Opportunity Mission Update Thread

[thechemist]

How difficult is it to put the APXS on the bright salt and read its composition ?<br /><br />http://qt.exploratorium.edu/mars/opportunity/navcam/2004-10-24/1N151707793EFF3700P1904R0M1.JPG<br /><br />For crying out loud, there are tons of it right next to the rover <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[JonClarke]

Not too difficult I would have thought. I just hope the rover isn't stuck here. There is a degree of ignominy in getting bogged<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>

 

[centsworth_II]

Definately a scary sight! This front hazcam image is a day old. I hope we get another one soon showing the wheel pulled out. <div class="Discussion_UserSignature"> </div>

 

[mikehoward]

Check out these lovely clouds. Looks almost like home.<br /><br />http://qt.exploratorium.edu/mars/opportunity/navcam/2004-10-26/1N152063405EFF37B5P1910L0M1.JPG<br /><br />I sincerely hope both rovers can keep roving indefinitely, but if their mobility systems give out before their optics, they can always spend their retirement years skygazing for us...

 

[fangsheath]

This slope is really a ****** to get up. Despite the fact that there seems to be rock near the surface, much of it is soft and the rover keeps sinking. A lot of soil is caking on the front wheels, reducing traction. We're getting there, slowly and in fits.

 

[thechemist]

Wopmay is upslope from the "Ram", so I guess this makes it less probable they were originally one piece of rock. Unless the rock fell from high and broke on impact. But Wopmay is not covered in sand while the Ram is, so<br />maybe wopmay is part of the rim that fell from somewhere higher ...<br /><br />This is all 100% guesswork of course ... We would have to send JonClark to Mars to find out the truth <img src="/images/icons/wink.gif" /><br /><br /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[JonClarke]

Yes please! <img src="/images/icons/smile.gif" /> <img src="/images/icons/smile.gif" /> <img src="/images/icons/smile.gif" /> <img src="/images/icons/smile.gif" /> <img src="/images/icons/smile.gif" /> <img src="/images/icons/smile.gif" /> <img src="/images/icons/smile.gif" /> <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>

 

[trockner]

If you don't mind my asking, what would cause the soil to become "caked" onto the wheels...as is clear from your sample image?

 

[fangsheath]

Opportunity is making better progress towards Burns Cliff now, as she has reached an area of larger slabs just under the surface with only small cracks between. Looks like they did a "switchback" rather than forcing the rover to go straight up the slope.<br /><br />To answer your question, some, like Gilbert Levin, are convinced that there is moisture there. I am not, although I am not convinced that there is not, either. Some of the cohesiveness of the soil can, I think, be attibuted to electrostatic bonding of small particles. Silt- and clay-sized particles can do this, even in the absence of moisture. But more interestingly, there are indications at both Gusev and Meridiani Planum that the soils contain hydrated sulfate salts deposited by ground water. These hydrated salts will give the soil a certain amount of cohesiveness.

 

[JonClarke]

Fine powders can cake well also. No moisture is needed, alhough a trace (not a lot) certainly helps. When you look at how the front wheels were temporarily bogged, as in centsworth's (picture at the top of the page) the material is behaving like a dry powder, not a mud. Any you can get as bogged in dust as in mud.<br /><br />Cheers<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>

 

[trockner]

Well, it IS interesting that the Euro Mars Express shows much more water vapor in the latitude which Opportunity is operating.<br /><br />See...when I look at the sharply whipped "meringue" feature at the bottom of Endurance I can't help but think this is a frozen water and soil mixture. As far as the "caking" on the rover's wheels, I think there HAS to be some sort of ground loop in the rover design which will allow dangerous static charges to drain back into the relatively higher potentially charged soil.<br /><br />So, therefore, I think I'd have to bank on soil moisture as the cause of the caking.<br /><br />I realize this would open a Pandora's Box of extreme possibilities...but there it is......maybe.

 

[trockner]

JonClarke...if you recall, one of the fears scientists had about landing on the Moon was the possible danger of deep dust swallowing up both men and their equipment.<br /><br />But it was found that soil charging due to the solar wind caused such dust to become highly compacted to the point which it was difficult to even dig into it...even though it led to some nicely sculpted boot-prints.

