The turret is brought to bear!





-the other Doug

MAHLI is an amazing instrument. Color carries so much information, so having as good or better resolution from MAHLI as we got from the MER MI and the color information to boot is really, really satisfying.

Now, a lot of people seem to have made up their minds that this is a chunk of basalt, but MAHLI shows very tiny vesicles in the rock matrix, much smaller than the large holes which look less like vesicles and more like places where clasts have dropped out of the rock. It's somewhat unusual to have two widely diverse vesicle sizes in a single chunk of lava -- do we have ChemCam information that definitely shows this rock as a chunk of basalt? Not just basaltic (since the base material of the matrix could well be basaltic, even if it's cemented sedimentary rock or even impact melt), but actual, unaltered pyroxene or olivine?

I'm looking forward to hearing about the composition of Jake. Should provide some good insights.

-the other Doug

Just turned on an episode of "Mysteries at the Museum" on the Travel Channel. They visited a museum in New Mexico that has a well-designed, full-sized MER model, which encouraged them to tell the tale of Spirit, The Mars Rover!

Gee -- did you know that just as soon as the Sol 18 anomaly was resolved Spirit had to immediately run for the southernmost place it could get to so it could survive the winter that was closing in fast (and that promised a full 90 days of darkness)? And that, during this frantic flight for survival, her wheel then failed and then they discovered silica in the failed wheel trench and so stopped worrying about the winter?

Not exactly how I remember the timeline back in 2004...

-the other Doug

You know what? I'd bet you any money that for much of its existence on the surface, the right side (from our current position) of Jake was buried. The left side has been exposed for far, far longer. Notice how the far right edge bulges out, has not been "planed" down to a smooth edge as the left side has. And there is an entirely different (and more representative of the type) erosion rind on the left side than the jagged, "melting" appearance we see on the right side.

-the other Doug

So... the melty-looking layers have rounded protuberances, but not spheroid. Well, as I said, we'd know more once we got some better-resolution images of Jake. And now we do.

Boy -- those layers are interesting. They can't have formed in the orientation that Jake is currently sitting, and yet the ragged edges of the layers almost appear to have flowed down the side of the rock. Has to be some trick of aeolian erosion. But this is obviously not a dense piece of lava, like the standard ventifacts we see elsewhere in the area and on Mars in general. As has been pointed out, they erode to smooth surfaces. And this thing has sat there long enough to erode down to a pyramid shape, so it has to have something to do with the actual physical strength of the rock faces and the differential strength of the different layers.

-the other Doug

Yes. Very, very obvious. Whether it's a clast in the lighter-toned unit or just a different kind of rock that was once deposited on the lighter-toned unit when that unit was the surface layer, it's hard to say.

-the other Doug

Oh, agreed. I was only put in mind of spherical inclusions because of two of the features I circled in particular -- in the row of three of my marking circles along the right side of the rock, the second down shows what looks like an empty socket, and the feature below it reflects light into a nice little subsolar point that suggests a spherical surface to me.

Obviously, we will have closer images in the next few Sols. I'm really looking forward to seeing what MAHLI can do on a close inspection, here.

-the other Doug

Hmmmmm... is it just my imagination, or does ol' Jake here have spherules embedded in it? See the circled features below.



-the other Doug

There are a tremendous number of pyramid-shaped rocks on Mars. They are classed under the general name ventifacts. The pyramidal sides are caused by eons of wind erosion. This creates a number of shapes, including the pyramidal.

Look through the images from the MERs -- you'll see quite a few examples. Heck, there are several ventifacts in view at both Viking landing sites and at the Pathfinder site.

-the other Doug

I know I have been assuming standard map orientation with North up, West to the left, etc., etc. Assuming the HiRISE image was taken in the afternoon, that would be consistent with the lighting.

Obviously, if we need to slew a map around for ease of demonstrating a particular route (as I can imagine may be needful when we get around to things like driving up a drywash cut canyonlike into the lower mound), it would be nice to see a compass rose somewhere, just for general orientation... and to help people like me find things when someone says "it's just west of the Sol 24 position."

-the other Doug

Thanks! It can be a little difficult recognizing these flat-to-the-ground features from above, can't it?

-the other Doug

Okay. In that case, I'm finding it really difficult finding the feature in the surface image in the overhead context. And, correct me if I'm wrong, but while the feature I marked in the overhead was more north of us at the Sol 40 position, is it not west-northwest of us now?

I suppose the mastcam mosaic in question was taken well before either of those two stops, though. Ah, well. The surface feature still looks interestingly like some kind of cemented underfloor.

-the other Doug

I'm assuming that the marked areas in the next two images, from above and from the surface, are the same feature?





