Rovers on Mars

whats the point of the radiolarians and forams and oolites?

Just other things that have a similar shape. I'm not suggesting that's what's up there or anything.

i guessed not. That would be too much to hope for. are there new batches of pics coming in ? Is there a homepage satt?

An update from JPL, color this time.

This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured on the 10th day, or sol, of the rover's mission by its microscopic imager, located on the instrument deployment device, or "arm." Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or "seed."

The examined patch of soil is 3 centimeters (1.2 inches) across. The circular grain in the lower left corner is approximately 3 millimeters (.12 inches) across, or about the size of a sunflower seed.

This stretched color composite was obtained by merging images acquired with the orange-tinted dust cover in both its open and closed positions. The varying hints of orange suggest differences in mineral composition. The blue tint at the lower right corner is a tag used by scientists to indicate that the dust cover is closed.

The home page is here: http://origin.mars5.jpl.nasa.gov/home/index.html

And here's one for you Farmerman, a nice mineral map:

This map of a portion of the small crater currently encircling the Mars Exploration Rover Opportunity shows where crystalline hematite resides. Red and orange patches indicate high levels of the iron-bearing mineral, while blue and green denote low levels. The northeastern rock outcropping lining the rim of the crater does not appear to contain much hematite. Also lacking hematite are the rover's airbag bounce marks. This image consists of data from Opportunity's miniature thermal emission spectrometer superimposed on an image taken by the rover's panoramic camera.

I almost posted thhe color shot of the little chunks. Almost like lava ropes and concretions.
The shot showing the tes hematite hits may have to be shot a few times, perhaps the bag bounce sites are an artifact of dust being kicked up and if they train the camera to that site periodically maybe we can see some erosional processes in action as the color gets modified by wind blown material

The web site linked above has hi-res images of the microphoto. There are at least a couple of speherical objects, each with a pock mark on it. There are also shards with circular holes in them.

I'm betting that the spheoids are microtektites with gas bubble formation on them (like the ones in the B&W earth image above). I think the shards with the circular holes are also impact related. I'm guessing that the molten material from impacts contain gas which form bubbles in the material when it solidifies. Then over the eons, these shards have been broken due to relentless of wind storm weathering.

That's my guess.... for what it's worth (and it probably ain't worth much)

look up the bibliog for a friend of mine billy Glass, hes a tektite specialist. I think he just retired from U Del. and USGS. Hes probably got as much tetkite material pub'd from earth strewn fields and I recall seeing a photo record of typology of tektites. Its interesting but an area way out of my field, (except for the geochem makeup when these things fuse)
Im still intrigued why the tes has made such quick color differentiation between the thump marks and the area showing hematite signatures

There often appears a similar structure in natural things, e.g., galaxy-hurricane-ammonite.

I'll try a guess. Maybe the surface color differences are due to reflectivity of the material in a compressed/matted condition. Kind of like when you brush your hand on velvet, you get a reflectivity change which makes the material appear to be a different color.

In this case, the small particles of sand may have cohesive properties due to their shape which causes them to "mat down" when compressed. Given the wind storms which have been seen on Mars, and the age of the surface we're dealing with, almost all of the loose material in this crater is probably wind blown from somewhere else.

It makes me wonder just how they expect to find Hematite in this area unless they plan to dig for it. What form do they expect the Hematite to be in? Sand form, or solid chunks which won't blow around?

Another possibility on why the Hematite is missing in the rover airbag bounce marks (see color mineral map above) might be that it's stuck to the airbags.

Another is that there might have been a chemical reaction induced by the compression of the material due to the airbags...

Why is the image generally more red in the distance, and more green in the crater (near the lander)? Has the crater been collecting wind blown sand which has covered up the hematite in the crater, or was the hematite blown out of the crater when it was formed?

We need more data. There are too many possibilities here.

Isnt it great when you make a list of all the possibilities and look at them in a discovery mode?

If the reflectivity of the "crushed velvet' color is real, then they have a spectrum in the little on board computer that can plot this. For example, an oxide may show up with three or more diff reflectivites and we may be looking at orientation as you said "crushed velvet" thats a good possibility. I was always a fan of putting an xray flourescence unit or a diffractometer but because these use so damn much energy theyd need the suitcase batteries.

we could be looking at olivine dust which, because it has iron, it would oxidize in some time, but the lander had kicked up a pile that covered the surface with its own minerals. thats why id like to see many shots of this area over a few days to see if any stuff migrates by wind, and maybe the chemistry will be reflective of that.

