.
Check my latest update to the route map.

Beat me to it...!

Click to view attachment