I hope you are right about the easterly path being easier, Doug, but I would be less optinistic about it!

I personally don't anticipate such long distance driving. I expect to see relatively slow movement across the etched terrain, hoping for a serendipitous new exposure, maybe going slightly up or down the section. Westwards just a few km lies a very eroded large craterlike depression. Southwards or southeastwards maybe just more etched terrain, but always a chance of a particularly good exposure with different blueberry concentrations or festoons or whatever.

Long distance extended mission planning wasn't part of the site selection process for MER, because drives of only 1 or 2 km were anticipated and the landing site was uncertain by tens of km. But I think we can expect that MSL and ExoMars site selection will include assessments of good extended mission opportunities - in fact we can see that in the MSL workshop presentations.

Phil

I seem to recall that there was some interesting-looking object sticking up to the east as Opportunity headed south from Endurance. This would provide a better chance to have a look at that as well.

Can u please show me this interesting object if you dont mind

That would be the rim mountains of Ithaca crater. As I recall, at one point we were seeing the northern rim, and later we saw the western rim; the rim is largely degraded.

Were you referring to the dark patch way back before Opportunity encountered any dunes? There was some discussion of whether this could be the cruise stage impact (and I have no opinion with regard to that).

HiRISE has cleared that up quite a lot (greyscale, 100%)

Also attached - the Heatshield in IGB at 200%

Any estimates as to how deep the "fresh crater" is? What would we learn from it that we haven't gotten from a fresher impact, for example where the heatshield impacted?

I remember it as a dark object sticking up on or near the horizon, almost due east as Opportunity was going from Endurance to Erebus. But I've just gone through dozens of images from that period, and I can't find it now. Sorry.

Are you referring to the bump on the horizon that kept being mistaken for Victoria? I believe it was to the west.

Perhaps you're referring to the rim of "Ithaca", as algorimancer suggested, which was visible to the east as we approached Victoria:

http://marsrovers.jpl.nasa.gov/gallery/all...ZTP2293L7M1.JPG

No, it looked more like one of those rocks in the middle ground in that image, though much farther away. Unless I was hallucinating....

A quick insight from Jim Bell on this "After Victoria" issue at spacEurope:

"A few people on the team, like Tim Parker, have been making and looking at images like yours of more distant craters.
If we are fortunate enough to continue to be alive once we reach a consensus that we are "done" in Victoria, then these are certainly some of the juiciest potential next targets!"

I like juicy stuff...

Speaking of juicy...there's also a new book on the way...

Wow! Thanks for the heads-up on Jim Bell's appearance in your blog, ustrax. I was happy to learn that the team has not ruled out "juicy" targets far away, and also that they have not yet tired of Victoria's nearby secrets.

Some of us have been eagerly anticipating Jim's 3D book, so thanks also for that update. Congratulations. Your blog has become required reading.

(Echoes of thanks to ustrax for his blog)

From Jim Bell's statement:



I've been wondering about Verde looming larger, and whether it wouldn't be more prudent to head the other way for survival's sake as the rover would be angled more towards the sun.

No Contesto, Sahib! Verde is wreathed in shadow. Cp Verde PM view
Even in the afternoon.
Frio, on the other hand, is mostly illuminated through the day: Cabo Frio PM view
AND there's deeper exposures there.

no brainer

The slumped promentary in the background looks interesting. Anticlockwise around Victoria seems a reasonable way to spend the next year or so.

It is a cool promontory. Better view here.

I found this comment interesting:Many more months. I take that to mean they have decided it is safe to drive in deeper, and we won't be leaving soon. Or perhaps they will backtrack upslope and reexamine the upper layers in more detail? This sounds a bit funny, since we heard from Squyres recently that he was concerned about wheels and was getting anxious to get out.

In that image it also looks like there is a sheet of sand between us and Cabo Frio.

Yes, that's the case toward either cape. The question to be addressed is whether the sand slide is traversable. There is cause for concern in light of the deep scuff marks made by Oppy in the sand between two of the rock slabs a while ago. If close inspection suggests that we can't cross those areas, we will have to go back up Duck Bay at least as far as the bright ring to circle around to Frio. That will take a while, but it's time we have.
As to the "collapsed cape" beyond Frio, I don't see the appeal of an area that probably has it's deepest layers buried under the collapse.
Deeper is better. Frio is better unless its slope is too great.

