Opportunity Mission Update Thread

[marslauncher]

http://qt.exploratorium.edu/mars/opportunity/navcam/2004-07-15/1N143189076EFF3243P1920L0M1.JPG<br /><br />Nice view on how far we have gone.

 

[marslauncher]

Cant wait for the mission briefing tomorrow

 

[thechemist]

Here is a fresh close-up of the "half-dome-shaped rock"<br />http://qt.exploratorium.edu/mars/opportunity/pancam/2004-07-16/1P143185259EFF3221P2397R1M1.JPG<br /><br />From the way it is eroded more on the base and less higher up, and the ever-present-in-cracks clear thin sand in front of it, it appears to me more likely something liquid did the trick, and not wind. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[centsworth_II]

I don't know much about the details of erosion processes, but I imagine that dust trapped at the base of the rock and contunually stirred up against it by wind could create the undercut. I hope Opportunity can see into the shadows well enough to get a good look at the surface of that half-dome.<br /><br />By the way, I am totally shocked and surprised at how fast the rover got to the "fence" and "half-dome". I was hoping to hear at today's briefing that they were intending to go that far. And now, they already have! WOW! <div class="Discussion_UserSignature"> </div>

 

[thechemist]

I have previously mentioned I consider myself "geologically-challenged" <img src="/images/icons/smile.gif" />, so my opinion on such matters should be taken lightly.<br />Having cleared that, I think the topography in Endurance may not be adequately accounted for without some kind of liquid flowing inside the crater at some point in time. This is my personal non-scientific opinion.<br /><br />With respect to Oppy's fast "climbing of the fence", I was also surprised ! Nasa web updates are a week back (yesterday they updated Oppy to Sol 163, it is Sol 170 today). At least images are available almost in real time, so we know what Oppy is up to <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[jaredgalen]

Just realised, the rovers broke the 40,000 images mark. <br />Sweet.

 

[thechemist]

In the shadow of the "dome":<br />Edit: It's "half-dome" and this is the original image <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[centsworth_II]

Interesting look at the face of the dome. I wonder if they'll look at it with the micro-imager and the other instuments.<br /><br />Hey! At the press briefing, the possible method of creation of the "fence", or what they call "razorback" was given, and it involved water! <i>Water in the crater after its creation!</i> This surprised me (although apparently not you). I really hadn't thought about Endurance crater being exposed to water.<br /><br />The possible explanation given was that water deposited minerals in cracks, formed during the impact that created Endurance. The mineral that formed in the cracks is harder than the surrounding rock and the rock is eroded away leaving the razorback-shaped mineral that once filled the cracks in the rock. They are trying to figure out out to get the rover instuments onto the mineral formations to analyze them. <div class="Discussion_UserSignature"> </div>

 

[thechemist]

What great news ! How could I have missed this brief <img src="/images/icons/frown.gif" /><br />Thanks for filling up the info gap centsworth_II !<br />I 'll try to find the text and catch up replays in NasaTV.<br />If it is confirmed that water formed some of the rock layers, and (much ?)later it was also involved in eroding them, it seems to me that its presence might be a long one in Endurance. This is fantastic news <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[centsworth_II]

<i>"If it is confirmed that water formed some of the rock layers, and (much ?)later it was also involved in eroding them, it seems to me that its presence might be a long one in Endurance."</i><br /><br />I think they are still considering the erosion as being wind driven. But still, the fact that water was involved in mineral deposition in the crater shows water at work both before Endurance was created and after. That is still fantastic news, and surprising to me. <div class="Discussion_UserSignature"> </div>

 

[thechemist]

Oppy has moved lower down the crater, and has crossed the "fence" <img src="/images/icons/smile.gif" /> (you see, it sounds much better than "crossed the razorback", that sounds too dangerous <img src="/images/icons/smile.gif" /> )<br />This is a Forward Hazcam image from Oppy's new position , with half of the razorback feature visible (middle, right), the other half is in the dark.<br /><br />In the image below, Oppy's new approx. position is indicated with a white square, the arrow showing the forward direction.<br /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[thechemist]

