A mosaic of images made between Sol 1305 and Sol 1319

with the R1 Pancam.

jvandriel

Click to view attachment

Here is the result of the Ratting on Sol 1316 by Opportunity.

Taken with the Mi Cam.

jvandriel

Click to view attachment

Sols 1305 to 1319 - L257 - Looking along the bright band.



James

A short Navcam drive movie

Ken,

as you can see in this animation, Opportunitys RAT is still working on Sol 1322.

Taken with the R0 Front Hazcam.

jvandriel

Click to view attachment

Just messing about a bit:

Work volume after the sol 1321 drive.



James

A couple more mosaics.

Sol 1296



and Sol 1298 drive direction



James

We've heard about this already, but here's the official announcement. The rover's have another extension!2009 - I like the sound of that!

Let's hope Steve has an offspring in training to take over the reins!

I just noticed it is now just over 1000 sols since Opportunity drove OUT of Endurance crater. That really puts the length of the mission into perspective - back then, it seemed like the mission had already accomplished so much...

Phil

I just checked the imaging plan for tosol and noticed that the last sequences are from two sols ago. There was nothing planned after sol 1324.
Opportunity has obviously downlinked (old) data during these last two sols so it might be just a "data backlog" issue, like Spirit.

... or it might be something else.

I think the tracking database needs a kick, even with light activity we would still expect to see a few sequences (like Tau) and lots of data is coming down so there doesn't appear to be any problems with Oppy herself.

Me too!!

Click to view attachment

Sol 1299 'Ingress Survey Right' - Looking back up to the entry point.



James

James, your great picture got me thinking again about the power needed to climb back out...

I'm absolutely confident that is not a problem, but I've been wondering about how much more power is needed to drive the rovers uphill versus that needed to go downhill.

Do you, or others, know if this has been covered elsewhere here?

Now... I've got to again express my Thanks to you, and so many others here, for all your efforts that provide so many great color renditions from the data coming back from the rovers. You all make this window into that other world the rovers explore a daily fascination not to be missed!

Well, there is actually a gap on the sequencing, nothing on sols 1325 and 1326:



I would say that's nothing of real concern but only of curiosity; let's see what the next status report tells us.

BTW, the plan for 1327 is of a driving sol and includes also color imaging of Cape Verde and two features named after "Smith" and "Hall". The geologists might tell us who are/were them.

Could they be Asaph Hall, the discoverer of Deimos and Phobos and Jonathan Smith, who, if I recall correctly, speculated that Mars would have two satellites?

Steve M

Obviously, I didn't recall correctly, it's Swift, not Smith.

Steve M

That was Jonathan Swift. There are a lot of Smiths but one was William Smith, author of the first real geological map.

Phil

Sol 1327

Click to view attachment

Here is my attempt with the 360º navcam panorama (left eye) taken after drive on sol 1327.
Click to view attachment

BTW, sol 1329 (today) we might be seeing another move.

On sol 1320 Opportunity captured 10 identically positioned MIs of a recently RATed rock face. Except for the first time interval of 54 seconds, the remaining images in the sequence were captured every 41-42 seconds. Here is an animation of the 10 images, so we can watch bits of dusty RAT cuttings blow about in the local Martian wind. I couldn't create an animation of the full-sized MIs small enough to post here. Since most of the dust mote movement takes place in the unbrushed, inner circle, I cropped the the images to minimize file size.

This set of 10 images was captured over a period of roughly six and a half minutes. The video will replay the observed changes more than 100 times faster than they were actually observed. Apparently it is still windy in Meridiani.
Click to view attachment 676 KB

Hi CS

This is a very good animation it seems show some particals moving one way and then the other and at least one "white" partical appearing out of nowhere. This shows how the higher rate of frames per second in movies would really be useful.
Roy F

Sol 1329: Opportunity moved almost to the lowest part of the "white band" and is now in front of the feature named "Smith".
Is just me or do somebody else see the contact with a deeper layer in this navcam picture?

