Mars Odyssey hydrogen-content measurements have shown seasonal deposition of water/ice on Mars even at equatorial locations. This has been confirmed by the Opportunity rover in Meridiani by the observation of early morning frost on the rover:
More on "Frost on the rover solar panels".
http://bautforum.com/showpost.php?p=323577&postcount=6
This deposition of frost at Meridiani corresponded to the observation of clouds over the site during the local Winter:
Mars Rovers Spot Water-Clue Mineral, Frost, Clouds.
13-Dec-2004
http://marsrovers.jpl.nasa.gov/gallery/pre.../20041213a.html
Since clouds have also been seen over the site during the current Summer season, I argue this should also correspond to water/ice deposition currently at the Meridiani landing site:
Space Sciences
Summer clouds over Meridiani?
Posted by Robert Clark on 12/31/2005 6:56:40 PM
http://habitablezone.com/space/messages/409185.html
The "Mars Rovers Spot Water-Clue Mineral, Frost, Clouds" press release showed the frost forming in early morning in the Winter season. The image of the frost was taken 11 minutes after sunrise, and a subsequent image showed the frost had burned off 3 hours later due to rising temperatures.
Perhaps the clouds in the images in the current season appear at night because of the coldness at night during this current Summer period. Then we might expect the greatest water/ice deposition to also occur at night.
Could the mini-TES detect H2O on the rover at night? Could we for example compare the spectra at night to the morning spectra?
Another experiment I suggest to try would be to press down with the RAT at night and keep the area covered till early morning. Then uncover the area soon after sunrise to see if there are any remaining signs of moisture.
This may have what occurred at the Gusev landing site with the Spirit rover landing bags with the observation of the "magic carpet" mud-like material. The Gusev landing occurred within the period that the Mars Odyssey readings showed the greatest water/ice deposition occurs during southern Summer. Then the landing bags covering the soil may have allowed deposited water/ice to be retained against sublimation/evaporation. When the bags were pulled away, moist soil would have been revealed.
That this deposition occurs may provide a means of obtaining water for consumption or fuel (hydrogen through electrolysis) by future manned missions. The method of a "solar still" allows water vapor in the air to be collected and condensed to liquid water even in desert regions:
Desert Survival
Collect Water in a Solar Still.
http://www.desertusa.com/mag98/dec/stories/water.html
Bob Clark
Full Version: Could We Make A "solar Still" On Mars?
Bob:
Interesting thoughts - and, personally, I can see no way *not* to use solar stills on Mars - they're cheap, simple and require little maintenance.
As for the 'Magic Carpet' - interesting explanation, and I suppose the proof of the pudding lies in just how long the soil was covered...
Bob Shaw
Interesting thoughts - and, personally, I can see no way *not* to use solar stills on Mars - they're cheap, simple and require little maintenance.
As for the 'Magic Carpet' - interesting explanation, and I suppose the proof of the pudding lies in just how long the soil was covered...
Bob Shaw
QUOTE (Bob Shaw @ Jan 4 2006, 01:58 PM)
Interesting thoughts - and, personally, I can see no way *not* to use solar stills on Mars - they're cheap, simple and require little maintenance.
It would help, of course, if there was a non-negligible amount of water vapor in the atmosphere.
Typical water vapor column densities in Antarctica are around 600 precipitable microns, 6X the maximum value observed on Mars and something like 40X more than the typical martian values. Column densities in martian ground fogs are even smaller -- see http://www.aas.org/publications/baas/v34n3/dps2002/158.htm
It'd be interesting to know if using a solar still in Antarctica would be worth the effort.
QUOTE (mcaplinger @ Jan 4 2006, 11:27 PM)
It would help, of course, if there was a non-negligible amount of water vapor in the atmosphere.
Typical water vapor column densities in Antarctica are around 600 precipitable microns, 6X the maximum value observed on Mars and something like 40X more than the typical martian values. Column densities in martian ground fogs are even smaller -- see http://www.aas.org/publications/baas/v34n3/dps2002/158.htm
It'd be interesting to know if using a solar still in Antarctica would be worth the effort.
