Heck, we have seen an aspect of image processing even more basic than color balance in the Curiosity images, which took quite a while for everyone on the Curiosity team (MSSS and others) to resolve near the beginning of the surface mission.

As y'all may recall, the B&W images from the navigation and hazard cameras were, for the first several months of the surface mission, consistently flat, dark and low-contrast. Especially compared to images taken under similar lighting conditions from other landers, the navcams showed a consistently dark, low-contrast scene.

After a couple of months, the raw navcam images suddenly came through with more contrast stretch and more brightness stretch. We then saw a bit of an argument here on the forum, with many people (myself included) happy that the images were now more visually interesting and matched the overall scene brightness we were seeing in the mastcam imagery. Others were disappointed, since the darker images were purportedly more accurate in their depiction of the brightness of the scene.

So, while showing a dark, washed-out scene may be a little more "true" to what the eye might see in situ, it actually hinders both the eye's ability to pull out fine detail and also makes for a less aesthetically pleasing image.

As someone with a B.S. degree in photojournalism, I can tell you that the principle aim of photography is not always to perfectly and accurately represent what the eye could have seen in the scene at the moment the photographer pressed the trigger. Photographs also serve to highlight specific elements of the scene, and manipulation of gray scales (even using old-fashioned darkroom techniques) serves to bring out detail not immediately obvious to the eye, as well as to improve the image artistically.

As good and professional as our friends at MSSS are, I believe (and Mike can likely confirm) that they are primarily imaging technicians, not primarily artists. Individual images are not planned for the artistic balance of picture elements or the most dramatic lighting and gray-scale effects, and that's likely how it should be. We here in this forum are the people with (pardon the expression) the time on our hands to interpret the engineering images in an artistic fashion. And, as with any expression of art, what is "good" and what is "bad" tends to lie as much in the eye of the beholder as in the intentions of the artist.

Just my two cents' worth...

-the other Doug

As something of a non-sequitur, the Science channel runs a program called Futurescape, with James Woods as narrator. The advertising tag line for this show is "What happens in the future starts right now." However, my mind keeps wanting to merge this into a different ad line from a different ad campaign, and thus making it a cosmologically more-correct statement:

"What happens in the future, stays in the future!""



-the other Doug

Bungle Bungle looks a lot like Hottah, don't you think? Exactly like a coarse-pebble concrete.

I think they did do ChemCam characterization of the cementing unit at Hottah -- it would be interesting and instructional to see if the Bungle Bungle unit's cementing unit is chemically similar.

-the other Doug

It is fairly common to run across the imagery in the press of Venusian landers being "crushed" to death within hours of landing. IIRC, what happened more is that the systems which maintained the internal Earth-normal pressurized spaces (which housed the electronics) failed and the internal pressures and temperatures rapidly equalized with the local environment. (Russian electronics in their space probes of the day were generally air-cooled and were maintained at sea-level pressure, often in plain air but sometimes in a nitrogen-only atmosphere.)

The pressure shells didn't dramatically implode (once they figured out about the surface pressure, as was noted below), but the effect was quite similar. And I believe that the ultimate failure of the pressure control systems often occurred due to implosion of connecting pipes and of windows in the sea-level-pressurized spaces used to look out onto the surface and connect to external systems.

-the other Doug

Don't worry, Phil. We'll just cross those ridges when we come to them...

-the other Doug

Yeah, this stuff looks to be almost all plagioclase laths, with very little actual basalt forming the matrix. That's what fooled me initially into thinking it was some kind of clastic rock.

I gotta say, though, while I have seen a lot of basalt with plag laths in them, I'm more used to seeing fine, feathery laths inside moderately vesicular gabbros. I know some basalts have such a high plagioclase admixture that you get this mass of tabular crystal laths (as we're seeing here), but doesn't that usually form at the top of a basaltic melt? The plag, being highly aluminous and less dense, would tend to float to the top of the melt, wouldn't it?

Wonder what that says about seeing such formations at Gale...?

-the other Doug

Gee, I thought the "fire ring" on the other side of Dingo Gap was a classic large-sized version of the "bubble formation." I believe we saw some bubbles as large, or nearly as large, as that fire ring back when we first encountered them on the way to Yellowknife.

