... but, I must admit that I like very much also this "au revoir" stunning view of Marquette Island ! Enjoy
Click to view attachment

We have an expression like that in English when we find ourselves stopped in an unplanned spot for a long period of time" "good riddance"

Loooong way to Endeavour; Dan, lots more long, unplanned stops along the way.

Wait 'til we find a really big meteorite en-route, you'll be gnawing yer knuckles...!

Thinking: that circle Oppy drew in the dust, to the left side of Marquette Island there, will look nice in a HiRISE image when the orbiter getrs snapping again, won't it?

Vikingmars, that's a very trippy panorama!

Maybe if the meteorite is composed of something like a limestone breccia. In that case I'd say stop and examine it for a while.

Errr... are we leaving MI? Perhaps we're just maneuvering over to look at the east side of it. No drive direction pancams down yet...

Wait everybody! I think it's way too early to say "good bye" to MI.
This move has all the signs of a manouver to either approach another face for further imaging/sniffing or to start a circumnavigation. I'm thinking on the former because the navcams taken to plan the next move (the ones posted on this thread in these last hours) are dead on MI.

The goal is to learn as much as possible about Mars, and a likely piece of the planet from great depth has presented a great learning opportunity. I also suspect we will be here a while longer. A closer look (and maybe a brushing) at some of the other chunks may also be in the offing.

"Fresh Crater" has also become of more interest. It is reasonable to speculate the Fresh Crater is the impact site of the parent body of MI. If so, one would expect to continue to see an ultramafic component of debris as we approach the crater, and less-approaching-zero when we depart from the vicinity on the other side. If a case can thus be made for Fresh Crater being the local impact site, then the crater size and condition, plus an estimate of the ultramafic debris mass, can give good clues as to the origin of MI. But this is speculation, mind you.

Also, it is unclear whether MI has (or can yet be) labeled as a peridotite or rather a gabbro...

Oooooh, nice new view...

Click to view attachment

Did the High Gain Antenna drop off?

Phil

3D view here...

http://twitpic.com/sl7b1

Thanks for those views, Stu. (One good nudge and over she goes. )

If this thing came from the 'fresh crater' impact and was originally part of the impactor there should also be a much larger amount of local sedimentary bedrock amongst the ejecta, but we don't seem to have encountered that yet.

We're starting to see a few wisps of cloud again:
http://qt.exploratorium.edu/mars/opportuni...SGP1553R0M1.JPG
Looks like winter's approaching...

I'm confused. MI is a chunk of rock blasted out of bedrock (from near or far). Looking at images from most sides, it looks like the sides, other than the one brushed, have a bluish (false color) looking crust. The side that was brushed looked to me like a fracture surface newer than the crust. But if it were blasted out of bedrock, the outside would be no different from the inside--unless the outside was heated in the blast, or MI traveled a long way and reentered the atmosphere.

Does anyone else think the brushed side looks fresher than the other sides--and that part of the brushed side was fractured off when it landed at its current spot?

Floyd, I agree that the brushed side looks fresher -- see my post 618, of which the following is an excerpt:



But few others seem to think this is noteworthy.

It's worth keeping in mind that the various sides of MI may have varying amounts of dust on them due to prevailing winds, and that may explain the colour differences of the faces. If we approach a new face of MI it'll be really interesting to brush the dust off a patch and see the real surface.

Olivine (and some of the other components of peridotite) can react with any water to produce a hydrate called Serpentine, which also increases its volume. Even a small amount of moisture adsorbed into MI could cause chemical spalling, which there might be some evidence of in the recent photos. Also note that even coarse grained peridotites and gabbros can exhibit some layering. (The apparent layering could also be just the expression of impact fracturing in the parent body.)

Also, if the local impact of MI's parent was at Fresh Crater, it is less likely that a large fragment of the local soft Sulphate-salt sediment would survive the 350 meter toss from the fresh crater than would the gnarly olivine chunk. We'll obviously see a lot more of the local stuff churned up as we get closer.

(For a definition of Gnarly, see the April 1 edition of Geophysical Letters.)

Thanks for the responses. I particularly like your suggestion of chemical spalling MarkG. Brushing a different surface and some IDD work would provide valuable information, particularly if the faces turn out to have differnet compositions such as Olivine and Serpentine.

It looks like the face right in front of the rover two days ago was not ok.
There was another bump today, sol 2088, to approach the rock by another point and now we have Marquette right within the IDD's workvolume.
Here are fhaz and navcam pictures:
Click to view attachment Click to view attachment

And here's the new navcam view of MI in stereo:
Click to view attachment

The first face may have been fine for grinding but perhaps they decided to look it over -very- carefully and find the most interesting spot possible before burning up those diamonds.

No doubt! The "first face" was clearly the fractured side, and gave the immediate view of the interior. If there's more we can learn from RATing that side, we can go back there. The other sides are well-weathered - perhaps ablated - and may deserve a brushed MI or two. Is any rockhound out there persuaded that this beast is layered? Can't say, myself.
One thing for sure, don't tip it over until you've learned all you want about the back side!

Sol 2089 MI's are down of the new, rougher face of MI:
http://qt.exploratorium.edu/mars/opportuni...TZP2956M2M1.JPG
And here's an anaglyph of the new pancam views:
Click to view attachment

There's something that looks like tiny crystals in this MI
Click to view attachment

Colour view...