Typical water vapor column densities in Antarctica are around 600 precipitable microns, 6X the maximum value observed on Mars and something like 40X more than the typical martian values. Column densities in martian ground fogs are even smaller -- see http://www.aas.org/publications/baas/v34n3/dps2002/158.htm
It'd be interesting to know if using a solar still in Antarctica would be worth the effort.
I'd expect a still to be exploiting the moisture in the always-cool ground by heating the atmosphere above it, driving water off the ground surface (to be replenished from below), cooling off that atmosphere, and collecting dew. We can *see* hoar frost, for goodness sake!
Bob Shaw
QUOTE (mcaplinger @ Jan 4 2006, 10:27 PM)
It would help, of course, if there was a non-negligible amount of water vapor in the atmosphere.
Typical water vapor column densities in Antarctica are around 600 precipitable microns, 6X the maximum value observed on Mars and something like 40X more than the typical martian values. Column densities in martian ground fogs are even smaller -- see http://www.aas.org/publications/baas/v34n3/dps2002/158.htm
It'd be interesting to know if using a solar still in Antarctica would be worth the effort.
Typical water vapor column densities in Antarctica are around 600 precipitable microns, 6X the maximum value observed on Mars and something like 40X more than the typical martian values. Column densities in martian ground fogs are even smaller -- see http://www.aas.org/publications/baas/v34n3/dps2002/158.htm
It'd be interesting to know if using a solar still in Antarctica would be worth the effort.
Good question about Antarctica. A problem with forming the still there would be having temperatures above the freezing point being reached.
Note though there are locations in Antarctica that reach water vapor amounts comparable to that of Mars:
South Pole Transmissivity Plots.
"Because of its high altitude, low water vapor column, and low
temperatures, Antarctica may contain some of the driest and thus best
sites for infrared, submillimeter, and millimeter astronomy [Bally,
1989; Harper, 1989; Chamberlin and Bally, 1996]. Potential sites on the
Antarctic plateau vary in elevation from nearly 3000~m to over 4000~m.
The center of the plateau is in a permanent high-pressure zone where
air is descending from high altitudes. Temperatures at the south pole
range from 200~K to 260~K [Chamberlin and Bally, 1994]. Measurements of
the precipitable water vapor column [e.g., Smythe and Jackson, 1977;
Burova et al., 1986] show that the water column can be as low as 50
microns in the austral winter, and is rarely above 1~mm."
http://casa.colorado.edu/~bally/AT/cara.html
Note though that it is very likely some fog covered sites have significantly more water content than the 100 microns frequently sited as the Mars maximum:
Clouds in Noctis Labyrinthis.
"This image shows early morning fog in the Noctis Labyrinthis, at the westernmost end of Valles Marineris. This fog, which is probably composed of water ice, is confined primarily to the low-lying troughs, but occasionally extends over the adjacent plateau. The region shown is about 300 kilometers (186 miles) across."
http://www.solarviews.com/cap/mars/noctis.htm
Bob Clark
QUOTE (RGClark @ Jan 4 2006, 04:37 PM)
Note though there are locations in Antarctica that reach water vapor amounts comparable to that of Mars...
Note though that it is very likely some fog covered sites have significantly more water content than the 100 microns frequently sited as the Mars maximum:
Note though that it is very likely some fog covered sites have significantly more water content than the 100 microns frequently sited as the Mars maximum:
You're reversing my point about Antarctica -- I am simply skeptical that even 10x more water than on Mars, what is seen in the Dry Valleys, would be a useful resource for exploration.
As for fog-covered sites -- you are looking at a picture and simply assuming that there must be a lot of water vapor in it. If you read the link I cited above, you will see that fogs can be formed by nucleation on dust particles at very low column densities -- under 1 micron.
All that said, I concede that there is water on Mars, maybe even transient liquid water/brine at some times and seasons and certainly frost. I don't think anyone finds that controversial. But there isn't enough in the atmosphere to be practical as an exploration resource, and I don't think it implies anything especially favorable about the possibility of extent martian life.
QUOTE (mcaplinger @ Jan 5 2006, 12:53 AM)
You're reversing my point about Antarctica -- I am simply skeptical that even 10x more water than on Mars, what is seen in the Dry Valleys, would be a useful resource for exploration.
