Don't they? I am *especially* interested in the one I designated C -- its basic form is that of a dimple, rather than a bowl. The light floor unit *might* be some simple dust fill, but as it is surrounded by a "crater" wall that appears convex rather than concave, I have a hard time believing that this is an impact structure, and if it's a sinkhole, the floor might represent a *much* lower evaporite unit than we've seen before. The dark source of the small dark fan *might* just be a dust trap that occasionally yields part of its trove back up to the winds -- but it might also be a piece of a darker, different type of material that's eroding into dark dust.

Yes, Ithaca's ringwall remnants could be quite interesting -- but what are the odds that Ithaca was emplaced a *long* time before this part of Mars was repeatedly flooded, and has been altered so much that you'd have to spend a decade putting together it's story? Ithaca *might* give you some insight into what existed here before there was water -- the three craters I'm looking at, it seems to me, might offer a better chance at increasing our insight into what this part of Mars was like *while* there was water here.

Is it just me, or does it seem like that would be perhaps a little more useful?

-the other Doug

OK -- if we're seriously going to discuss where Oppy ought to go after Victoria, I must say I like Fred's idea of heading NW to get back onto the flat, almost-ripple-free terrain that lies beyond the northern extent of Victoria's apron. However, no matter what we do, we run into bad ripple/dune terrain trying to get to Ithaca.

I'd like to suggest a different set of targets. There are three craters of apparently wildly varying ages off to the east-northeast that would make a good site for a co-ordinated study set, which might only take a year or so of traveling to reach (assuming no further wheel malfunctions and the ability to travel 200+ meters a day on good "roads"). Here's my suggestion, overlain on Ustrax's regional map:



My proposed route is in blue, here. (Pardon the crudity, I really only have MS Paint with which to work.) Granted, it's nearly as long a traverse as getting to Ithaca, but it traverses over better, far less dangerous terrain, and I see three very interesting targets sort of grouped together at the end of the journey.

The first target to be reached I have labeled A. A is an old, degraded crater about 70% the size of Victoria. It has very much the size and appearance of Erebus, except that is is surrounded not by the etched terrain (which we know now is heavily covered with soft ripples), but with the flatter pavement we found near the landing site. It's an ancient crater, really just a ring of exposed evaporite rim material around a complete crater fill. But unlike Erebus, it's not covered over with obscuring layers of ripples. It seems to me that anything we could investigate at Erebus, we could likely investigate at A.

Just beyond A lies B, a crater roughly the same size as Victoria but with a less obvious apron and without the bay-and-cape structures. Taking a close look at B could answer some significant questions as to why Victoria has developed cape-and-bay structures, while B hasn't -- is it due to differences in the target rock, or is it differences in the erosional process?

Finally, just past B, we have C, which is almost more of an albedo feature than a crater. This one *might* not even be an impact structure -- it's roughly the same size as Victoria and B, but completely lacks a raised rim. Even when an impact structure is completely filled in this area, it leaves a ring of exposed evaporite rim deposits, but C doesn't show any signs of that. It appears to be a sinkhole more than a crater, and seems to be a source of dark dust that is swept out of C and up to the north-northwest. A sinkhole roughly the size of Victoria could teach us an *awful* lot about the subsurface structure of the entire region.

I find nowhere else within possible range where we can see such a diverse set of observation targets, and which can all be studied one after another with relative ease. Each has its own telltale signs of origin and history, and each appears to have undergone significantly different origins and erosional processes -- which is quite interesting, since they're all in fairly close proximity to each other. A study of all three features would, IMHO, give us a far better idea of what processes formed this entire area than looking at the very much more highly shocked remnants of the much larger impact that formed Ithaca. Each also provides variations on what we have already learned at Endurance, Erebus and Victoria, which should help us put those findings in a better regional context.

So -- not only do I see a good set of targets, I see a set of targets that are both easier to reach and at least as valuable to study as Ithaca would be.

What do y'all think?

-the other Doug

There has not been a specific site pinpointed, but it's likely that the landings will be near the permanently sunlit portion of the rim of Shackleton Crater. The Moon's south pole is located within that crater.