Recent Image from the Nav Cam:



These look like sedimentary formations which have been blasted open by impact, forming a portion of the crater wall.

or igneous rocks with layering of more resistant minerals as the magma cooled. The layering could be wind scouring like we see in the sphinx. It does have a sed look at places, but not in others. You can see that dust accumulates to the right side of certain rocks.

I agree the crater wall has been been lifted into a raised rim. POAG (1990 in his book about deep Craters on earth , developed an anatomy of typical crater side walls. They have 2 features
1 a raised rim on the outside of the crater and

2 Immediately inside of this is a series of slump blocks that are just chunks of what didnt get ejected

cool. Good photo too.

Yup, layered wind weathering like Sphinx, good point.



Yes, I'm familiar with this "anatomy of a crater". It was referenced on a PBS show which discussed Meteor Crater in Arizona. I think their Web Site also discusses it.

We need more data again.

What do you think is the most likely test they will want to do next? Will they use the Rock Abrasion Tool on a juicy piece of sedimentary looking rock, or will they try banging on something with a hammer?

I guess if I were standing there I would try to chip away at the layers to see how resilient they are and if they split along faults, but I'm not sure the rover can do something like that.

Best Regards,

except for the mini-TES, I dont know what' s in the little guys toolbox. Do you? id like to see a troxler gage(uses a gamma source to detn the porosity and relict water content) and an abrasion/ or penetrometer

Your starting to sound like a project manager

"we need more data". hee hee

Layering of a rock with weathering presupposes a stratified structure of the rock at the formation of it.

I wouldnt necc say stratification but lineation satt, there are many differences. One assumes a bit by bit sedimentation at a base level, the other assumes the layering is the preserved position of internal minerals in a ,melt. Some igneous rocks are formed in superposed layers or , as the magma cools the various minerals crystallize out based on pressure and chemical gradients. also, metamorphic rocks can go almost molten and form proto bedding. Look at gneisses or schists.
Im not sure about shocked minerals causing proto layering along rims of craters. Have to consult Gene Shoemakers works on craters. he was the man.

Granites are often formed by a process called anatexis which is the highest temperature achievable while country rock undergoes dynamic metamorphism. The rocks get to be the consistency of hot taffy and are shoved around by tectonics.LAyering or lineation is often preserved There is ample evidence of tectonics on Mars .
of course, with more close inspections, the only bedding we may see is nothing more than the difference between more or less resistance to physical erosion.

Im guessing that these were single sequence igneous rocks with internal mineral lineations. Remember the TES shots of the crater edge? tHE ROcks along the edge all had the same reflectivity with no hint of internal layering

Im more interested in the red to green /blue patches where the balloons touched down. This sez that theres only a thin layer of hematite in this area, and its not in the bottom of the crater. Id like to know the mineralogy of the green/ blue stuff. Is it different? i If so , it demonstrates more modern sedimentation or at least wind borne sedimentation of hematite dust.

It might be a little unreasonable to assume the "lineation" which is based on metamorphism of the rock. The heat by the impact of a meteor should not have lasted very long to cause a "lineation."
It would be much more natural to assume sedimentary processes for the stratification.

satt-I proposed 3 mechanisms that are extra-sedimentary.
Layered igneous - rock exfoliates in erosion, this can often look like layering

metamorphism of the original rock causeing remelting and alignment and lineation of light and dark minerals

impact which causes a localized metamorphism by remelting quartz into lower t/P forms called coesite , stishovite, christobalite and keatite. These forms arewell known to be caused by rapid melting at about 380C, which is well below Alpha quartx melting.
I dont know whether it forms lineations at a crater. Ido know that it is formed in shock quartz layers, , I have to look into ome Shoemaker papers, I recall one where he sampled lots of coesite at the Impact Crater Park.

Lastly, They dont look like sedimentary rocks at all, if you follow the patterns of the minerals specks across the area , youll see that there is no real difference from the more massively broken rock to the rock which has the linear indentations.
Were still looking at multiple hypotheses here. but Im almost ready to rule out purely sedimentary rocks unless these are multiple layers of ignimbrite flows , like welded tuffs. Thats sort of a sedimentary. Theres a layered welded tuff in the Columbia plataeu where theres actually a fossilized megathere (I think an old rhino ) caught in some tuffs

Im not married to any of my ideas. Its just that Ive seen "onion skin" erosion on ignimbritic rocks. Id love for them to be sedimentary but We cannot leap too far when there are more obvious answers that make more geologic sense. Do you or rosborne know whether theres any textual material or prelim interpretations on these outcrops yet?