Click to view attachment

Yes, actually the whole rock is full of tiny crystals -- mostly of olivine. Gemstone-quality olivine is called peridot.
When an igneous rock is termed "coarse-grained", that means that the size of its component crystalline minerals is macroscopic -- sand-sized or better. That certainly is the case for Marquette Island.
There are also crystals of pyroxene and plagioclase feldspar (according to JPL), plus likely traces of other minerals in MI. On this side of the rock there is also some places where there is some sort of "stuff" in some of indents between grains. This might be pounded-in fine dust, or perhaps deposits of altered olivine (possible "serpentization" hydration of olivine). I did speculate about chemical spalling, perhaps this is evidence. We'll see what this stuff looks like after brushing. I'll bet my rock hammer that they brush this face.

Olivine, feldspar, etc... It seems a lot of the minerals being found are relatively familiar ones on Earth, which is very interesting.



Could olivine form as peridot on Mars? It's a neat green gem, and that would be a cool photo for outreach purposes (though I'm sure the peridot would be dust-caked)...

Olivine and feldspar are (along with pyroxene) the most common minerals in the rocky worlds of the solar system. They're not just on Earth and Mars, they're on the Moon, presumably Venus, and in asteroids and meteorites. It's what you get when you combine the common elements iron, magnesium, calcium, silicon, and oxygen at the low to moderate temperatures and pressures that prevail on the surfaces and in the mantles of these worlds.

That kind of chemical similarity is what you would expect if all the planets (and asteroids) formed from the same protoplanetary disk.

True. I would expect the heavy elements spread pretty uniformly throughout the protoplanetary disk, and thus the plants. t is the volitials that where driven away from the Sun that are more common in the outer Solar System.

OK, thanks. That's interesting.

If I had to guess what those particular crystals were in the MI view, I'd guess garnet. Does that even make sense regarding the major mineral assemblage that has been reported? Would garnet here imply metamorphism of this rock?

My money's on feldspar crystals. Don't know if we'll ever be able to tell for sure, though.

Tomorrow is driving day.
02093::p1212::09::2::0::0::2::0::4::front_haz_ultimate_2_bpp_pri15
...
02093::p1311::07::2::0::0::2::0::4::rear_haz_ultimate_1_bpp_crit15
...

Could you please explain these codes ?

Many thanks.

The key parts are the first number, which is the sol of the sequence, and the "front/rear_haz_ultimate", which means the final hazcam frames that are normally taken after a drive.

I wonder if this just means they've decided to move the IDD to a slightly new spot (recall the arm isn't as maneuverable as it once was). Or maybe they decided to grind into the other side.

The key piece of information in those codes that Tesheiner was referring to was the "ultimate" part -- those identify the hazcam images they take when a drive is over.

The rest of the numbers refer to the number of data products planned vs. expected on the ground. For an explanation of all of this, go check out my class on processing MER and Cassini raw images, downloadable here (even just the Powerpoint may tell you all you need to know)

Squyres mentioned that the rock contains plagioclase feldspar. I think those crystals are apparent in the MIs, but the grains highlighted by Fran are not shaped like typical feldspar crystals.

I'm a little shape-recognition challenged with them, so I'll definitely take your word for it, CR.

Can't see a practical way to make a positive ID, though; Oppy's instrumentation is designed for gross compositional analysis. Guess that some sort of complex silicate is the extreme possibility, since those require liquid water to form.

Here's the answer.
Click to view attachment

And the hortonheardawho MI stitch is here.

Departure to the fresh crater or more certainly just the preparation ?
02094 p1635.03 10 0 0 10 0 20 navcam_5x1_az_54_3_bpp
02094 p2449.20 12 0 0 12 2 26 pancam_drive_direction_4x1_L6R12

Looking to those pictures and today's plan my guess is "bye, bye".


02095::p1154::01::2::0::0::2::0::4::front_hazcam_idd_unstow_doc
02095::p1211::03::2::0::0::2::0::4::ultimate_front_haz_1_bpp_pri_15
02095::p1214::05::2::0::0::2::0::4::front_haz_ultimate_4bpp_pri15
02095::p1254::02::2::0::0::2::0::4::front_haz_fault_pri15_4bpp
02095::p1311::07::2::0::0::2::0::4::rear_haz_ultimate_1_bpp_crit15
02095::p1354::01::2::0::0::2::0::4::rear_haz_fault_pri15_4bpp
02095::p1984::08::2::0::0::2::0::4::navcam_1x1_rvr_az_0_3_bpp_pri_17
02095::p2601::03::4::2::0::0::2::8::pancam_tau_L78R48

Quick stitch, filtering and colourization of 3 Navcams from Sol 2094 (Tues Dec 15 09) - love those wheelies!!

Click to view attachment

It looks like it was just another slight repositioning on sol 2095:
http://qt.exploratorium.edu/mars/opportuni...X7P1214R0M1.JPG

Hmm, check opposite side to determine whether its likely to fall over it pressure is applied, drive back to original side to RAT?

Will make MI position much more visible for MRO

Another quick stitch, process and colourization - this time of NavCams from Sol 2086 (Sun Dec 06 - 09) which are just down from Exploratorium. Wheelies at an earlier stage and that interesting rock M.

Click to view attachment


(Basically trying out new ways of joining Navcams as seamlessly as possible... the variable contrast at the edges of each jpeg doesn't make it easier - lot more to learn yet ).

You may try one of these tools:
http://www.unmannedspaceflight.com/index.p...ost&p=63513
http://www.unmannedspaceflight.com/index.p...ost&p=52870

Thanks T - and shows what a huge resource UMSF has become. I would never have known that those posts existed. Will be fun checking them out over the Christmas break.