And I know I have yet to run across anything published on the bubbles. I'd love to hear what the professionals are theorizin'...

-the other Doug

I believe the Chinese deserve many kudos for achieving what they have managed to achieve on this flight. Historically, a given country's first attempt at a specific type of mission is not completely successful. Just in terms of lunar probes, the first Soviet and American missions failed (either partially or completely) on the order of four times out of five.

Granted, the Chinese are somewhat standing on the shoulders of giants, the state-of-the-art being so much more advanced now in so many of the fields (electronics, communication, propulsion, etc.) that must come together for a mission like this to succeed. But that has historically been true for every other "first" attempt at a given mission. The very first people to try something are always stepping into the unknown.

However, I am positive the Chinese will learn from Chang'e 3's failures as well as its successes, and we are likely to see a more robust unmanned lunar exploration program as a result.

Even if we don't get any more beautiful images from Yutu, I'm impressed with the capability displayed. And I'm already looking forward to seeing what Chang'e 4 will accomplish.

-the other Doug

Well, obviously we need to add a new device to the next rover -- an I-SPTD (In-Situ Page Turning Device), so that we can open and read all future Martian books found lying half-buried in the soil...



-the other Doug

p.s. -- if I read my old High Upper Martian correctly, the remains of the cover bears an emblem that translates to "How I Did It, by John Carter"...

Ah, yes -- every forum "owned" by Doug and by Alex Blackwell, the guy who e-mailed me about this place starting up. I was already a member at this point, member number 15, joined on 2/9/04. So, I have been here, in and out of lurker mode, for the entire 10 years.

It has added much to my life. Thanks for taking the leap of faith and setting this up for all of us, Doug!

-the other Doug

There are a number of different configurations you could use for a rake-like implement off of a rover, though. A large flap-like rake would serve to disinter buried rocks and pebbles, at the cost of possibly getting hung up and also of piling up large mounds of dirt. However, a dixie-cup-sized device, open at one end and with a mesh at the other, could be used to collect cobble-sized samples which are shallow-buried for a sample return mission.

For in-situ analysis, you would need to identify a need to disinter buried cobbles as part of your sampling methodology for this kind of device to become important. For example, if you come up with a theory that only buried rocks will display a given desired-to-observe chemistry, you might want to develop a way of disinterring such rocks for easy transport to your sensors.

I get the gut feeling that such a sampling methodology would be more useful for sample caching in preparation for a sample return mission than for in-situ analysis. But in either case, I'd think you would need a compelling reason for wanting access to shallow-buried rocks before getting into the complexities of designing such a raking mechanism.

-the other Doug

Also, remember that when the human eye sees a vista that is predominantly in shades of red, anything in that image that's actually gray tends to look greenish. It seems to be a function of human color perception. Not saying that there aren't some green-tinted layers, here. Just saying that my eye has been fooled into seeing greens in MER and MSL images where the material in question was actually quite gray.

-the other Doug

Is there a way to send a mass PM to all members? It's a little like using thermonuclear devices to solve a mosquito infestation, but it would make sure everyone is aware of the survey...

-the other Doug

Speaking of behaviors of processes over astronomical timeframes always runs the risk of ignoring the nature of relatively short-term phenomenah which occur in bursts and blurps. (For example, the overall process of accretion over a 4.6-billion-year period resulted in the Earth-Moon system, but the day of the Big Whack created, in mere hours, the conditions resulting in the current system, its angular momentum, Earth's rotational period, etc.)

If non-homogeneous concentrations of volatiles exist within Ceres' outer crust, maybe water ice spurts and sublimates for a few thousand years and then stops, then later methane ices do the same thing over a few thousand years, etc. Each episode of volatile transport would have its own effect on the surface coatings at the poles and in other cold traps, depending on the specific volatiles being transported and how they react to sunlight and radiation over time, etc.

Ceres being so much closer to the Sun than the Jovian and Saturnian moons, it's hard to make direct comparisons, but it's possible that Ceres has (or had) a wider range of volatiles than the moons we've observed, and definitely sees a higher solar constant than do the outer planet moons. These would seem to be important factors, too.

As you say, though, much will become more clear as we approach Ceres with Dawn and get some of the hard data that will let us answer some of these questions.