I'll try to improve in the future...
Until then I can't avoid to see Victoria's exploration as the prelude to somehting bigger...even if we spent here an another year...I am that trusty on Oppy...

Slightly off-topic, and just a short question. Does Postcards from Mars include pictures from Victoria Crater?

No, it doesn't. The book went into its first printing in November of 2006, shortly after Opportunity arrived at Victoria

Thanks for the reply. So, I think I'll wait for the book they'll publish when the rovers are no more...

You'll be 274 years old by then...

Oups, sorry Ted, I could not resist

LOL

From TPS's April 30, 2008 Rover Report, Steve Squyres says:




As a "Big Crater" fan, I'm excited to hear these words!

Of course that is either a mis-quote or a slip by Steve, the Mini-TES is both inoperable and not located on the IDD (which was what Steve was talking about at the time)

Listening SS on the TPS interview I've realized that we can now say that the size of the lake/sea at Meridiani was at least 6 km big in the direction Endurance-Victoria. SS said that they've found basicaly the same stuff in both crater.
So, one advantage, getting to Ithaca, will be to extend this ground proof both in a second dimension and in size.

Given Oppy's demonstrated progress on getting to a cliff face a few meters away, does anyone still believe Ithaca is a realistic goal? Something always happens to interfere with those hoped for 100m a day drives. It's a given. Both Oppy and Spirit have given us their "miracle miles" by getting to Victoria and the summit of Husband Hill. I don't hold out hope for any more. It's basic neighbourhood poking around from here till the end, IMO.

Brian

I'm with you, Brian - with regards to the rovers I can't help feeling that "old car feeling" you get when, a few years into car ownership, once the novelty and the new smell have long worn off, and the odometer has passed the 100k miles mark, you find that the central locking starts gumming up, bulbs pop with increasing frequency, and there's a mysterious rattle which only occurs on cold mornings.

I love the rovers to pieces, but surely we're at the point where we'd just about trust them on a trip to the shops but not an 80mph burn down the M6...

Andy

Don't forget we're sitting on a sandy, 20 degree slope at the moment! I'm sure Oppy could manage a few more "burns down the motorway" once we get out onto the smooth, flat annulus outside Victoria...

It doesn't always mean the end...my car is a few miles short of 200,000, and until it needs something big beyond routine maintenance, I see no point in replacing it. I hope Oppy and Spirit have its longevity.

I'm with you Ted.

Climber - "Basically the same stuff" in both craters does not mean there was a lake/sea there, because the sediments are clearly not lake or sea beds. They are cross-bedded, obviously transported sediments, derived from some place else via either wind transport (according to SS et al.) or via impact reworking (according to Knauth et al.).

Regarding the later discussion, I still drive (and abuse) a 1985 4WD pickup truck with its original engine and transmission. It had 7 years and 100 k+ miles on it when I bought it. I love that go-anywhere vehicle, even though it has developed some obvious quirks and rattles with age. So don't write 4-year old Oppy off yet.

-- HDP Don

Thanks for your correction Don. I thought I understood this from SS interview but I understand now that I was wrong.

Re "old vehicules", Oppy's even a 6WD and I'm gald your "on board" for the BIG drive

I think SS was not just referring to the extent of transported sediment deposits. He was also referring to the extent of ground water action upon those deposits.

