Bound Water on Mars.

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.

Research Articles
Initial Results from the Mini-TES Experiment in Gusev Crater from the Spirit Rover.
Science 6 August 2004: Vol. 305. no. 5685, pp. 837 - 842.
http://www.sciencemag.org/cgi/content/full/305/5685/837 [free full text with registration]

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
Lunar and Planetary Science XXXV (2004) 1810.pdf
http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1810.pdf

This can be water that is contained within microscopically and nanoscopically small pores in minerals:

clay-bound water.
http://www.glossary.oilfield.slb.com/Display.cfm?Term=clay-bound%20water

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"?

Note the chemical formulas used to represent bound water in hydrated minerals.
From the "GLOBAL MAPPING OF MARTIAN BOUND WATER AT 6.1 MICRONS BASED ON TES DATA" report:

"Discussion: The results imply the existence of water-bearing surface minerals in a belt surrounding the edge of seasonal ice caps in both hemispheres, and that these minerals are able to dehydrate and hydrate over the course of the Martian year. Stability of hydrated minerals on Mars (e.g., salts) generally mimics the seasonal stability changes of water ice, as inferred from thermodynamic analyses [16, 19] based on Viking’s surface temperature [14] and the atmospheric H2O abundance [15]. Hydrated minerals are stable at higher temperatures than ice is, which allows their existence beyond the edges of seasonal ice caps. During the winter season in each hemisphere, highly hydrated minerals (e.g., MgSO4·7H2O, Na2SO4·10H2O, MgCl2·6H2O, CaCl2· 6H2O, CaSO4·2H2O) are stable at lower latitudes. In summer seasons, when seasonal ice caps sublimate, less hydrated minerals and anhydrous phases (MgSO4·H2O, Na2SO4, MgCl2·4H2O, MgCl2·2H2O, CaCl2·H2O, CaSO4) become stable at lower latitudes."

Does the H2O attached to the rest of the formula with a dot indicate this water is also only contained within micropores in the mineral and not attached in the form of a chemical bond?

In any case this bound water is able to be released at temperatures that fluctuate at the surface of Mars raising the possibility it could become free liquid water within the right temperature range for the low atmospheric pressures on Mars:

Extreme Planet Takes Its Toll.
June 12, 2007
"Seasonal Change
"During their exploration of Mars, the rovers have recorded temperatures ranging from midday highs of about 35 degrees C. (95 degrees F.) in spring and summer to nighttime lows of about minus 110 degrees C. (minus 166 degrees F.) in winter. Spirit has experienced greater swings in temperature because its location is farther from the martian equator, which puts it seasonally closer to or farther from the Sun than Opportunity."
[link]

And this report gives locations on Mars for which liquid water could be possible for short times seasonally. (The lengths of time given are totals since such water would freeze over at night):

Meteorological Control on the Formation of Martian Paleolakes.
http://adsabs.harvard.edu/cgi-bin/bib_query?2000LPI....31.1509H

Note that as indicated in Fig.1, the Spirit site in Gusev is within the area for which this would be possible for a total of 10 sols, and the Opportunity site at Meridiani is within or near the region where it would be possible for 5 sols. See Fig. 1 here:

Fig.1 Duration (Sols) and location where liquid water could be stable on present day Mars.
http://sciforums.com/attachment.php?attachmentid=3560&d=1101516966

Bob Clark

Thank you, Robert!

Robert,

Thank you as well. The map showing locations of liguid source date 3/2000

Rover data release 8/2004. What thermal data was used in this model?

Darwin

Robert,

Love your work.

Thermals are for real up there.

This is proper stuff that will keep me agog for hours.

Encour.

Spirit:

The location is near 14.8 degrees south latitude, 184.6 degrees west longitude.

[link]

Oppy

image is centered at minus7.8 degrees latitude, 279.5 degrees East longitude.

[link]

If I got the conversions of coordinates from NASA units to the map units, these are correct. Otherwise, please supply me corrected Oppy and Spirit coordinates in map units.

Thanks, Henry

Guys that map is based on the boiling point of 10c.

It is using air temperature not water temperature. If you put a pot of water on a 250f burner it will not boil until the water gets to 212f. There is no water temp data. The map was published in 2000. Old thermal data.