As for fog-covered sites -- you are looking at a picture and simply assuming that there must be a lot of water vapor in it. If you read the link I cited above, you will see that fogs can be formed by nucleation on dust particles at very low column densities -- under 1 micron.
All that said, I concede that there is water on Mars, maybe even transient liquid water/brine at some times and seasons and certainly frost. I don't think anyone finds that controversial. But there isn't enough in the atmosphere to be practical as an exploration resource, and I don't think it implies anything especially favorable about the possibility of extent martian life.
As for fog-covered sites -- you are looking at a picture and simply assuming that there must be a lot of water vapor in it. If you read the link I cited above, you will see that fogs can be formed by nucleation on dust particles at very low column densities -- under 1 micron.
All that said, I concede that there is water on Mars, maybe even transient liquid water/brine at some times and seasons and certainly frost. I don't think anyone finds that controversial. But there isn't enough in the atmosphere to be practical as an exploration resource, and I don't think it implies anything especially favorable about the possibility of extent martian life.
My intent actually was to use the phenomenon of a "solar still" as a point of departure to argue that we may be able to observe liquid water at the landing sites during the current Summer season by covering a small patch on the surface until the early morning. Note we might already be seeing an example of this. See the MI images here:
Erebus Outcrops.
http://www.markcarey.com/cgi-bin/mt/mt-vie...art=376&show=20
The flattened areas have a mushy appearance to them. Another check for this might be to perform a RAT observation early in the morning where there might be residual moisture left and compare this to a RAT observation of a spot nearby later in the afternoon when moisture would be expected to burn off.
Would there be a difference in the appearance in the two RATted areas?
In regards to the amount of water in fog, I'm arguing the amount of water in for example the Noctis fogs is significantly greater than 100 precipitable microns because of the density of the fogs. The fogs above the Pathfinder site were nowhere near this density.
Bob Clark
QUOTE (RGClark @ Jan 4 2006, 10:45 PM)
In regards to the amount of water in fog, I'm arguing the amount of water in for example the Noctis fogs is significantly greater than 100 precipitable microns because of the density of the fogs.
If you had some analysis to support this (using phase angles of the illumination, optical depth, scattering properties of the droplets, and factoring in dust loading) then the idea might be plausible. As it is, it's just based on your intuition, isn't it? Direct observation of H20 absorption bands of these areas with TES has shown no unusually high column density.
QUOTE (mcaplinger @ Jan 5 2006, 04:34 PM)
If you had some analysis to support this (using phase angles of the illumination, optical depth, scattering properties of the droplets, and factoring in dust loading) then the idea might be plausible. As it is, it's just based on your intuition, isn't it? Direct observation of H20 absorption bands of these areas with TES has shown no unusually high column density.
I don't want to restate the blindingly obvious, but no matter whose figures you choose to apply, we've all seen the pictures of hoar frost.
Looks like, er, water, to me...
Bob Shaw
QUOTE (RGClark @ Jan 5 2006, 01:45 AM)
My intent actually was to use the phenomenon of a "solar still" as a point of departure to argue that we may be able to observe liquid water at the landing sites during the current Summer season by covering a small patch on the surface until the early morning. Note we might already be seeing an example of this. See the MI images here:
...
In regards to the amount of water in fog, I'm arguing the amount of water in for example the Noctis fogs is significantly greater than 100 precipitable microns because of the density of the fogs. The fogs above the Pathfinder site were nowhere near this density.
Bob Clark
...
In regards to the amount of water in fog, I'm arguing the amount of water in for example the Noctis fogs is significantly greater than 100 precipitable microns because of the density of the fogs. The fogs above the Pathfinder site were nowhere near this density.
Bob Clark
The thread seems a bit confused (or at least i am). However, in response to a few atmospheric/MiniTES issues:
1) it is unlikely that MiniTES would be able to see water ice lines in the amount of frost because of
the temperature of the surface (i.e., thermal contrast) and the amount of frost present.
2) 100 pr-micron of water is a number quoted for the north polar region when the seasonal cap is
subliming. this is not a useful number for general consideration in the tropics unless one is invoking
a very, very, very localized source of water vapor (i.e., one that could hide from orbital remote sensing
during the day or be "smeared out" over a TES footprint).
