I said at first glance...

However, isn't pumice a rather weak, friable rock? This set of rocks doesn't look to be as wind-eroded as the vast majority of the rocks nearby. If it's pumice, wouldn't you think it had been emplaced here pretty recently, geologically speaking?

I'd love to examine it a little more closely, but I bet they don't want to get bogged down bringing Curiosity's tools to bear on every somewhat interesting-looking rock we come across. Especially this early in the campaign. We'll be seeing a *ton* of interesting rocks.

It's just so hard to be patient...

-the other Doug

At first glance, the rocks in the image NickF posted look like vesicular gabbro with large vesicles, but I suppose they could be breccias in which softer clasts have eroded out, leaving the matrix with vesicle-like holes.

Interestingly, all of the other rocks in the image are heavily wind-eroded ventifacts, while the little pile of vesicular rocks are not nearly so obviously wind eroded. Maybe they haven't been in place for nearly as long?

-the other Doug

I'm on tenterhooks waiting for some imagery and APXS work that would indicate whether or not these spherules are deformed hematitic concretions or some form of lapilli. If lapilli, the big question would be whether they were formed by volcanic or impact processes. There is plenty of evidence on Mars for both processes.

Of course, this rock bed could have been formed by a combination of the two processes -- volcanic lapilli could have been spread around the fringes of the impact target sites for any one of the very large craters in the area, and been caught up in a moving tide of impact melt to become clasts in a melt matrix. The same thing could have happened with concretions being embedded in impact melt, and impact-generated lapilli could always have been caught up in a pyroclastic flow of some kind that left them embedded in tuff.

Isn't it fun how impacts are both a blessing and a curse? A single impact into an intact pile of rock beds shows you wonderful evidence of the emplacement and composition of the beds over time, and exhumes rocks from deep within the strata. On the other hand, throw impact after impact onto a set of rock beds (as happened during the LHB) and you get a ground-up, brecciated set of jumbled strata, greatly enriched by impact melt (which can have profoundly altered composition from the target rocks). And with each large impact you're creating new impact melt that is an amalgam of the elements not just in the surviving rock beds but also in the impact melt already emplaced by prior impacts, and in ejecta from other impacts that could have been transported there from hundreds of kilometers away (and exhumed from very different depths of strata). It seems to me it would be almost impossible to straighten the whole mess out into its original emplacement and compositional stratigraphy.

-the other Doug

I thought they were calling the whole area Fin Ridge or something like that... though I guess they need some kind of separate name for just the outcrop within the ridge.

BTW, Gracie Allen Formation? I *like* it!

-the other Doug

Considering that Sojourner's APXS identified some of the rocks it examined in Ares Vallis as andesitic, I can understand how someone might look at a basaltic rock on Mars like the one we've been discussing, with such large crystals, and make a preliminary identification of andesite.

-the other Doug

I believe we established quite a while ago that hematite concretions like the blueberries are resistant to melting. This looks like breccia with partially broken-up concretions as the clasts within the breccia. The matrix appears quite uniform.

My best guess is that there were concretions in the soil when the Endeavour impact occurred, and what we see here is impact melt that gathered up the unmelted concretions in the debris cloud as it cooled, making it impact melt breccia with concretion clasts.

In other words, it's blueberry muffin rock.

-the other Doug

My biggest issue with anaglyphs is that the red-blue glasses you can find out there are very cheaply made, with fragile and easily scratched cellophane lenses. While still basically usable, my glasses leave me looking, at times, at a red-blue blur.

I think I'd like anaglyphs a lot more if there was a really easy way to get the cheap glasses in bulk (just discard when they get all scratched up), or to get a sturdier, more scratch-resistant pair.

-the other Doug

I'm not yet convinced that the blueberries are embedded into the rocks of this outcrop. They could just be scattered on top of these rocks, either as a lag deposit from previously overlying layers of concretion-bearing rocks that have since been eroded away, or lifted there by aeons of impacts that have redistributed such melt-resistant fragments liberally throughout the area.

A good MI campaign ought to shed more light on whether or not these outcrops have embedded concretions, or just have concretions draped over them.

-the other Doug

Even though I have my pair of red-blue glasses sitting within inches of my monitor, I actually prefer the cross-eyed technique, especially for color images. Flicker-gifs are good for scenes with relatively shallow overall depth of field, like a close-up of a rock on the ground, but not so good in my experience for deep images, like those that run from foreground to horizon.

I'm thinking people have enough differing tastes in how they like to view 3D images that, at least with current technology, we ought not be looking for one best technique, but instead ought to try to use a variety of techniques so as to give everyone a shot at being able to view these images using their own favorite technique.

-the other Doug

I showed the latest image of this outcrop to my roommate, who pointed out its resemblance to a large pile of, er, thoat droppings.

My hope is that this is the edge of an upturned flap of rock strata that was violently flipped during the impact that formed Endeavour. It looks like the edge of a strata that dips in towards the center of Endeavour, though that's hard to tell with any certainty from this angle.

Anyone think this resembles the Woolly Patch that Spirit studied, which is suspected to have been a small clay outcrop?

-the other Doug

Just have a curiosity (small C) -- if we do get to some phyllosilicates, what does Oppy have left to bring to bear for examination?

I imagine we can at least brush the rock surface and the APXS should still give us some good data. And we can take some MI images. But is the Mossbauer capable of getting good spectra anymore? And if not, how much info can we get with what we got left?

Again, just curious.

-the other Doug

I also think it's worth mentioning that Mariner 2, also named Mariner-R, was the first successful flight of the Ranger spacecraft bus. It's a tribute to the overall design that it survived (barely) to a Venus encounter, something it was not exactly designed to do.