To quote the great Hort, "get out the crayons boys and girls it is play time."

Guys:

Please look at my Reply 4.

I’m uncomfortable with the positions where I marked Spirit and Oppy on the Mars map.

The longitude and latitude which NASA/JPL is different from those used on the map in the article. I attempted a conversion, but just don’t know if it is right.

Please, if anyone can/has made sense of the map coordinates vs. those used by NASA/JPL, please correct me.

Thanks, Henry

Henry, the landing locations for the rovers are:

Opportunity: 354.47E 1.94S
Spirit: 175.48E 14.57S

So the Spirit location as drawn is correct, while Oppy is shown too far west (left). It should be right of the channel shown near the middle of the map - that being the depression of Acidalia Planitia to the north east of the end of the Valles Marineris.

This NASA offering is a better map of the MER landing sites. Not that Oppy is almost dead center on this map, while Spirit is near the right edge just a tad below the equator.

From this CORRECTED MAP, I would have to come to the unexpected conclusion that Spirit is more likely to find standing Martian water than Oppy!

This is pretty interesting, because Spirit recently found Silica (opal-a) also.

Robert, have you seen this article?

http://www.lpi.usra.edu/meetings/lpsc2004/pdf/2188.pdf

Duricrust Formation: At the elevation of the
landing sites of all Mars missions to date, including the
Mars Exploration Rovers, the atmospheric pressure lies
above the triple point pressure of liquid water. At
night, soil and rock temperatures are cold enough (e.g.,
about -100C at the Gusev site) to allow a small amount
of water to condense on or between the grains. In the
"top down" model, this deposited frost is warmed by
the daytime temperature rise to form a transient liquid
phase, which migrates downward (assisted by capillary
action), in the process dissolving any salt present. Surface
tension in the liquid pulls the gains together. As
the soil heats further, the water evaporates, and the
remaining salts cement the grains to form the duricrust.
New aeolean dust and sand brings further material to
the site, allowing the surface crust layer to thicken.

Henry,

That is why there is lots of stuff around rocks. The rocks aint the moma, They are the well.

Darwin

Thanks Henry for the map showing the locations of the rovers with respect to the possible locations of liquid water.
What we need to know also is what are those days during the year when liquid water is possible at the rover sites, and what time of day do they occur.
I was aware of that LPSC report about duricrust formation. it is notable though that that came out in March,2004 while the evidence of frost on Opportunity came out in October,2004.
So the idea of duricrust was mainly just theoretical without a source for the water. With water deposition though now known it provides a legitimate source for water ice that may melt to liquid at the right temperature range.

Bob Clark

Robert, Mars has apparently established a balanced equilibrium for her surface water, between atmospheric water and interstitially-bound water between her surface fines.

The newer track, on the left, will shortly look like the older track, on the right. The passing rover apparently disturbed this equilibrium by locally modifying the interstitial spaces.

Before equilibrium is re-established, I’m sure every allowed phase of water will be passed through, at least microscopically.

The recently-disturbed soil in the left track has caused traces of water in the soil to come to the surface, to temporarily darken the soil. In a few days the low-humidity environment of Mars, and the weak Martian sunlight, will desiccate the track again, and it will soon look like the track on the right.

All this assumes, of course, that squished berries are not the source of the water shown.

Guys,

Brian is saying that all water at Meridiani is bound. Henry says some is not. I think this is a debate that should happen.

Henry’s statement

“A 5.5% by weight of a rock outcrop is a lot of water! Yes, the water may be bound to something, maybe salts, but some of it is apparently in the interstitial spaces between fines grains, too”.

Brian’s statement

“Henry, This is chemically bound”

My question is how can the Mini-TES spectrum segregate what is and what is not bound?

“confirms the presence of an H2 O-bearing phase in the outcrop” Sounds like a wet rock to me.

Darwin

This should go here as well.