That remains to be demonstrated, IMHO. Certainly near both craters (Endurance and Victoria, and all across Meridiani Planum, based on orbital images) there is a salty high-albedo layer (efflorescence-like?) near the surface, beneath a lag deposit of "gray" hematitic spherules. This more likely demonstrates a long-lived wind erosion/evaporation/frost leaching/weathering surface rather than a particular hypothetical groundwater table. There are tiny spherules in some layers at both sites (and in a particular layer stratigraphically beneath Home Plate in Gusev Crater) - again, not necessarily owing to groundwater, if the spherules formed via impact explosions and steam condensation (volcanic explosions and steam condensation have been interpreted by SS et al. as forming Gusev spherules). Everything is cross-bedded, mainly at low angles, which feature might be expected via either the wind/water or impact surge hypothesis, but the layers have not been correlated, and nearly identical cross-bedding is exposed in Home Plate in Gusev Crater (albeit interpreted as caused by volcanic steam explosions, with possibly a late wind contribution). Although some festoon-like features have been noted here at UMSF in the middle of Victoria Cliff exposures, none have been officially remarked upon, AFAIK - in fact, the interpretation has been made that that the sections do not correlate, because the Endurance section (with larger spherules and the alleged festoons) must lie buried beneath the section exposed around the rim of Victoria. This section has been interpreted as entirely eolian (wind-deposited), despite its apparent "festoons". Impact excavation (i.e., impact reworking) is interpreted to have dug up the large spherules seen around the rim of Victoria. Of course, we interpret the bedding features too (in fact, all exposures studied by both rovers) as possibly representing impact reworking, on a very much larger scale, with much participation of water, on both sides of Mars, but that is definitely not the official story of SS et al. (at least, not yet ).

And so on. Considerable confusion, some inconsistencies, but apparently not (AFAIK) a demonstrated stratigraphic correlation Endurance Crater to Victoria Crater, except in a very general way. Not wishing to repeat old arguments, I'll leave it at that.

-- HDP Don

Please do. We have been through this at significant length before.

Although I was the one who originally suggested the possibility of festoons in Victoria exposures, I am now convinced there are none here. If the MER team thought they saw any, you can be sure they would have made detailed observations of the suspects. Lacking a stratigraphic succession similar to that observed in the Eagle, Endurance, and Erebus sections, it would be difficult to suggest anything more than a very general stratigraphic correlation between the northern and southern observed sections.

There are still the geochemical/diagenetic contacts to consider. There is no reason to assume that they would be parallel to the stratigraphic contacts.

This robotic geologic exploration is fascinating, is it not? I must suspect that a human geologist in the field on Mars would have resolved many of these questions in a day or two.

Yes but, but, but, 2 human geologists would have resolved them in 2 completely different ways! And what about a committee of 30 reward-seeking "experts" constantly jostling one another at the outcrop? You can convince yourself of whatever you need to, and so can I, and so could Lowell, and so can a committee or a jury or the US Congress, but that doesn't make the result a "resolution" in the scientific sense. Knowing that, I try to convince myself of absolutely nothing (and not to allow anyone else to convince me of anything), and then I explore what is demanded by actual observations, logic, and Occam's razor. That doesn't mean that I'm necessarily right - only that I'm a scientist.

-- HDP Don

I love this !

Yeah...objectivity, what a concept. Give 'em hell, HDP!

Yeah, yeah, yeah...but sometimes the two geologists, the committee, the jury, and congress will all come to the same conclusion. Sometimes the conclusion is obvious to the most casual observer.

CR - I don't want to touch that one with a 50 foot pole, unless you provide some concrete examples. Mars examples would be especially helpful, and might even keep us on track. Of course, I'm tempted to say, "like the perfectly obvious conclusion that a dropped boulder on Mars will fall appreciably faster than dropped pebble?" A majority in Congress and on most U.S. juries might agree on that one (not to mention a few geologists I know ).

-- HDP Don

This link may help convince those geologists:

http://nssdc.gsfc.nasa.gov/planetary/lunar...ather_drop.html

I'm not sure why you wouldn't. I wasn't suggesting anything controversial, political, or otherwise inappropriate for discussion here. I think I can provide some concrete examples, and Mars has some good ones. Your example of a "perfectly obvious conlusion" might fool many of our politicians, but it doesn't work in a debate among scientists familiar with the basic laws of physics. My favorite question along those lines is, "Which weighs more, a pound of feathers, or a pound of lead."

Of course any two geologists might disagree on the interpretation of a particular geological environment, but if you ask 100 geologists, most likely a majority of them will settle around one or two (or a few) favored interpretations. I'm not suggesting that the majority is always correct, but the majority often is. When people discuss scientific interpretations, Occam's razor is often quoted. But one version of Occam's razor; the one that I favor, is, "Everything should be explained as simply as possible, but not more simply."

The unmanned/robotic exploration of Mars can offer some examples, because the orbiting spacecrafts, landers, and rovers each have a limited number of analytical instuments. Id est, the information they can send back to us for interpretation is limited, and usually less than ideal. A rock formation on earth can be mapped and sampled in detail, and analyzed by a full array of techniques here on Earth, but that's not an option on Mars, yet. That is why many scientists favor sample-return missions and the manned exploration of Mars.