What's not been decided is whether the first LSAM landing will occur on a permanently sunlit site, a permanently shadowed site (to allow water ice mining operations), or a site which sees both day and night. My understanding is that the portion of Shackleton's rim that is permanently sunlit is probably not suitable for building an outpost; it's basically a ring-mountain peak, with no large stretches of contiguous flat land. However, a landing site with access to those sun-drenched peaks (either in Shackleton's floor or just outside the crater) might allow a solar power station to be emplaced up there, with power transmitted back to the outpost by either by land-lines or by microwave transmission.

So, the first landing will probably either be just outside Shackleton, or just inside of it. I tend to think just outside, because of the engineering challenges of operating an outpost at a place that never gets sunlight. The thermal considerations alone are daunting. I'd bet they'll land automated ice mining equipment in the permanently shadowed locations and then emplace water pipelines from there that lead to the outpost. At least, that's how I'd do it.

-the other Doug

I think we should look at the entirety of Steve's quote:



That statement doesn't necessarily mean that Steve thinks they'll be done at Victoria after they're done with Duck Bay. It just means that after they get everything they can from Duck Bay, they're planning on continuing with more observations -- in other words, they're not planning on entering at Duck Bay and ending the mission there. (I take that to mean that if they don't think they can get out, they won't go in. That's reinforced by the mention of a "careful safety review.")

Victoria has a lot more to offer, even after Duck Bay is explored. They've only traversed a third of the crater rim, after all, and there are interesting features counter-clockwise from Duck Bay, such as Bright (nee Sofi) crater and the apparently soil-stripped capes. There are also the Suspiciously Linear Features (SLFs) (take a bow, VP) in the east and southeast walls and floor.

Going forward doesn't necessarily mean leaving Victoria. There are many more things in and around Victoria they can (and likely will) take close looks at after they're done with Duck Bay.

-the other Doug

No, that word references the dynamics of ethical systems. Athodynamics references the dynamics of one of the Three Musketeers...



I think the proper term would be ethanodynamics.

-the other Doug

EC, you have discovered a brand-new, never-before-seen object orbiting Saturn!

Since you discovered it, you get to name it. Might I suggest Oldladyglasses?



-the other Doug

Yes, that's the Surveyor in that pan. I've only seen two images of the Surveyor Crater, which include the Surveyor, taken from the LM landing site, both taken during EVA-1 pans. The one you linked is the better of the two, you can actually make out not only the solar panel and antenna (which were in sunlight), but also the triangular shape of the landing gear structure. The Sun was only about 5 or 6 degrees above the horizon during Apollo 12's first EVA, so the shadow of the crater rim fell about one-third of the way down Surveyor's antenna/solar panel mast.

The other image, from approximately the same perspective, was taken with a higher F-stop and the shadowed portion of the crater shows much less detail. In that picture, only the solar panel and antenna are visible, you can't see anything of the landing gear structure.

Of course, the human eye has a much greater dynamic range than the film stock used during Apollo (or any film stock, for that matter). When Pete Conrad took three steps to clear the LM and look back into the Surveyor Crater, just after he stepped onto the surface, he could clearly see the entire probe, even though most of it was in shadow. (It was illuminated by light backscattered from the opposite, sunlit crater wall.) That's why he cackled, almost immediately after setting foot on the surface, "Guess what I see sitting on the side of that crater?"

-the other Doug

For some reason, especially since I haven't seen a final complete design and the experiment suite has not been finalized (as far as the last I've heard), it just occurs to me that maybe I ought not assume that MSL is going to fly on time. But, hey -- if they have all the cash they need, I should stop worrying and learn to love the Bomb... *grin*...

-the other Doug

Actually, the apparent tilt of Intrepid is an illusion because of its proximity to the edge of the scene. Even the best lenses can introduce distortions near the edge of the scene.

According to every other source (including the LM's guidance system), Intrepid landed almost completely flat, almost no pitch and roll excursions. The landing point was indeed only about 5 meters beyond the lip of the Surveyor crater, and had Pete landed her just a little bit shorter than he did, she would have ended up on a significant slope. As it was, there was barely room for unloading the ALSEP.

But yes, these pans do give a very good comparison to the Surveyor pans. Especially nice is the detail it shows in Block Crater... very nice. Thanks for finding these, Phil!

-the other Doug

I don't know -- while the 17 site was set up (at only minor effort) with long-term exposure study in mind, it's not the best place from which to stage more extensive exploration. The scarp terrain at the western mouth of the valley isn't all that easy to drive over (just ask Gene Cernan), and there are a number of rilles and graben beyond which tend to cut off long-ranigng exploration.