Mineralogy of the light-toned outcrop at Meridiani Planum as seen
by the Miniature Thermal Emission Spectrometer and implications
for its formation

Timothy D. Glotch, 1,2 Joshua L. Bandfield, 3 Philip R. Christensen, 3 Wendy M. Calvin, 4
Scott M. McLennan, 5 Benton C. Clark, 6 A. Deanne Rogers, 1 and Steven W. Squyres 7

The emissivity peak at 1630 cm_1 seen in the Mini-TES spectrum of the outcrop-derived fines (Figure 3b) confirms the presence of an H2 O-bearing phase in the outcrop. Conversion of the modeled outcrop mineralogy to chemistry indicates that the total water content of the outcrop is 5.5 wt.%. The only H2 O-bearing phase in the base deconvolution model is kieserite, although both jarosite and nontronite are OH-bearing. Mg-sulfates 11 of 14 with both more and less H2 O than kieserite, and H2 O-bearing Ca-sulfates are not present in the base deconvolution model discussed in Section 4.1, although a separate deconvolution model indicates that bassanite, a hydrated Ca-sulfate may be present in addition to anhydrite. Other water-bearing sulfates absent from the end-member library may also contribute to this bound water detection. In addition to the confirmation of bound water in minerals contained in the outcrop rock, comparison of the outcrop-derived fines spectrum to the GHF spectrum has shown that carbonate concentration in the outcrop rock is close to zero, and that the plagioclase content of the outcrop rock is likely more sodic than that in the GHF

Henry, your "weak Martian sunlight" is around 500 watts per square metre at the rover sites during midday - more than we often see on our cloudy planet - and loaded with the more chemically reactive, shorter wavelength, UV-C and UV-B.

You make a very good point Henry about the difference in appearance between the old tracks and the new tracks.
There have already been several reports about the seasonally variation in the amount of water contained within minerals on Mars, both from orbiter measurements and the rover instruments at the MER landing sites.
It would be a good idea to correlate the visual difference between the old and new tracks and the seasonally varying differences in the mini-TES detections of "bound water".
As I said before this "bound water" detections may or not be in the form of chemical bounds. It may very well be simply water trapped in very times pores in the minerals.
Note though the difference in visual appearance may be because of the larger amount of deposited dust for the older tracks.
Key here then is the fact that the report of frost on Opportunity rover was confirmed by the difference in the appearance in the visual filters in the Pancam images. Frost would be stronger in the blue and weaker in the red, while dust would be the reverse. It was indeed confirmed what the deposition on the rover was stronger in the blue, confirming it as water frost.
See the report on the frost deposition here:

Title: Observation of Frost at the Equator of Mars by the Opportunity Rover.
Authors: Landis, G. A.; Mer Athena Science Team
Publication: 38th Lunar and Planetary Science Conference, (Lunar and Planetary Science XXXVIII), held March 12-16, 2007 in League City, Texas. LPI Contribution No. 1338, p.2423
Publication Date: 03/2007
http://adsabs.harvard.edu/abs/2007LPI....38.2423L

Bob Clark

Note though the difference in visual appearance may be because of the larger amount of deposited dust for the older tracks.

This image is from a1call at

http://gallery.perfext.com/displayimage.php?album=3&pos=38

Robert, the older track, on the right, has dried out some, and I think reveals “white stuff” which is more desiccated material.

Whatever “red Martian dust” which has moved in has done little to kill off the white color, so I suspect there is not much red dust accumulation YET.

Thank you Robert Clark, you always have good stuff.

after enjoying the rover show for years now, and i am still surprised by tidbits that others dig up.

they have only checked ONCE FOR FROST, at each rover site.

Opp. on sol 257 What was the temp spread there Henry?
and
Spirit sol 304.

It takes to much power to heat its instruments.

one for one at opp., whats the chances for that?

Mann,
They didn't check for frost once. They only found it once - at Meridiani.

[link]

Oppy Sol 257 was dead of winter. The air temps in degrees C were (Sol, High Low, Average):

225 3.5307 -78.5683 -37.5188
250 3.5307 -75.63 -36.0497
275 -0.96314 -75.4572 -38.2102

Here is an MI of a berry from Sol 257, partially crusted with what I’ve always thought was ice:

Here are the deg F temps (Sol, High, Low, Average):

225 39.441 -108.075 -34.3168
250 39.441 -102.795 -31.677
275 31.36646 -102.484 -35.559