For example, I understand that the early remote sensing orbiter exploration of Mars detected very similar spectral signatures all across the planet. The simplest version of Occam's razor would dictate that scientists should have concluded that the entire surface of the planet was of the same composition. We now know that is not the case, and that the globally distributed dust coating the entire surface is biasing the remotely sensed data.

The rovers on the ground have helped us study and understand that phenomenon, and have raised other questions. In another example, we have all seen pictures of spherical features in rocks on opposite sides of the planet through the eyes of Opportunity and Spirit. What if the rovers only had simple cameras, and no other analytical tools? As geologists, we know that spherical structures of various origins are common in terrestrial rocks. But now we are on Mars, so the most simplistic interpretation of Occam's razor might require us to assume that spherical structures in thinly layered rocks were created by the same processes across the planet. Fortunately for us, the rovers do have some additional analytical instruments that have demonstrated that the spherical objects have different compositions and microscopic features.

I am only saying that robotic, planetary exploration is more challenging than many would suspect.

CR - I certainly agree with your final statement! My main point was to disagree with your earlier implication that having one or a bunch of scientist-astronauts jostling each other on the Mars outcrops (with all anxious to show off their erudition in front of the cameras) would necessarily eliminate most scientific controversy. Also, inasmuch as you brought it up, I feel obligated to point out that if different spherules have different compositions or appearances on different sides of Mars, this doesn't necessarily indicate different origins. That is, concretions alone have hugely varying compositions and appearances (e.g., silica, carbonate, oxide, hydroxide) and sizes and shapes (only rarely are they perfectly spherical; most commonly they are nodular and clumped together), and impact-related spherules, etc. likewise have many different (generally small) sizes and compositions (e.g., glassy tektite "splash droplets" vs. spherical glassy condensates vs. spherical accretionary lapilli formed as a result of sticky steam condensation on various particles).

I generally prefer Einstein's formulation of Occam's razor (the simplest hypothesis that accounts for ALL of the observations - equivalent to your "and no simpler"). For that reason about a year ago I asked anyone on this site to suggest Meridiani features NOT explained by the impact hypothesis - given that the extant highly complex watery scheme actually fails to account for many features, including many features of the spherules themselves (e.g., the gray or specular hematite, size limitation, shape limitation, general clumping failure, and distribution in the rock). FWIW, that original request remains unfulfilled. (Note: I respect Doug's eventual decision to cut off the pointlessly repetitive and emotional discussion that followed, and don't wish to restart it now). Thanks for your intelligent input.

-- HDP Don

Not wishing too hard eh? It restarted. Three posts deleted.

Seriously - not again.

On a number of occasions Steve Squyers has expressed an interest in looking at cobbles on the plains after Oppy is finished with Victoria. I guess that his reason is that there is not much variety in the rocks of Meridiani and so the opportunity for Oppy to look at more meteorites and rocks from elsewhere on Mars (such as "Bounce") is attractive.

I think that Oppy's first scientific target after it has left Victoria will be a rock close to Beagle crater described in the following Opportunity Update:

"Sol 875: On this sol, the rover successfully backed away from the ripple that saw 80 percent slip on sol 873. Opportunity used its panoramic camera and miniature thermal emission spectrometer on a distant potential meteorite; those instruments also completed an observation of the sky and ground."

There are nice color and false color photos of this rock in the following post:

http://www.unmannedspaceflight.com/index.p...ost&p=61844

The following map shows the general area that Oppy was in in SOL 875:

http://www.unmannedspaceflight.com/index.p...ost&id=7283

At that time I saw this extensive area of pavement just to the North West of Victoria's ejecta blanket as possibly of interest. An unwillingness to drive Oppy too far with its arm extended might add to the attractiveness of this area.

Reading Stu's lovely epitaph for the exploration of Victoria, I started wondering what benefit there might be to retracing most of Oppy's path thus far. There must be plenty of known targets bypassed in favor of proceeding to Victoria. And how cool would it be to get back close to square one several years after landing? How do the tracks from the early sols look after a global dust storm and several martian years of wind?

Is that what mission planners favor at this point?