3) even a few pr-micron of fog (i am assuming that a fog is in the bottom scale-height of the atmosphere) would be clearly detectable by mini-TES. the detetection-limit for water-vapor is probably
in the 5-10 pr-micron region due primarily to tiny size of the lines on the longwave side and signal-to-noise issues on the shortwave side (as well as aeorsol scattering swamping any H2O radiance).
4) it is difficult to imagine that the amount of water needed to create a "mushy" morphology wouldn't
be detectable with a bound-water signature even during the day. if you have to "burn it all off" during
the day and bring it back at night, there are implications for the regional distribution of water which would make it more likely to be detected from orbit (not to mention from the rovers).
5) as pointed out by mcaplinger, it is not reasonable to assume that the beautiful fogs in the Noctis
images require anything more than a few pr-microns at most. the very large single scattering albedo
and illumination geometry make it very easy to get such a photometric effect withouth needing optically
thick ice fog. the aphelion cloud belt can reach general optical depths (away from volcanoes, and in the
visible) of a few tenths...and even that only requires around 1 pr-micron.
i guess if you are interested in solar stills, there are probably better regions on Mars to consider if
50-100 pr-micron is what you need. if you want liquid water, you will want to consider the geochemical
implications (i.e., they use mini-TES on any rock they RAT). there is also the work of Haberle and collaborations which illustrate the "locations" on Mars where liquid water could exist at the surface under
current martian conditions (using a GCM tuned to Viking surface pressure measurements, not water vapor distribution and transport).
QUOTE (RGClark @ Jan 5 2006, 01:45 AM)
In regards to the amount of water in fog, I'm arguing the amount of water in for example the Noctis fogs is significantly greater than 100 precipitable microns because of the density of the fogs. The fogs above the Pathfinder site were nowhere near this density.
Bob Clark
Bob Clark
I forgot this one. What do you mean by "density"? the spatial extent? the implication of your statement is that there must be a more concentrated source that provides the spatially extended structure. is this the
case? transport over that scale would make it difficult to hide a 100 pr-micron+ source that wouldn't
be detected by TES water vapor measurements. have i misunderstood your use of "density"?
RGClark,
Your idea is damned good -- I think one of the very best, among many others, to have popped up on Unmanned Space Flight. And perhaps even a long-term contribution to the future exploration and even colonization of Mars.
Glenn Smith
Your idea is damned good -- I think one of the very best, among many others, to have popped up on Unmanned Space Flight. And perhaps even a long-term contribution to the future exploration and even colonization of Mars.
Glenn Smith
QUOTE (mwolff @ Jan 16 2006, 05:12 PM)
The thread seems a bit confused (or at least i am). However, in response to a few atmospheric/MiniTES issues:
1) it is unlikely that MiniTES would be able to see water ice lines in the amount of frost because of
the temperature of the surface (i.e., thermal contrast) and the amount of frost present.
2) 100 pr-micron of water is a number quoted for the north polar region when the seasonal cap is
subliming. this is not a useful number for general consideration in the tropics unless one is invoking
a very, very, very localized source of water vapor (i.e., one that could hide from orbital remote sensing
during the day or be "smeared out" over a TES footprint).
3) even a few pr-micron of fog (i am assuming that a fog is in the bottom scale-height of the atmosphere) would be clearly detectable by mini-TES. the detetection-limit for water-vapor is probably
in the 5-10 pr-micron region due primarily to tiny size of the lines on the longwave side and signal-to-noise issues on the shortwave side (as well as aeorsol scattering swamping any H2O radiance).
4) it is difficult to imagine that the amount of water needed to create a "mushy" morphology wouldn't
be detectable with a bound-water signature even during the day. if you have to "burn it all off" during
the day and bring it back at night, there are implications for the regional distribution of water which would make it more likely to be detected from orbit (not to mention from the rovers).
5) as pointed out by mcaplinger, it is not reasonable to assume that the beautiful fogs in the Noctis
images require anything more than a few pr-microns at most. the very large single scattering albedo
and illumination geometry make it very easy to get such a photometric effect withouth needing optically
thick ice fog. the aphelion cloud belt can reach general optical depths (away from volcanoes, and in the
visible) of a few tenths...and even that only requires around 1 pr-micron.
i guess if you are interested in solar stills, there are probably better regions on Mars to consider if
50-100 pr-micron is what you need. if you want liquid water, you will want to consider the geochemical
implications (i.e., they use mini-TES on any rock they RAT). there is also the work of Haberle and collaborations which illustrate the "locations" on Mars where liquid water could exist at the surface under
current martian conditions (using a GCM tuned to Viking surface pressure measurements, not water vapor distribution and transport).