 

[JonClarke]

Thomas Gold was the prime advocate of that idea. Lunar regolith was much more firmly compacted than he (though not others like Fred Whipple) had predicted for several reasons - it was much more poorly sorted (i.e. lots of small to large rocks), there was vacuum welding from sputtering, and micro meteroite impact glasses. Eectrostatic effects were predicted before hand, but main it as assumed they would form "fairy castles"<br /><br />Cheers<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>

 

[centsworth_II]

<font color="yellow">"...when I look at the sharply whipped "meringue" feature at the bottom of Endurance I can't help but think this is a frozen water and soil mixture." -- trockner</font><br /><br />I assume you are referring to the dune field. I find it easy to see that feature as being fine sand, powder, and dust blown into intricate dunes by prevailing winds. I think it would be impossible to form such structures by wind action if the material were damp. In fact I think the material would have to be VERY dry to be shaped into the fine features seen in the dunes.<br /><br />If you are implying that the dunes were shaped by moving water within the crater, I think the area is much too confined to allow the type of water action that would be required. <div class="Discussion_UserSignature"> </div>

 

[trockner]

I'm not implying that those sculptings were shaped by MOVING water. I think that percolation of water from beneath...through the sand...would lead to those patterns, shaped by rarified/high speed winds and atmospheric sublimation.

 

[trockner]

hmmm...I can maybe see how a micrometeorite rain on an unprotected surface might yield a compaction due to "vacuum sputtering" and "glassy congealing"......but wouldn't such a matrix be continually fractured by the extreme thermal effects of the lunar day/night transitions?<br /><br />Thomas Gold had MANY ideas...some of which I feel he STILL has not been disproven.

 

[JonClarke]

Dry materials are less effected by thermal changes than wet ones (water, even trhaces, greatly adds to rock stress during insolation weathering). Fine-grained materials less than large rocks (conduction rapidly evens the temperature). Subsurface materials are not affected at all (insulation from heat loss and gain).<br /><br />Gold has been proved wrong about lunar dust, the steady state universe, oil and gas. He was right only about neutron stars.<br /><br />Cheers<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>

 

[JonClarke]

<br />As you say, he wandered far from his speciality. No harm in that, but the problem is that he expected to acknowledge his ideas in fields other than his own to be taken seriously. Some did of course, the swedish government spent millions drilling a very deep hole in crystalline basement looking for gas and found nothing of value. Unless you count proof that Gold was a crackpot who new nothing about petroleum geology.<br /><br />The same is true about his theories on the lunar surface. They were interesting in the 50's - athough Whipple had already come up with the correct idea even then. the problem was Gold was still spouting them after Apollo 11 - even after the successful manned landing and all the US and Soviet soft landers and crash landers.<br /><br />Small amounts of methane and other organics can be manufactured abiotically naturally through processes such Fischer-Tropsch synthesis. This is not original to Gold. The idea that economic deposits of oil and gas on earth are produced abiotically is risible. <br /><br />If you want to discuss abiotic oil, perhaps start a new thread, as it would wander far off the topic of this one.<br /><br /><br />Cheers<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>

 

[trockner]

<font color="yellow">This is not original to Gold. The idea that economic deposits of oil and gas on earth are produced abiotically is risible. </font><br /><br />I had to enter that word, "risible", into Google to be sure you weren't misspelling something else.<br /><br />Personally, I think Gold's idea of "abiogenic petroleum" is NOT laughable at all. It makes a lot more sense than trying to invoke dead dinosuars and the swamps they lived in.

 

[JonClarke]

"Risible" is a great word, isn't it? <img src="/images/icons/smile.gif" /><br />Why don't you start a thread in space science and astronomy on a biogenic petroleum and we discuss it there? This is not the place for it. It has been discussed many times before on these boards, although not since the great crash.<br /><br />Cheers<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>

 

[trockner]

Yeah, OK...I'll think about it. Maybe I'll run my Howard Hughes/abiogenic petroleum tale, for the...uhhh..."edification" and/or risibility of the present clientele.<img src="/images/icons/tongue.gif" />

 

[trockner]

How much ability do the rovers have to sense organic gases? I know the Mossbauer instrument can detect elements and simple compounds.<br /><br />I've been exploring the depths of the Hellas Basin recently via MGS imagery and...<br /><br /><img src="/images/icons/cool.gif" />...nevermind.<br /><br />ummm...anyway...there are certainly some spectacular super-dust devil trails down there. I'm guessing the atmospheric pressure must be significantly higher than it is in the upper martian plains...<img src="/images/icons/crazy.gif" />

 

[thechemist]

There is no instrument capable of sensing organic gases on the rovers. It would not make sense to send rovers to study the atmosphere, this can be done via orbiters better.<br />The Mossbauer spectrometer can read various oxidative states of Fe, and the APXS spectrometer and the mini-TES can read the elemental composition of rocks and soil. <br />These are more common on the ground <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[thechemist]

Opportunity has moved considerably forward during the last couple of Sols.<br />I have indicated with a cross its current approximate position in this older forward hazcam image (original) .<br />Oppy's current forward view is here <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[thechemist]

At the top of this NavCam image, we have the first good glimpse of the massive layering on Burn's Cliff.<br />Opportunity must have moved a little bit more forward compared to the image on the post right above.<br /><br />http://qt.exploratorium.edu/mars/opportunity/navcam/2004-11-02/1N152687871EFF37JJP0664L0M1.JPG <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>