Also it would be like trying to drill a marble resting on a stick of butter. I believe the MER-B's RAT was able to expose the interior of some embedded "blueberries", but if these are chert concretions then it would be bloody frustrating trying to open one up. Of course the reward could be great because chert can preserve various goodies....

I wonder if the rock was a hydrated silica or something like a chert, either of which would be very interesting. I think Grotz has actually done research on cherts and organic preservation. Hydrated silica has been detected by CRISM in Hellas Basin and other places on Mars such as Mawrth Vallis. I guess we will not have to wait long to find out....

Speaking of which, I was a little disappointed, as usual, by Irene Klotz's question about the report by the NASA review panel. It is the type of question one would expect by the pop new organizations instead of someone who is supposed to be a science reporter. How about a question about a technical issue such the resistance of certain classes of organics to cosmic rays (PAHs for instance)? Or the geology of Pahrump Hills? Or the reagent issue in SAM?

Which subtle thing is that? The DRT seems to have some aberrant bristles sticking out? Is that it?
I do not see the wayward bristles in this photo from Honeybee:
http://www.honeybeerobotics.com/portfolio/dust-removal-tool/

I would think that if it is caused by combusting organics then there should be some partial combustion products produced also...

Would anyone care to elaborate on the SAM CO2 findings? Mahaffy noted that the CO2 peak could have been cause either by the oxidation of carbon compounds or from carbonates. I would think that either of these possibilities is rather significant.

I would be in no great rush to leave such a geologically rich area. Besides what if Mt. Sharp turns out to made of aeolian deposits instead of water-borne sediments? [I suspect that Mt Sharp is not aeolian at the base, only the upper layers.]

The comments accompanying Craig Covault's article are discouraging to say the least. Science writers (myself included) need to do a better job communicating what is happening with this mission and why it has been so successful so far. There is a lot of unwarranted negativity in those comments such as complaining about the cosmic ray hit when they should be complimenting the team on having the foresight to have a backup mirror computer.

Does this mean that RAD will not be operational? Too bad; such measurements would be very interesting.

Anyone have a vacuum chamber and some clay-y mud?

Also I have to wonder what would happen to a carbonate / mud mix when sulfuric acid percolates through it. I would think that CO2 would bubble out it...

I found the mention of X-ray Fluorescence in the article rather interesting. I had thought that the ChemMin XRF requirement for MSL had been descoped. But it appears that some XRF (using transmission geometry instead of reflected geometry) will still be possible (http://msl-scicorner.jpl.nasa.gov/Instruments/CheMin/):
"This requirement [XRF] was amended when the Si-PIN diode for reflection-geometry XRF was descoped from the proposed design. Quantitative XRF analysis of elemental composition is now only a “best effort” task dependent on progress in element quantification using only the transmission geometry. "

Viking 2 actually photographed ground frost at Utopia Planitia (http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/vl2_22e169.html). Much higher latitude though....

Let's not get too carried away; MSL does have finite limits on instruments and resources. The ChemMin specification (D. Blake et al) notes: "During the nominal MSL mission of one Mars year, the ChemMin CCD will be damaged by high-energy neutrons from the nuclear power source..." so performance will degrade after that (although steps to ameliorate this have been taken). There are a bunch of other limits, some more serious than others. Off the top of my head here are few: There is a limit to the amount of helium carrier gas MSL carries. Residue may accumulate in the quartz cups but that may not be a problem. And there is a limited supply of solvents in the wet cells limiting the amount of polar (i.e. amino acids) chemical extractions that can be done.

Hopefully MSL will last long enough to come up against these limits for even if it is half-blind (as Opportunity is now) with a degraded ChemMin CCD and depleted wet cells etc., it is still an incredible machine. I sure hope the MSL nominal mission of one Martian year is as accurate as the 3-month estimated lifespan of the MERs. JPL has an excellent track record so I am very hopeful.

As far as Mt. Sharp, Matthew Golombek noted in an excellent pre-landing briefing that MSL will not travel above the sulfate layers because it is thought that area is dominated by soft aeolian deposits.

Can we discuss SAM's stereochemistry capabilities? I believe that SAM can sort out chirality, but I have seen very little written about this. As we all know, stereochemistry would allow us to help us determine, ah I hesitate to say this, the genesis of some organics. As far as I can tell, SAM can determine if a peak is chiral, but I am not sure if it can tell if there is a preponderance of L- versus D- for a particular organic chemical.

This is not LOL funny but I got a smile out of it:

Before EDL JPL produced this delightful video describing the MSL mission. What I found interesting is that JPL found a narrator that sounds somewhat like Dr. Carol Marcus from The Wrath of Khan (when she is describing the Genesis Project):
http://www.youtube.com/watch?v=GUQ91fdYbP4

Here is Dr Carol Marcus (poor quality alas):
http://www.youtube.com/watch?v=Tsr-XtuKuSw