1) it is unlikely that MiniTES would be able to see water ice lines in the amount of frost because of
the temperature of the surface (i.e., thermal contrast) and the amount of frost present.
2) 100 pr-micron of water is a number quoted for the north polar region when the seasonal cap is
subliming. this is not a useful number for general consideration in the tropics unless one is invoking
a very, very, very localized source of water vapor (i.e., one that could hide from orbital remote sensing
during the day or be "smeared out" over a TES footprint).
3) even a few pr-micron of fog (i am assuming that a fog is in the bottom scale-height of the atmosphere) would be clearly detectable by mini-TES. the detetection-limit for water-vapor is probably
in the 5-10 pr-micron region due primarily to tiny size of the lines on the longwave side and signal-to-noise issues on the shortwave side (as well as aeorsol scattering swamping any H2O radiance).
4) it is difficult to imagine that the amount of water needed to create a "mushy" morphology wouldn't
be detectable with a bound-water signature even during the day. if you have to "burn it all off" during
the day and bring it back at night, there are implications for the regional distribution of water which would make it more likely to be detected from orbit (not to mention from the rovers).
5) as pointed out by mcaplinger, it is not reasonable to assume that the beautiful fogs in the Noctis
images require anything more than a few pr-microns at most. the very large single scattering albedo
and illumination geometry make it very easy to get such a photometric effect withouth needing optically
thick ice fog. the aphelion cloud belt can reach general optical depths (away from volcanoes, and in the
visible) of a few tenths...and even that only requires around 1 pr-micron.
i guess if you are interested in solar stills, there are probably better regions on Mars to consider if
50-100 pr-micron is what you need. if you want liquid water, you will want to consider the geochemical
implications (i.e., they use mini-TES on any rock they RAT). there is also the work of Haberle and collaborations which illustrate the "locations" on Mars where liquid water could exist at the surface under
current martian conditions (using a GCM tuned to Viking surface pressure measurements, not water vapor distribution and transport).
Thanks for the contribution to the board. I'll think about the miniTES readings and respond to that later. But in regard to the fogs, I don't think there has been any estimate for the amount of these fogs over Noctis. Clearly, the amount of water in any fog or cloud is going to be different depending on the density of the fog/cloud. I agree the estimates for the fogs over Pathfinder were quite low, I just think the Noctis fogs are a different matter in quantity and quality.
I would like to see an estimate for the Noctis fogs. I just don't think this has been done yet. Also, such estimates are dependent on the phase of water that is present. If you assume thin ice crystals the amount of water will be quite low. If you assume round water droplets the amount of water will be significantly higher. I don't believe any estimate has ever been done on Mars using the assumption some proportion of the water in clouds or fogs is in liquid form.
I discussed in a different thread on this board the phenomenon of polar stratospheric clouds on Earth. These contain some liquid water aerosols down to -85 degrees C. I believe this is within the temperature range of at least low lying fogs/clouds on Mars. Note as well the sulfuric acid/nitric acid admixture in such aerosols also lowers the required pressure for liquid water to below the 6.1 mbars required for pure water.
- Bob
QUOTE (mwolff @ Jan 16 2006, 05:12 PM)
...
3) even a few pr-micron of fog (i am assuming that a fog is in the bottom scale-height of the atmosphere) would be clearly detectable by mini-TES. the detetection-limit for water-vapor is probably
in the 5-10 pr-micron region due primarily to tiny size of the lines on the longwave side and signal-to-noise issues on the shortwave side (as well as aeorsol scattering swamping any H2O radiance).
4) it is difficult to imagine that the amount of water needed to create a "mushy" morphology wouldn't
be detectable with a bound-water signature even during the day. if you have to "burn it all off" during
the day and bring it back at night, there are implications for the regional distribution of water which would make it more likely to be detected from orbit (not to mention from the rovers).
...