-the other Doug

Nice catch on whitecap, fredk. Though I'm only prepared to fully agree with the left side, the front and right may not be as differentially eroded. But, yeah -- the white rock looks to be a little on the softer side of the Mohs scale.

I'm really impressed with that contact, though. It really appears that there is a very dark band of rock sandwiched between the very white rock and the gray, apparently basaltic rock that forms the base of this particular ventifact.

Now, this would seem to me to be a really excellent target for ChemCam -- the ability to analyze each of the three strata in a rock like this seems like exactly the kind of thing ChemCam was designed for.

-the other Doug

"Whitecap" definitely shows a contact in the rock. I think this makes it very clear that the light-toned chips we've been seeing in the pavement aren't just reflected light off of shiny surfaces. There is a very nearly white rock mixed into this pavement, and whitecap shows that the light-toned rock is nearly as hard as the gray, apparently basaltic rocks. Note that it has been wind-eroded to the same degree as the very dark band across the contact and the lighter gray unit that forms the base of the rock. No little shelves that would indicate different degrees of erosion, and therefore hardness, for each rock type.

-the other Doug

This is one of the reasons I'm so excited about getting some actual heat flow information from Mars, so we can begin to intelligently model Mars' thermal history.

-the other Doug

Now, *my* best understanding of the rift systems on Mars is that they were created as the weight of the Tharsis Bulge distorted and cracked the underlying crust. No mantle convection or crustal plate processes are required for a rift system to form, just enough weight on the crust to make it crack apart around the heavy weight that's distorting the crust in the first place.

What I have always found interesting is that it appears only the crust to the south and east of Tharsis cracked under the weight. The crust to the north of the bulge doesn't seem to show the same kind of crustal cracking that formed the rift systems.

-the other Doug

It's amazing to me how we tend to hold our heroes close to us, thinking of them as personal friends, even though we have never met.

For example... I work primarily in customer service for a large cable TV company, troubleshooting issues with IP services such as internet connectivity and voice-over-internet phone (VOIP) services. Yesterday, after I heard the news of Armstrong's passing, while making conversation with one of my customers I said it was a sad day for me, as we had just lost the first man to walk on the Moon. My customer responded, concern in his voice, with "Oh, Neil died? Oh, no."

These are the things that hold us together, as societies, cultures and even as an entire race.

Let us all wink at the Moon in remembrance, and in solidarity, to celebrate a great human achievement and the man at the tip of the spear who took those first steps for all of us.

-the other Doug

I believe the geologic term for this is sorting. The surficial material here at Bradbury Landing is well-sorted, meaning there is not a random distribution of particle sizes from fines to boulders. As John Grotzinger pointed out in an early press conference, this suggests the surface is a lag deposit, where a deflationary process has preferentially removed all of the particles of the sizes that are most easily transported by the given process, leaving a lag deposit of the particles that were harder to move and, literally, left behind. As an opposite example, the lunar regolith is considered to be poorly sorted, with impact processes being the only deflationary processes in place, and impacts tend to transport particles of all sizes non-preferentially.

One good reason why the surface is reminiscent of the blueberry paving in Meridiani is that, per the best theories I've heard, the Meridiani surficial material is also a lag deposit. The very soft, friable rock that once covered Meridiani has all been deflated by aeolian processes, leaving the much more massive blueberries (which aren't nearly as easily transported by wind) in place as a lag deposit.

The deflationary processes do tend to round the edges off the lag particles, resulting in the more rounded appearance.

On Earth, a similar process would be the one that paves a creek bed with well-sorted, rounded pebbles. The transport mechanism (water) may be different from the primarily aeolian processes that have held sway on Mars for giga-years, but the principle is basically the same.

-the other Doug

I was just preparing the exact same post, Emily. Tectonics are evident on every body we've looked at closely in the inner solar system. You can find such fault movements (I want to call it a strike/slip fault, but I'm not certain enough of my terminology to say that definitively), as shown in the Ius Chasma image above, on the Moon and Mercury fairly easily, if you know what to look for. I believe there are similar features on Venus, as well. And wrinkle ridges are quite common everywhere that the weight of enormous lava flows has put pressure on the underlying crust.

But the only place we've seen actual evidence of plate tectonics is here on Earth. At least, thus far.

-the other Doug

I recall reading that Mars' atmospheric humidity often reaches 100%, but that since the air is so much thinner and colder than Earth's, it can hold only a very small amount of water vapor, so that a very slight increase in the actual amount of water vapor in the air raises the percentage by a very large percentage.

So, it's relatively easy to saturate Mars' atmosphere in a given location with an overall very small amount of water vapor. A reading of less than 10% would, I would think, indicate an extremely dry air mass.

-the other Doug

Fred -- if someone showed me your b&w image in almost any other context and asked me where the picture was taken, I'd probably say somewhere in the canyon regions of the American Southwest.

I'm with Nick -- absolutely blown away.

This is gonna be *fun*, guys....

-the other Doug

The Moon was in the same phase as 43 years ago on 7/20 about three days ago, so yeah, she's really close to the same.

-the other Doug

Godspeed, Neil Alden Armstrong.

-the other Doug

I'll usually say either Curiosity or MSL, but when typing I have on occasion abbreviated the name to Curi. Pronounced the same as Curie, but without that possible mix-up with the backup Pathfinder rover's name.

-the other Doug

Remember too, if you start saying "Hey, with a bigger booster we can add..." and go down that road, then you're getting into unproven EDL realms, you have to re-do your parachute, your landing strategies, etc., etc.

And then your proven, lowest-risk bid of "We already know the Phoenix architecture works, so we'll just duplicate it" becomes something entirely different.

I hear they are still building Delta II's...

-the other Doug