If I were going to land and do some decently long excursions, I would likely land somewhere other than Taurus-Littrow. And I would definitely NOT land at 15's Hadley site -- that's a valley that is completely cut off by mountains on three sides and a rille on the fourth.

-the other Doug

We all know that MRO uses a backup S-band transmitter from the MER program, which operates on the same frequency as one of the MERs (Oppy, IIRC). No one thought there could possibly be a conflict, since MRO was not going to arrive at Mars until more than three years after the MERs, and of course the MERs would have definitely ceased functioning by then...

Now they have to plan use of the MER DTE system and MRO's data link more carefully than otherwise, because of this conflict that no one thought could ever have happened.

MSL is launching in two years (at least supposedly), and while one might make the assumption that the MERs will definitely be dead by then, the time between now and MSL landing is less than the time between the MER landings and now.

Do we know for certain that MSL is being designed such that there will be no conflicts of any kind with the MERs, if either or both Spirit and Opportunity are still functioning when it arrives? There aren't any more spare S-band transmitters from the MER program that MSL is planning on using, are there...?

Just curious...

-the other Doug

I don't know how effectively Spirit can do that with her RAT worn out. Brushing is good, but it doesn't remove weathering rinds.

Might be worth a try, though.

-the other Doug

Actually, Stu, I think the lightened area looks roughly the same in terms of the extent of duning as the rest of the surrounding terrain. It looks more to me like the lightened area has seen more deposition than the surrounding terrain -- the underlying lava-flow surface is more muted and softened in the lightened area.

I think what's happening here is that the prevailing winds are coming from the bottom of the image. As they pass over the hole, the air sinks a bit, and winds strike the rim of the hole along the top arc (all directions -- top, bottom, etc. -- relate to the orientation of your posted image). So the top arc of the rim is being eroded a little more rapidly than the rest of the rim, and the erosion product (basaltic dust, most likely) has been deposited on the ground beyond the top rim arc.

It's also at least somewhat possible that winds are entering the hole, swirling around, eroding the interior of the lava tube, and blowing dust out from the cavern and onto the ground above the top rim arc. I just don't think that Martian winds are powerful enough to reach into such a deep hole and scoop dust out of it, but I could be wrong. At any rate, it's impossible to model airflow into and out of that hole without having a decent idea of the size and shape of the empty lava tube, and we really have no way of determining that...

-the other Doug

Yes, it does! From this angle, it appears that there are clasts eroding out of the rock along its roughened edge. However, some of the Lump is also finely layered, so if it is a breccia, the entirety of the breccia is an inclusion in a larger piece of evaporite...

-the other Doug

Yeah, I noticed that, too. The appearance of the darkened area at the point of the rock is almost as if water was squeezed out of the rock and flowed out from the tip and onto the ground. Of course, that's not what happened, but it has that appearance. Instead, I next thought that perhaps the RATting of the rock pushed the left edge into the ground and levered the right edge and tip a bit off the ground, resulting in soil disturbances, but I see no other signs of soil disturbance anywhere else along the soil/rock interface.

My best guess about that dark patch is that the vibration of the RATting caused the soil to shift a bit, but if that's the case, I would have expected to see other patches of disturbed soil along the soil/rock interface.

I think that the berry movement is *probably* wind-related, but I suppose there is a very minute possibility that it was caused by RAT vibrations. However, if the latter were true, I would have expected to see more berries moving.

One intriguing possibility is that the single berry that had been sitting on top of the rock, at the RAT site, was energetically ejected from the RAT, flew through the air, impacted the berry that shows significant movement, rolling it down several centimeters. This explains the unusually large movement of that single berry, when none of the other berries have moved significantly -- you'd think that if wind *or* vibration caused that single berry to move, that others would have moved just as much. Hard to imagine a gust of wind that's powerful enough to move that one berry, but not powerful enough to move other, smaller berries elsewhere in the scene.

-the other Doug

I know I heard someone somewhere (most likely in the Opportunity subforum) say that the power is up to roughly 800+Wh, which would make our girl as clean as the day she landed.