From the July 16 press release: <br /><br /><blockquote><font class="small">In reply to:</font><hr /><p> Probing increasingly deep layers of bedrock lining the walls of Endurance Crater at Meridiani Planum, the rover has observed a puzzling increase in the amount of chlorine. Data from Opportunity's alpha particle X-ray spectrometer show that <font color="yellow"> <i> chlorine is the only element that dramatically rises with deepening layers </i> </font> leaving scientists to wonder how it got there. "We do not know yet which element is bound to the chlorine," said Dr. Jutta Zipfel, a rover science-team member from the Max Planck Institute for Chemistry, Mainz, Germany. <p><hr /></p></p></blockquote><br /><br />Since the APXS spectra can observe most of the possible cation partners of Cl- (Na, Mg, Ca, Al, Si, Fe, etc..) does the above imply some other element might be the cation for Cl- deep in Endurance ?<br />The quote emphasizes that none of the above cations increases with depth.<br />Any salts/rocks suggestions possesing exotic cations JonClark ? <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[centsworth_II]

I wonder what the chances are of there being more than one chlorine compound present. That would complicate things, I imagine. <div class="Discussion_UserSignature"> </div>

 

[fangsheath]

If the chlorine concentration is increasing and no particular cation is increasing accordingly, I would say the chance is near 100%. There have to be different chlorides contributing the chlorine to produce this distribution, I see no alternative. Cations commonly observed at Eagle Crater included sodium, magnesium, potassium, calcium, manganese, and iron. Corresponding chlorides on earth might include halite (sodium chloride), silvite (potassium chloride), rinneite (potassium sodium iron chloride), scacchite (manganese chloride), and carnallite (hydrated calcium magnesium chloride). This by no means exhausts the possibilities.

 

[fangsheath]

I would add that on earth, sylvite and carnallite are often among the last minerals to form from the evaporation of sea water. Halite tends to form before these.<br /><br /><br /><br />

 

[fossils]

Dunes created by a resonating air over the crater... LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL LOL<br /><br />http://qt.exploratorium.edu/mars/opportunity/pancam/2004-07-21/1P141244359EFF3190P2571L7M1.JPG<br />

 

[JonClarke]

Absolutely exquiste textures to those dunes. They way they appear shine is interesting, it seems to be an extreme contrast effect between the illuminated back and the shadowed front of the dunes. I wonder if they could perhaps be cemented or coated by some mineral crust that enhances the natural lighting contrast. We don't see ythis in dunes at other sides - Viking 1, Pathfinder, Spirit. But the dune particles themselves could be compositionally different as well.<br /><br />Jon<br /><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>

 

[exoscientist]

TheChemist, the news release doesn't *specifically* say these metals don't increase along with the chlorine though it does imply it.<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

Another possibility might be the chlorine is combined with lighter elements that the APXS can't detect, such as oxygen, nitrogen or hydrogen.<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

Just saw the APXS can detect light elements such as carbon and oxygen in the alpha mode. <br /> I don't know if this has been done yet or if it can detect nitrogen and hydrogen.<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[silylene old]

Jon, if you look closely, there are small "wavelets" on the backslopes of some of the dunes.<br /><br />I do agree, there does seem to be a weird shiny-ness or hardness to the dunes. And some of the dune pictures also show a strange vertiacal "interfacial junction" between the dune and the rock substrate, which is suggestive of a hardening.<br /><br />Becuase of the observation of small wavelets on some of the dunes, if the dunes are coated with a mineral crust, I suggest that there is likely a thin layer of sands on top of the crust which is free to blow around. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[thechemist]

Hello there Silylene,<br />An image of the wavelets to get the discussion heat-up.<br />What about NH4Cl as a salt for Endurance ?<br />Would it be detected by AXPS ? <br />Edit : added some details:<br /> sal ammoniac = ammonium chloride <br /><font color="yellow"> <i> "Sal ammoniac forms on <b> volcanic rocks </b> near fume releasing vents. There is no liquid phase as the mineral crystallizes from these fumes in a process called sublimation. The crystallization occurs as the gases are escaping and crystals tend to be short-lived. Sal ammoniac is very soluble in water and crystals will be removed during the first rain of their existence, so to speak, if they are not removed by collectors first." </i></font> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[fangsheath]

Not to deflect attention from the beautiful ripples/dunes, but here is a microscopic image of one of the "razorback" elements.

 

[JonClarke]

Yes, aren't they gorgeous? Of course the ripples could be cemented as well. I hope that the rover gets that far down.<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>

 

[silylene old]

<i>What about NH4Cl as a salt for Endurance ? </i><br /><br />I don't think so, because NH4Cl is thermally unstable. Embedded in a polymer film, about 10 mg of it will thermally degrade at 50C in about 60 seconds. We use it as a thermal acid generator in one of our products.<br />NH4Cl + heat ---- /> NH3(gas) + HCl (gas)<br />My guess is, even at sub-zero temperatures, it would completely degrade and sublime away over the years. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>