Yes, Tesheiner, there would seem to be contact with a different layer -- one a little more resistant to weathering, or which weathers in a not-so-uniform way. But -- and this brings up a broader topic -- you don't have to look very hard to see that both are relentlessly layered, almost like the pages of a book, in the typical Meridiani fashion. Pardon my ignorance, but has an explanation been given for the omnipresence and consistency of this layering?

I didn't realize before seen this picture that the capes at the far side are lower than the horizon.

Opportunity shot this panorama on sol 1329.
Click to view attachment

Here is a view of 'Cape Verde' from Sol 1329.

Click to view attachment

The layers above this line appear roughly parallel to the layers below it. Could it be a fault?
Click to view attachment

[quote name='alan' post='102552' date='Oct 22 2007, 12:57 PM']The layers above this line appear roughly parallel to the layers below it. Could it be a fault?

We saw an oblique feature at Cape Desire that seemed to have the layering pass continuously through it. Some post-depositional processes were discussed, including concretions formed along cracks. On the other hand Cape Verde does look superficially as if it has undergone some slumping relative to nearby capes. It will be fascinating to see if close-up observations here can make a definite distinction between altered cracks and genuine faulting involving post-depositional relative motion.

Still one of my favourite views from the whole MER mission...

Click to view attachment

Looks like one of those face-in-profile-in-a-cliff type things

Doug

For some unknown reason my dust flatfield doesn't seem to work on the right-most image so this isn't very good, but anyway...

Cape Verde - Sol 1329.



James

Here is my view of the Sol 1327 panorama.

Taken with the R0 Navcam.

jvandriel

Click to view attachment

Ahem. So I guess we have now begun our first official transect down the Duck Bay exposure, and ought to begin the 'geologizing' from the top down:Click to view attachment
From what we've seen so far, I'd hazard to propose that we have crossed at least two distinct 'units' (A&B), and have close proximity to two more (C&D)
A constitutes the 'ejecta', a layer of jumbled blocks implaced ballistically by the VC impact, a breccia with more-or-less randomly oriented 'clasts'.
There may be some substructure in Unit A, but we are apparently deferring that study for later.

Unit B appears to be the first in situ component of the pre-impact strata. Fractured, as might be expected, but far from random in the orientation of the Meridiani laminations. There does not seem to be a pristine, flat original surface upon which the ejecta is piled, nor would I have expected one. This close to the center of impact, the energy of the fireball should have stripped off much of the original surface and dispersed it well away from the crater.
This may explain the absence of a distinct "concretion-free" upper layer, as can be found farther away from the crater. The sites in B that we have observed closely with the IDD (#8700 and 8736) show a range of small-scale 'berries' and vugs in the rock such as we have seen on the drive south to VC.

Unit C is distinct from B in its appearance, having much more smoothly-eroded, coplanar blocks that give it the "bright ring" albedo, in contrast to B and D. Whether its microstructure and composition are similarly distinct awaits the result of IDD analyses. Does the smoothness of its appearance imply a softer rock, more prone to erosion than the units above and below?

Anyway, true or otherwise, this prelude sets the ball rolling, and I would hope that the rockhounds in our membership leap to the fore with corrections and additions as we continue Paolo's Plunge.

Fascinating detail visible in the "band" now...

Click to view attachment

Several explanations, among them 1) an exceedingly complex interplay among acid brine evaporation, wind erosion and deposition, varying groundwater tables, surficial flowing water, and concretion secretion (official team explanation, applied only to Meridiani), 2) volcanic surge with subsequent fumarolic activity (McCollom and Hynek's explanation for Meridiani, later adapted as the official team explanation for the Home Plate area in Gusev - but not Meridiani), and 3) impact surge owing to planetwide intense cratering of the Late Heavy Bombardment (Knauth et al.'s explanation for both Meridiani and, when it was discovered, Home Plate; could account for similar layered rocks anywhere else on Mars). The detailed consistency of the layers in the Meridiani region probably has not yet been adequately tested. It's general aspect, including the dominance of shallow cross-beds, presence of tiny spherules, and saltiness, seems fairly consistent, as far as can be told from observations to date. I was second author of the Knauth et al. paper, as most here know.