3) even a few pr-micron of fog (i am assuming that a fog is in the bottom scale-height of the atmosphere) would be clearly detectable by mini-TES. the detetection-limit for water-vapor is probably
in the 5-10 pr-micron region due primarily to tiny size of the lines on the longwave side and signal-to-noise issues on the shortwave side (as well as aeorsol scattering swamping any H2O radiance).
4) it is difficult to imagine that the amount of water needed to create a "mushy" morphology wouldn't
be detectable with a bound-water signature even during the day. if you have to "burn it all off" during
the day and bring it back at night, there are implications for the regional distribution of water which would make it more likely to be detected from orbit (not to mention from the rovers).
...
I don't know if fogs have been seen at the rover sites. It has been seen at the Pathfinder site. But of course fog is not required for surface deposition of water. It can condense on the surface from atmospheric water vapor.
However, I believe it is notable that both TES on Mars Global Surveyor and miniTES on the rovers detected carbonate, probably magnesium carbonate, widespread in dust on Mars. This is in low amounts in the dust, suggesting interaction of the surface material with low amounts of water.
Christensen et.al. interpret this as due to water vapor in the air:
January 09, 2004
Spirit Lowers Front Wheels, Looks Around in Infrared.
We came looking for carbonates. We have them. We're going to chase them," said Dr. Phil Christensen of Arizona State University, Tempe, leader of the Mini-TES team. Previous infrared readings from Mars orbit have revealed a low concentration of carbonates distributed globally. Christensen has interpreted that as the result of dust interaction with atmospheric water. First indications are that the carbonate concentration near Spirit may be higher than the Mars global average."
http://marsrovers.jpl.nasa.gov/newsroom/pr.../20040109a.html
But on Earth in nature carbonate is produced by iteraction with *liquid* water. There have been some laboratory experiments that attempt to show it can form with water vapor alone but this hasn't been seen in nature. I suspect in fact in these experiments some small amounts of liquid water are involved undetected by the experimenters.
It is quite key then that the HEND instrument on Mars Odyssey shows water/ice deposition occurs on Mars even at near equatorial locations:
47 - EVIDENCE OF THE SEASONAL REDISTRIBUTION OF WATER
IN THE SURFICIAL MARTIAN REGOLITH BASED ON ANALYSIS OF
THE HEND MAPPING DATA.
R.O. Kuzmin, E.V. Zabalueva, I.G. Mitrofanov,
M.L.Litvak, A.V.
Parshukov, V.Yu.Grin'kov, W. Boynton, R.S. Saunders.
"As it well seen from fig.1b,c,d, two distinctive
"hollows" of neutrons flux reduction have been appeared
in the northern hemisphere during northern summer at
Ls=130°-170° and in first half of northern winter at
Ls=270°-330°, being extended from high to low
latitudes. At that, later "hollow" (Ls=270°-330°) is
characterized by much stronger reduction of the
neutrons flux and it traces from northern polar region
up to low latitudes in the southern hemisphere. The
first "hollow" is related with periods of the northern
middle summer, while the second one - with of the
southern middle summer. In both case the residual
polar caps serve as main source of the water in the
Martian atmosphere."
p. 2
http://www.geokhi.ru/~planetology/theses/47_kuzmin_et_al.pdf
This deposition was confirmed by Opportunity by the detection of frost on the rover during the Winter season. But I consider it quite key here that HEND shows the deposition is actually higher during the current southern Summer season. So during the daytime since temperatures can exceed melting currently, the carbonate may form in the period when temperature is above melting but before it reaches the boiling point in the low atmospheric pressure on Mars.
- Bob Clark
From Space.Com - snow and glaciation on Mars:
http://www.space.com/scienceastronomy/060119_mars_snow.html
Bob Shaw
http://www.space.com/scienceastronomy/060119_mars_snow.html
Bob Shaw
I am informed that for technical reasons the rover engineers prefer not to deploy the RAT in the middle of the night. During the current Summer season, the greatest deposition probably occurs at night because of the colder temperatures. You want to cover the area during the night to preserve this water before it burns off in the daytime.
So some other methods: perhaps the RAT could be applied not in the middle of the night but close to but just before sunrise. I don't know if this would be sufficient to preserve the moisture. Another possibility: move a small rock in the middle of the night to cover a small area. Then uncover the area during the early morning, as soon as light is available.
