Mars Rover Spirit Mission Update Thread

[fangsheath]

Clovis certainly has some interesting textures. Parts of it look for all the world like petrified wood. But of greater relevance is the very fine layering it shows. I wish we had gotten some MI's of these areas.

 

[earth_bound_misfit]

That pic reminds me of crazy paving <div class="Discussion_UserSignature"> <p> </p><p> </p><p>----------------------------------------------------------------- </p><p>Wanna see this site looking like the old SDC uplink?</p><p>Go here to see how: <strong>SDC Eye saver </strong>  </p> </div>

 

[fangsheath]

It is still unclear to me exactly what the rover is up to, it drove northward a bit and imaged a small rock with the MI, then spun around to face back southward toward Clovis. Perhaps this was in preparation for some backwards driving toward the north. Anyways, here is another Pancam image of nearby rocks.

 

[Leovinus]

It looks like someone pulled a comb through the sand at the top center of that photo. "Combing the desert" as they say in "Spaceballs". <div class="Discussion_UserSignature"> </div>

 

[mikehoward]

Some very nice navcam images from Sol 228 just showed up on Exploratorium. The view seems to keep getting better! Maybe the air is clearing and the solar power situation will continue to improve. Spirit seems to be moving away from Clovis towards the interesting terrain (looks like your wishes may come true, Fang).<br /><br />http://qt.exploratorium.edu/mars/spirit/navcam/2004-08-24/2N146606200EFF8600P0770R0M1.JPG<br />http://qt.exploratorium.edu/mars/spirit/navcam/2004-08-24/2N146606236EFF8600P0770L0M1.JPG<br /><br />Interesting crater-like depression at the top of the spur: <br />http://qt.exploratorium.edu/mars/spirit/navcam/2004-08-24/2N146606164EFF8600P0770R0M1.JPG<br /><br />My sequence of navcam anaglyphs (wish they were larger): http://homepage.mac.com/michaelhoward/marsupdate/slideshow/2/ana/228/2N146606164_an.htm

 

[jaredgalen]

Are the lighter areas of soilground shown in the background anything significant or of potential interest?<br /><br />http://qt.exploratorium.edu/mars/spirit/navcam/2004-08-24/2N146606657EFF8600P0770R0M1.JPG

 

[fangsheath]

These lighter patches are generally shallow depressions, many of them craters, in which windblown material has accumulated. One of them can be seen more clearly in this Pancam shot. On the other hand, there is a light-colored patch called "home plate" south of Husband Hill that does appear to be rocky. We can't see it from here.

 

[fangsheath]

Spirit is now taking a close look at this rock, which is not too far up the slope from Clovis. There has not been any backwards driving lately as far as I can tell, I get the feeling they are hitting some good spots for charging the batteries while they decide which direction to go next.

 

[fangsheath]

Sorry, wrong pic, this is the one I intended to post. This ridgetop area of West Spur is interesting, we may actually be able to see some of the area east of Lookout Point when we get a bit higher.

 

[fangsheath]

To me the structure of this rock is fairly suggestive of Pot of Gold. There are potential columns of erosion-resistant material within the rock matrix. Many of these seem to have cores of dark-colored material.

 

[fangsheath]

Again there is a curious resemblance here, this low area to me looks for all the world like a dry stream bed. I wish I could post the entire panorama at full resolution, it really gives one a sense of where we are and what's ahead.

 

[the_ten]

Although the anchient ruins I had hoped to see are absent, these are beautiful pictures of another world!<br /><br />Amazing that we're priviledged to see stuff like this in our lifetime!

 

[fangsheath]

Here is a shot of the same area in false color.

 

[mikehoward]

For those with red-blue glasses, here is a pancam anaglyph stitch of the same area.<br /><br />full size: http://img56.exs.cx/img56/4203/Spirit229pa.jpg<br /><br />(Crazy obseration: After staring at this for awhile, and trying to take the tilt into account, I could almost convince myself that the big depression in the middle was a little crater lake, and the part that looks like a dried up riverbed was runoff from it. Okay, that's my last crazy comment for today.)

 

[fangsheath]

This rock, called Ebenezer, resembles Clovis after brushing and Sabre after RATing (to my knowledge Sabre was not brushed prior to RATing). I would be surprised if it doesn't turn out to be another soft rock. I think these are all variations on a theme. The question is, that is the theme? <br /><br />From top to bottom, these are Ebenezer, Clovis, and Sabre. On the left are brushed surfaces, on the right RAT holes.