-- HDP Don

Thanks, dburt. I will have to study the Knauth paper. In the interim, I would note that such consistent layers on earth are often associated with annual processes, for example, tree ring layering. (Just an impression from looking at the Meridiani layering . . .)

Here is a polar projection of that same shot. North is up.
Click to view attachment

An impression many others here, including me, have shared. A subtle but important distinction is that tree ring-type sedimentary layers, or "varves" to the sedimentologist (annual layers in a periglacial lake that was frozen over every winter and thawed every summer) are not cross-bedded. That is, they were not being eroded (scoured) at the same time they were being deposited. This is impossible in the standing water of a lake, and suggests a more dynamic environment of deposition.

-- HDP Don

Dburt,

One of the arguments against the JPL model with cyclical deposition of sediment by surface water flow is that the warmer, wetter period required would have had to occur when solar output was less than the present levels. Under that scenario, even with a thicker atmosphere Mars would be frozen and surface water would be transient, formed as a result of volcanic or impact energy. But your reference to the late heavy bombardment has raised a hypothetical in my mind.

If Robin Canup’s model of the creation of the moon as the result of a Mars sized body impacting the Earth is correct, (and I am not saying that this is proven), then Earth was extremely fortunate. The creation of the Earth/ Moon duality provided a stability in Earth’s obliquity to orbit providing a reasonably benign environment for the development of complex organisms. But what if Mars was less fortunate and experienced a near miss with a similar sized object where the geometry of the encounter resulted in Mars gaining angular momentum at the expense of the body. (A reverse slingshot effect if you would). Following such an encounter Mars would have migrated outward towards the edge of the goldilocks zone and the late heavy bombardment would have been the coup de grace.

I only mention this hypothetical (or perhaps fantasy is a more appropriate descrription ) to make the point that we need to keep an open mind on the early surface conditions of Mars. Impact events certainly had a huge influence on Martian geological development and would have contributed to both Gusev and Meridiani. But cyclical aeolian or water driven events appear to be a key influence at Meridiani while aeolian and hydrothermal influences seem to have been major contributors to the home plate area.

Aussie - Not impossible, but as stated in previous posts, I have problems with both scenarios, the most obvious one of which ("the elephant in the living room") is that the two sets of rocks appear so very similiar - ferric acid sulfates, spherules, and especially bedding features. It just doesn't seem logical to ascribe them to completely different causes. Granted that the rocks differ in minor details, and that the wind moves particles around on modern Mars, but it's unclear to me what process can then cement these particles uniformly into a rock (given that significant burial is unlikely). Impact cratering is a process that likewise continues to be active on modern Mars, and uniform cementation is not a problem for steamy surge cloud condensation (cf. the famous young rampart craters of Mars). Furthermore, the surge clouds probably contain a large component of sand and dust particles scoured from the substrate (scouring is also indicated by the low angle crossbeds). A feature suggestive of surge cloud condensation is deposition of beds with original dip, and such steeply inclined beds seem common in and around Home Plate. Evidence of hydrothermal activity around Home Plate is equivocal at best - so far no veining, no hydrous clay minerals that might be expected from basalt alteration, no alteration mounds or haloes of any kind. Evidence of water immersion or water flow at Meridiani is likewise equivocal at best, as discussed in many previous posts. Meridiani bedded rocks have clearly been reworked many times by impacts, as seen at Victoria Crater itself. Future rover observations at both landing sites are eagerly awaited.

-- HDP Don

I'm not sure if attention was drawn to your abstract for the 10th mars Crater Consortium meeting, and its kind acknowlegement of UMSF discussions.
http://www.marscraterconsortium.nau.edu/BurtMCC10.pdf

Aussie - Thanks for posting the link. In that abstract I tried to summarize discussions I had here, so I thought the UMSF acknowledgement was appropriate.

Although my talk on impact surge deposition seemed to go over well (perhaps not surprising, given the interests of the audience), more than one participant cautioned me afterwards to be careful about generalizing from layered rocks at the two rover landing sites to those on the rest of Mars. That caution was also appropriate.

-- HDP Don

I read the abstract and found it interesting. However, it prompted a question which is "How large an area could a single surge deposit be expected to cover?".