From above, this feature looks, at first glance, to have a crater morphology (until you look closely and see that its edges are in positive, rather than negative, relief). From the ground, it kind of resembles a miniature version of Home Plate.

As Stu said -- fascinating geology. Almost looks like a sedimentary process laid down a fill inside a small crater which has been more resistant to erosion than the surface in which the crater was originally formed.

-the other Doug

As one of the first people to mention that the navcams looked tremendously murky without a lot of processing, I have to say I like the new stretch. Previously, as mhoward has noted, the histograms on the navcam images were all piled up in the dark half the available dynamic range.

As someone who wants to just look at the images and doesn't have an automated pipeline from the website into Photoshop, I'd rather be able to look at and enjoy the images directly, rather than feeling the need to save them and run them through contrast and brightness gamma enhancements just to have a reasonably non-murky image in which my old, tired eyes can actually pick out good details.

That could be just my own reaction, though. As always, YMMV.

-the other Doug

Yes, the spiral patterns resemble, more than anything else, the pattern of modification one sees at Mars' poles. But... Vesta couldn't possibly have ever had enough atmosphere to support ice caps, could it?

-the other Doug

So far, from what I've heard, ChemCam is seeing mostly basaltic rock here, too. A vast majority of the surface of Mars is basaltic rock, I think -- heck, even the evaporites at Meridiani seem to be basaltic fine-grained sand particles cemented primarily by sulfur salts.

The problem with Martian surface geology is that, in many locations, the rocks have been transported to where they lie on the surface from elsewhere. Even laid-down beds of rock strata (like the various layers identified on the floor of Gale) were likely made up of fines and rocks transported in from elsewhere and then laid down in beds by depositional or sedimentary processes. I mean, c'mon -- what makes up an alluvial fan? The fines and pebbles that were washed into the location by moving water. Yes, they were emplaced alluvially, and may have been modified in the process of deposition, but ultimately the rocks and fines were originally erupted onto the surface, or laid down sedimentarily, somewhere else on Mars and have been transported to where they lie now.

-the other Doug

Actually, this feels a lot like when Spirit arrived at the Columbia Hills and immediately found Pot of Gold rock. And Squyres said it was like starting the mission up fresh.

This feels like we're starting a new exploration all over again, here...

-the other Doug

It appears they are not hematitic...

-the other Doug

Hmmm... there are now several Mastcam images at the raw image site, taken on Sol 36 between 06:30:17 and 06:35:19 UTC, that show a pretty blank scene. The first 10 images are grayscale, the next 10 images are all blue-filtered, and the final 10 images look to be the natural color of the sky.

Could they have possibly targeted the Sun for the Phobos transit and the pointing was slightly off? Timing doesn't seem right, though.

-the other Doug

The actual heat shield impact is visible in the MARDI film, near the bottom of the frame about one to two seconds before backshell release. It's a suddenly-appearing dark dot that obviously shows a small circular plume of ejecta puffing out around it.

-the other Doug

It does sort of look like a form of mudstone, doesn't it?

Actually, of course, it's just the remnants of the concrete floor of the old thoat pen that used to stand here...

-the other Doug

If you look closely at the bellypan, underneath and offset from each of the hazcam lenses there is a spring. We know that the hazcam lens covers were designed for a one-time deployment; the springs were supposed to move them completely out of the way of the lenses, for good. My guess is that the lens covers are out of sight on the bottom of the lens housing, one each attached to each spring visible in the MAHLI images.

-the other Doug

Looks like a breccia, a tuff with inclusions or even a conglomerate rock is being eroded away, here. At least, the part that sticks out above the surface is being eroded. In some areas the matrix and the clasts look to be the same hardness, and in others it appears that the matrix is softer and is eroding faster than the clasts, letting the clasts drop out as cobbles around the base of the rock.

Also looks like most of the clasts or inclusions are roughly spherical...

-the other Doug

Gee, it appears that Jupiter is still in the process of clearing its neighborhood of other solar-orbital objects. Per the new definitions, it looks like it doesn't qualify as a planet.

-the other Doug

Egads! I mean, I know there is a movement out there to try and put down anyone with intelligence and an education (for reasons forum rules won't let me get into), but to let these kinds of comments about people smart enough to land spacecraft on other planets into media reporting on the space program is just plain wrong.

Can you imagine if CBS News, in 1969, felt it had to "counter-balance" Walter Cronkite's enthusiastic reporting on the space program with Ricky Redneck's comments on how we shouldn't let these gul-durned eggheads control everything?

I never thought the future would really bring us into the age of the Marching Morons. I'm disappointed to see I was wrong. Which does bring up the concept of using the space program to directly attack the problem -- you know, let everyone know about all those wonderful colonization opportunities on Venus, for example...

-the other Doug