-the other Doug

The funny thing is, the algebraic equation 14mi/22km results in a factor of one. But as to unit of measure, that factor is indeterminate. Either side of the equation can be rendered into the same uom as the other -- i.e., 14mi/14mi, or 22km/22km. Since it cannot be a radius of both 1km and 1mi, the resulting factor of 1 is thus indeterminate...



-the other Doug

Yeah, I hear you. When I was a boy, we had to walk to the Moon. Uphill. Both ways.



-the other Doug

That looks like a conglomerate rock, but instead of being a matrix with rounded streambed-like inclusions (as we saw at Hottah) it looks like a lot of sharper fragments, arranged willy-nilly like a "dog's breakfast" and with far more inclusions than matrix. I'd even be thinking breccia, but the clasts are a lot sharper and flatter than I would normally expect to see in a breccia.

The individual shards of rock appear to be layered as well -- very fine layers, when you look at the scale of the image.

Oh, little rock, what stories do you have to tell?

-the other Doug

Okay. Well, hey, it was a thought. Might still be interesting to compare the testbed wheels to Curiosity's, if just see if the wear and tear on this wheel design is inherent in the design and will occur pretty much irrespective of the surface conditions, or whether a surface with a larger admixture of sharp-edged stones will (as common sense would suggest) cause more rips and tears.

Again, I have no doubt that the wheels will work fine even if large sections of the thin aluminum end up getting ripped and torn. As with many of us, I'm sure, I just find this an interesting engineering exercise. (The absolute worst image I have is of Curiosity sort of humping up and down if a large piece of metal ends up sticking out of one of the wheels, a dynamic I find unlikely considering that even if a piece were to catch on a rock and rip radially outwards, the wheel motion would then tend to push it harmlessly back in towards the wheel hub.)

-the other Doug

Would manganese deposited hydrothermally be suspended in water in the form of a manganese salt? Or are there more complex chemical interactions which would keep manganese in suspension and then initiate its precipitation out of solution? And would this imply warm, or even hot water (i.e., would manganese come out of solution as the water cooled)?

-the other Doug

As has been pointed out, the MSL mobility testbed unit displays similar rips and tears in the wheels. It might be instructive to see the current status of the testbed wheels, along with a rough history of the number of meters it was driven and over what surfaces. I recall seeing video of the testbed recorded well before Curiosity landed that shows significant ripping and tearing in its wheels, so it must not take a huge amount of driving for these things to appear.

For the testbed experience to be truly applicable to the asset on Mars, I imagine the weight of the testbed would have to be roughly one-third of the actual MSL. I recall that the MER mobility testbed was weighted in this manner, I'm assuming MSL's was, too.

-the other Doug

The pattern of the light-toned mineralization looks like it followed a set of cracks in the rock. Suggests aqueous intrusion to me.

What also catches my eye in this picture are the extremely fine lineations on some of the darker rounded rubble at the bottom of the image. Many of the tiny pebbles have very fine-grained scallops along the edges, others have hair-like, perfectly parallel grooves, some display aligned pits along their rounded surfaces. I'm guessing these are the remains of extremely thin strata, I guess I would find it harder to believe they're carved by eon-long persistent sand particle saltation.

-the other Doug

So, observed species abundances reflect the end result of a process of emission of some carbon species, the dissociation of those species in the radiation environment, and finally the recombination of some species (as allowed by the environment) and the emplacement of these recombined species on the surface?

Just trying to wrap my mind around the most likely process. Seems to me that modern science offers a lot of theoretical concepts that are weak on the actual processes you have to have to get to the current observed conditions, which is why I'm always harping on the process side of things.

-the other Doug

I guess I'll be the one who asks -- how much more or less susceptible to degeneration by the radiation environment are carbon-carbon and carbon-nitrogen bonds when compared to carbon-oxygen bonds?

In other words, since the environment rapidly dissociates a lot of molecular bonds, can the lack of more interesting carbon bonds than C-O be attributable to it?

-the other Doug

A holiday is one of those days when you don't have to do drab, uninteresting things and can instead do things you really want to be doing...

Come to think of it, if I did what you do, I'd wonder what a holiday is, too...

-the other Doug

And, of course, you can always respond to Bill Nye, who is sending out requests to everyone who gave money during our fund drive to give more money...

-the other Doug