My reason for asking the question is that I have previously read that 3 distinct units are present in the wall of Endurance crater: cross bedded deposits, flat bedded deposits and deposits containing distinct structures which may be festoons.

These same three units seem also to be present in the wall of Victoria crater which is 10 km from Endurance crater. Is it reasonable that if the origin of any of these distinct units is a single impact surge deposit covering an area several km in diameter?

New Opportunity images from sols 1329-1334 became available at the Exploratorium a little over an hour ago.

Paul.
It is not the area but rather the depth that makes me query surge deposition. Extrapolating from Endurance we can assume that the apparent sandstone layers at Victoria, which I believe evidence some steep cross bedding, will have 'berries' throughout. Repeated impact events all producing hematite spherules through mechanical accretion in high temperature surge clouds does not sit comfortably - particularly with Tim Glotch's take on the spheres: My view on the hematite formation at Meridiani can be summed up thusly: thermal IR data from TES and Mini-TES rule out a high-temperature formation mechanism Post 49 of Mars/Surficial berries thread. http://www.unmannedspaceflight.com/index.p...=4391&st=45

HP Don makes some strong points and I have no doubt that some layers will indeed be surge deposits. Hopefully Oppy will delve deeper below the band and perhaps finally set some questions to rest. It would be a pity if Paolo's Plunge became a toe dip.

Aussie - In response to PaulM's original question, the area covered by an impact surge would depend on the mass and competence of the impactor, its incoming velocity, and the competence and volatile content of the target (in addition to the density of the atmosphere, etc.). For a large enough crater, it could span many hundreds or even thousands of kilometers (especially if surges caused by secondary impacts are considered). Individual surge deposits may indeed be relatively thin, except near the source, but collectively (e.g., if formed during the Late Heavy Bombardment) they could span many hundreds of meters in thickness in any given area. Although energetic surges can easily override topographic obstacles, the deposits tend to be thicker and somewhat coarser in original topographic lows (such as inside a preexisting crater).

Steep cross-bedding (including dune forms), shallow cross-bedding, flat bedding, and apparently even "festoons" can characterize different depositional regimes (including "wet" vs. "dry") in surge deposits (see many earlier discussions), although shallow cross-bedding is most typical. Thus these heterogeneous particulate flows can mimic many bedforms produced by wind or water deposition.

As discussed in earlier posts, you need only to produce the hematitic berries once during a single unusual impact event - they appear to be competent enough to withstand reworking and redistribution by later impacts (which could easily have spread them out over a wider area). This is clearly seen by the distribution of impact-excavated berries around Victoria Crater. The thread you cite mainly concerns whether or not Mars hematite formed by oxidation of magnetite, and on the nature of hematite at Gusev. When Tim Glotch says, in the post you cite, "This implies that the hematite there is not coarsely crystalline like it is at Meridiani" he is apparently acknowledging that the blue-gray Meridiani hematite is coarse-grained (specularite) that normally is only produced by high temperature hydrothermal (or fumarolic) processes - such as those that might be expected in a surge cloud. (Pre-landing ideas had the specular hematite produced in a giant hot spring or via metamorphism of an iron formation.) His high temperature experiments, as I recall, dealt with simple dry roasting - irrelevant in this case, where we are talking about steamy or hydrothermal conditions. Sometimes it pays to refer back to the original papers. Anyone who seriously believes that typical hematitic sedimentary concretions consist of blue-gray specular hematite (and that they are strictly spherical, strictly size-limited, uniformly distributed in their parent rock, and never clumped together into large masses) perhaps needs to do more geological field work.

Not wishing to repeat myself any more, I somewhat hesitantly refer you back to this extremely lengthy earlier thread (and the links and references therein):
http://www.unmannedspaceflight.com/index.php?showtopic=4308

--HDP Don

Any ideas how many meters Oppy has driven into the crater so far?
I know the science target bright band of rocks is about 12 meters (about 40 feet) from the rim...

Everything that can be said about impact surges is over here.

This discussion is about Paolo's plunge. Now back to our regularly scheduled postings.