Bound water on Mars.

[exoscientist]

Orbiter measurements from the TES instrument on Mars Global Surveyor and the mini-TES intrument on the MER rovers show there are seasonally variable amounts of "bound water" on Mars.<br /><br />Research Articles<br />Initial Results from the Mini-TES Experiment in Gusev Crater from the Spirit Rover. <br />Science 6 August 2004: Vol. 305. no. 5685, pp. 837 - 842.<br />http://www.sciencemag.org/cgi/content/full/305/5685/837 [free full text with registration]<br /><br />GLOBAL MAPPING OF MARTIAN BOUND WATER AT 6.1 MICRONS BASED ON TES DATA: SEASONAL HYDRATION-DEHYDRATION OF SURFACE MINERALS. R. O. Kuzmin1, P. R. Christensen2, and M. Yu. Zolotov2, 1Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 19 Kosygin str., Moscow 119991, Russia, e-mail:****@geokhi.ru, 2Department of Geological Sciences, Arizona State University, Tempe, AZ 85287<br />Lunar and Planetary Science XXXV (2004) 1810.pdf<br />http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1810.pdf<br /><br /> This can be water that is contained within microscopically and nanoscopically small pores in minerals:<br /><br />clay-bound water.<br />http://www.glossary.oilfield.slb.com/Display.cfm?Term=clay-bound%20water<br /><br /> In such a case this water is not in the form of a *chemical bond* to the containing minerals. Essentially this is just water that is only physically trapped within very tiny pores. Is this always the case for "bound water"? <br /><br /> Note the chemical formulas used to represent bound water in hydrated minerals. <br />From the "GLOBAL MAPPING OF MARTIAN BOUND WATER AT 6.1 MICRONS BASED ON TES DATA" report:<br /><br />"Discussion: The results imply the existence of water-bearing surface minerals in a belt surrou <div class="Discussion_UserSignature"> </div>

 

[jaxtraw]

"because its location is farther from the martian equator, which puts it seasonally closer to or farther from the Sun than Opportunity."<br /><br />Eh?!

 

[h2ouniverse]

Great news!<br /><br />This shows the soil is wet.<br />Btw, as temperature increases quickly underground, even with 220K on surface, there are positive temperatures few kms below the surface. So why are people so pessimistic?<br />Regards

 

[JonClarke]

Bound water does not "wet" the regolith. A dry, dusty clay can contain several percent water. <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>

 

[h2ouniverse]

Jon<br />Thanks for the precision.<br /><br />Thought experiment: if the dusty clay is under high pressure, warm temperatures, is there IYO a possibility that part of the water un-binds and generate pockets?<br /><br />Other possibility: there are bacteria recently found in ices that melt a layer of just few molecules of water around their membrane and survive. Would that be possible around a particle of clay?

 

[dragon04]

<font color="yellow">which puts it seasonally closer to or farther from the Sun than Opportunity."</font><br /><br />It would be more accurate to say that a rover at the Martian Equator receives more <b>consistent</b> and direct light.<br /><br />At 135 million miles "downrange", "closer to the sun" doesn't count for much. Especially with respect two two points both being on Mars.<br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[JonClarke]

<i>Thought experiment: if the dusty clay is under high pressure, warm temperatures, is there IYO a possibility that part of the water un-binds and generate pockets?</i><br /><br />The pressures needed would be equivalent to several km of rock. Clays undergone several distinct dewaterings, first when their pore structures collpase (a compact clay at the surface can consist of 60% pore space), then when bound water is expelled, and then when the clays recrystallise to fine-grained micas and feldspars. Lastly the micas break down, but by then to you are several 10's of km deep. I can look up the depths later if people are interested.<br /><br /><i>Other possibility: there are bacteria recently found in ices that melt a layer of just few molecules of water around their membrane and survive. Would that be possible around a particle of clay?</i><br /><br />As far as I know no organism has been demonstrated to be able to extract bound water. But I don't see why bacteria could not extract traces of pore water from clays.<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>

 

[h2ouniverse]

Thanks Jon,<br /><br />For the de-binding by pressure, tens of kms would be too deep for life as we know it IMO = /> the associated temperatures would be of several hundreds of celsius!<br />Unless there are very-high temperature extremophiles... A paradox for Mars!!<br /><br />For walter-layered bacteria = /> your answer clearly rules out any exobio use for bound water.<br />So we are left with pores...