 

[centsworth_II]

<i>"I think these are all variations on a theme."</i> -- fangsheath<br /><br />The theme of course is alteration. And (of course) the questions about the alteration are how and when. The job of the rover now, according to Steve Squyers is to find unaltered rock in the area for comparison. How it can be determined if the altered rock was identical to the unaltered rock at one time, I don't know. <div class="Discussion_UserSignature"> </div>

 

[fangsheath]

Although these rocks may ultimately be classed as metamorphic (and I am by no means certain of that at this point), I have something much more specific in mind when I say theme. Even assuming they are metamorphic, have they metamorphosed from sedimentary or igneous rock? The implication from Squyres seems to be that they are modified basalts. I don't think so. Basaltic minerals such as olivine and pyroxene are hard. If you take a basalt and soak it in water, you might get a rind of hematite, which is hard, or sulfate, which is soft. What you will not get is a rock with a hard rind and a soft interior, or one that is completely soft, the interior having plenty of chlorides and bromides. Sounds like a sedimentary rock to me, or a metamorphic rock derived from one.<br /><br />To be fair, Squyres is usually careful to use equivocal language, such as "I think" or "We believe at this time." I believe at this time that these hills are loaded with sedimentary rocks that have been heavily modified by the action of water. What Meridiani Planum is telling us is that Mars must have had a much thicker atmosphere at one time. Liquid water was stable on the surface. As Squyres has said, "This was a very different Mars." Not just a very different Meridian Planum. A very different Mars. Rain. Liquid water, on the surface, for substantial periods. Streams, lakes. I see no way around it. The basalt plain we came off of is recent history. The Columbia Hills are telling us a much older, much more watery story.

 

[mikehoward]

Well, that's an exciting speculation! It's clear to me that we are seeing a very different Mars on this mission from what we've seen before, and we're seeing it because of the rovers' basic ability to move around. How much of this science would be happening if Spirit hadn't been able to travel to the hills, or if Opportunity hadn't even been able to roll over to the Eagle crater outcrop? I certainly hope this proves the value of rovers to future mission planners. Why aren't we sending a fleet of MERs (say, four) as our next step in Mars exploration? But I guess that would be a subject for a different thread.

 

[centsworth_II]

It always seemed strange to me that one could expect to find altered and unaltered rock of the same origin side by side. If basalt is found, unless it is in the form of an outcrop, it could simply have been thrown there by an impact event. I hope it can be determined from the data gathered by Spirit what the original composition of the outcrop was and how it was altered. I hope they gather enough information before the mid September break in communications to provide us with an informative press briefing on that subject. <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

Hi centsworth<br /><br />You can decide whether or not an altered rock was originally similar to an unaltered on in a number of ways. One is texture. The other is chemistry. Not all elements move round equally during alteration. Some, like Ti and Zr are relatively immobile, and are called, oddly enough, immobile elements. Comparing the ratios of immobile elements in altered and unaltered rocks can give an indication of the degree of original similarity. Whether the APX is accurate or precise enough for this I do not know.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[thechemist]

Oops !<br />This Ebenezer guy looks softer than goat cheese <img src="/images/icons/smile.gif" /><br />latest RAT <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[fangsheath]

That is actually where the Mossbauer imprinted on the RATed material. Nevertheless, I believe Ebenezer is another soft rock, based on the fact that the RAT operation took only 2 hours and a fairly substantial depth was reached.

 

[JonClarke]

These materials must be so soft they hardly desert the title of rock. More like weakly cohesive or undurated material, not even as hard as dried mud.<br /><br />Parna (wind blown silt) deposits are seeming more and more attractive.<br /><br />Jon<br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[centsworth_II]

Hi Jon, It's good to have you back. Your input is invaluable.<br /><br />Clovis sure <i>looks</i> like a rock. It seems like they could relate the resistance offered to the RAT by a target to a rock hardness scale so that comparisons could be made to other martian rocks and terrestrial analogs.<br /><br />The 2-week communication blackout looms. I hope we're not left in the lurch as to the mineralogical identity of Clovis and other soft 'rocks' on West Spur. A press briefing revealing all that is known to date would be a great way to break up the long wait for communications to resume. <div class="Discussion_UserSignature"> </div>

 

[fangsheath]

Spirit is on the move again, I'm not sure where it's going, but it backed away from Ebenezer after leaving another happy little flower.