-the other Doug

Actually, liquid water on Mars would behave consistently at nearly any atmospheric pressure we can imagine at which water can exist as a liquid. At least, at pretty much any point in a range from 10mb to 1b. The effect of winds would be different, but the speed at which water rises and falls is entirely defined by gravity. And since Mars is at roughly 1/3 G, water will fall roughly 1/3 more slowly.

I call as evidence Buzz Aldrin's description of the flow pattern of the wine he poured when he took Communion on the lunar surface. He said the wine poured in slow motion and moved about in the tiny chalice he used as it would on Earth, but more slowly and more with exaggerated motions. It was easier to make the liquid slosh and try to rise up over the lip of the cup than it would have been on Earth -- as he poured, the wine curled right up to the opposite lip of the cup. (Leave it to Aldrin to carefully examine the physics of fluid motion in 1/6 G while taking Communion... )

Roughly double the gravity (damping down the motions somewhat) and scale up a tiny chalice to rushing floodwaters and lakes, if not seas, and you get an idea of the semi-slow-motion, vertically exaggerated waves you'd likely have seen on Mars.

-the other Doug

Just a couple of comments, Jason:

First, why is the first Tn designation in quotes? I wouldn't see this as proper form, unless it was associated with an explanation of the designation system. (Yes, a very minor nit, I know.)

Second -- SCFs??? Methinks the acronym guys are getting a bit loopy. Instead of calling them Suspiciously Circular Features, why not just call them craters? A crater can be either an impact site or a caldera, after all...

BTW, must feel good to have your name out front of such people as McEwen and Porco. Good work, Jason!

-the other Doug

Let's see, a number of points, here...


No real problem here -- remember, the world is ending on December 21, 2012. So, of course it will be the exclamation point.



I'd think anyone who wanted to know when UMSF (or, more appropriately, its predecessor) began could simply look at the date on which Doug joined. Since he created it, I'd think he would have to have joined on the first day.

Also note that while Doug joined on 2/8/04, I joined on 2/9/04. A lot of us who showed up here at the beginning sort of knew each other from the sci.space Usenet newsgroups.


Actually, the biggest drought was between 1989 and 1997. The 1980s at least featured Voyager encounters with Saturn, Uranus and Neptune. Granted they were several years apart, but since they were the very first looks at the outer planets, they provided a huge number of bones to gnaw upon throughout the 80s. With the exception of the extremely small trickle from Galileo, there was really nothing between the Voyager 2 Neptune encounter and the arrival at Mars of MGS and MPF in 1997.

Those were very, very dry years. But, on the other hand, I didn't even have internet access until 1996 (as was the case for many), so there wasn't anything like what we've enjoyed with the MERs and beyond. The delivery system just didn't exist.


Interesting you chose that particular deity -- I long ago adopted that name as a portion of my spiritual name. I don't use it in public very often, of course, partially because most people are incapable of pronouncing it... *grin*...

-the other Doug

I truly love how, printed on the face of the CD (which contains my name as well, BTW):

"Astronauts: Take This With You!"



-the other Doug

Looks like a good landing site for MSL -- if it stood for the Mars Spelunking Laboratory...

-the other Doug

YES! I've been saying for a while that the entire Home Plate construct looks to me like remnants of a hot spring complex. Especially the way in which the layers within HP have been cemented and laid down -- it suggests (to me, anyway) deposition by mineral-rich water that has alternated back and forth from flowing to pooling.

I've known that several members of the Spirit team have favored the hot spring theory for some time. It's nice to see that they're hanging in there and finding evidence for their theory.

-the other Doug

I'm someone who sees the world in political terms -- I was just barely in school when John Kennedy was assassinated, I was in college when Nixon resigned, and the stuff that went down between those two events (including both the zenith of Apollo and the nadir of Vietnam) forever and indelibly shaped my perceptions. Political insights occur to me all the time, and it can be difficult to edit them out of my stream of consciousness as I comment on nearly anything.

That said, Doug and the admin staff have toed a very fine line with great aplomb and delicacy. Yes, there *are* some areas in which politics influence and even shape the course of UMSF, and a small subset (funding decisions, public outreach efforts and data sharing, to name a few) *are* within the bounds of this discussion. But, as Doug and others have said, there are many, many other places for that discourse to give vent to underlying political thought, theory and practice. And since such discourse tends to get, well, acrimonious and is not in keeping with the engineering and scientific discussions and speculations for which this site is known, it is completely fitting and proper for Doug and the admins to take whetever steps are required to keep it off of this site.

Remember, this is coming from someone who has to apply more self-editing than most to keep from pointing out the links I see between UMSF and politics... This has actually helped me in honing my skills as a writer and a curmudgeon. Those insights I actually do explore here go through an extensive review process in my own mind, to ensure that I'm commenting on basic processes of human societies (as they relate to grand and grandiose societal efforts such as the exploration of space) and not just the ideological differences between political systems or points of view.

I especially applaud Doug, in specific, for firmly insisitng that unmanned spaceflight can be celebrated and discussed without the need for constant comparison with the other side of the coin, manned spaceflight. There are fora out there that I simply cannot visit without raising my blood pressure to unhealthy levels, since they are founded primarily to advance agendas I find hateful... there are people right here at UMSF with whom I would probably get into violent arguments were such agendas allowed free reign, and I (and lots of others) would thus miss out on all of the wondrous things we *do* discuss.

I think one sign that Doug and the admins are doing the right things is the respect this site has earned amongst those who are actually planning, preparing and flying the missions. To see the same names here that we see in the author credits of articles in peer-reviewed journals, informally discussing their thoughts as they advance our understanding of the Cosmos, is a heady and invaluable experience. And hey -- when the PI of a major outer solar system probe refers to *us* specifically on a nationally televised documentary, showing pages of our own forum while speaking of the value of us, "the bloggers" (funny, I never thought of myself as a blogger prior to that), that is an especially sweet reward. (BTW, Doug, did Alan or the Discovery Channel people have to ask permission to televise images of the website, or is it in public domain?)

It's not about the snob appeal of hearing some scientist refer to this site as being at an exceptionally high level. It's not about using every rock in your path as a platform to push you own agendas. It's about having a safe, relatively friendly, forgiving but scientifically stringent band of brothers (and sisters!) with whom to share our thoughts and speculations. And I wouldn't trade that for all the tea in China. (Of course, speaking of China and tea prices... oops! Never mind! )

-the other Doug

Problem is, I don't think that the straight-line winds that actually cause cleaning events really get down into the bowl in which Spirit is currently sitting -- Home Plate lies generally in the topographic low of the Inner Basin, and straight-line winds are somewhat dissipated before they reach our current location.

If trying to engineer a cleaning event is ever a goal of the Spirit team, they'd probably try to analyze the prevailing winds and place Spirit at an angle into them, on top of the highest spot they can now reach with the bum wheel.

-the other Doug

We are at a somewhat similar juncture in our understanding of Martian geochemistry now as we were with lunar geochemistry after the Surveyor program. There are parallels, I think.

Without samples in hand, and with 1960s technology, the best we could do for in-situ examination of lunar surface rocks by unmanned landers was the Alpha Particle Backscatter device, a direct ancestor of the APXS units flown on Pathfinder and the MERs. With just the element distributions readable by those devices, we were able to infer the basaltic nature of the maria, but the anorthositic nature of the highlands was less well defined. It was one possible solution to the aluminum-rich distributions, but not the only one. It took until the fourth manned lunar landing for an actual chunk of anorthosite to be found and brought back to Earth, confirming the anorthositic nature of the Moon's original crust. (Small flakes of anorthosite had been found in the soils returned by earlier missions, but there was so little of it, even in the mostly basaltic breccias returned from Fra Mauro, that alternate theories for the Surveyor VII data weren't completely ruled out until the J missions returned significant percentages of anorthositic samples.)

We are lucky to have additional sensors on Mars -- the Mossbauer and mini-TES results are invaluable in identifying actual mineral signatures. But there are still more questions than answers when it comes to things like soil chemistry. The Viking biology results are poorly constrained at best -- hopefully the soils at the Phoenix landing site will be similar enough to the Viking soils that its results can better constrain the possible causes for the Viking results. But we're still in the same situation in re Martian soils as we were in those delicious months between the final Surveyor results and the first returned lunar samples; the peroxide theories mostly account for the observed results, but they're certainly not the only possible causes.

I'm hoping we can get enough information from Phoenix to be able to better constrain our ideas of Martian soil chemistry, because it's going to be a long time -- a lot longer than the 18 months between Surveyor VII and Apollo 11 -- before we can examine samples... *sigh*...

-the other Doug