Another possibility: it may work to use a wheel to cover the area. This would have to be done at night to insure the deposition has already occurred. Then as soon as light comes, move the vehicle to uncover the
area. The problem is this might disturb the area so much to make the moisture no longer visible.
Still another possibility: I remember reading the rover could move all the wheels so that they all dug into the ground at the same time. Then we could do that so that the bottom of the rover clung tightly to the ground. Then move the rover to uncover this area at sunrise. A problem with this is that if the rover bottom is this close to the ground it may be difficult
to extract the rover from this position.
Any others?
Bob Clark
So some other methods: perhaps the RAT could be applied not in the middle of the night but close to but just before sunrise. I don't know if this would be sufficient to preserve the moisture. Another possibility: move a small rock in the middle of the night to cover a small area. Then uncover the area during the early morning, as soon as light is available.
Another possibility: it may work to use a wheel to cover the area. This would have to be done at night to insure the deposition has already occurred. Then as soon as light comes, move the vehicle to uncover the
area. The problem is this might disturb the area so much to make the moisture no longer visible.
Still another possibility: I remember reading the rover could move all the wheels so that they all dug into the ground at the same time. Then we could do that so that the bottom of the rover clung tightly to the ground. Then move the rover to uncover this area at sunrise. A problem with this is that if the rover bottom is this close to the ground it may be difficult
to extract the rover from this position.
Any others?
Bob Clark
QUOTE (RGClark @ Jan 19 2006, 03:54 AM)
I don't know if fogs have been seen at the rover sites. It has been seen at the Pathfinder site. But of course fog is not required for surface deposition of water. It can condense on the surface from atmospheric water vapor.
However, I believe it is notable that both TES on Mars Global Surveyor and miniTES on the rovers detected carbonate, probably magnesium carbonate, widespread in dust on Mars. This is in low amounts in the dust, suggesting interaction of the surface material with low amounts of water.
Christensen et.al. interpret this as due to water vapor in the air:
January 09, 2004
Spirit Lowers Front Wheels, Looks Around in Infrared.
We came looking for carbonates. We have them. We're going to chase them," said Dr. Phil Christensen of Arizona State University, Tempe, leader of the Mini-TES team. Previous infrared readings from Mars orbit have revealed a low concentration of carbonates distributed globally. Christensen has interpreted that as the result of dust interaction with atmospheric water. First indications are that the carbonate concentration near Spirit may be higher than the Mars global average."
http://marsrovers.jpl.nasa.gov/newsroom/pr.../20040109a.html
But on Earth in nature carbonate is produced by iteraction with *liquid* water. There have been some laboratory experiments that attempt to show it can form with water vapor alone but this hasn't been seen in nature. I suspect in fact in these experiments some small amounts of liquid water are involved undetected by the experimenters.
It is quite key then that the HEND instrument on Mars Odyssey shows water/ice deposition occurs on Mars even at near equatorial locations:
47 - EVIDENCE OF THE SEASONAL REDISTRIBUTION OF WATER
IN THE SURFICIAL MARTIAN REGOLITH BASED ON ANALYSIS OF
THE HEND MAPPING DATA.
R.O. Kuzmin, E.V. Zabalueva, I.G. Mitrofanov,
M.L.Litvak, A.V.
Parshukov, V.Yu.Grin'kov, W. Boynton, R.S. Saunders.
"As it well seen from fig.1b,c,d, two distinctive
"hollows" of neutrons flux reduction have been appeared
in the northern hemisphere during northern summer at
Ls=130°-170° and in first half of northern winter at
Ls=270°-330°, being extended from high to low
latitudes. At that, later "hollow" (Ls=270°-330°) is
characterized by much stronger reduction of the
neutrons flux and it traces from northern polar region
up to low latitudes in the southern hemisphere. The
first "hollow" is related with periods of the northern
middle summer, while the second one - with of the
southern middle summer. In both case the residual
polar caps serve as main source of the water in the
Martian atmosphere."
p. 2
http://www.geokhi.ru/~planetology/theses/47_kuzmin_et_al.pdf
This deposition was confirmed by Opportunity by the detection of frost on the rover during the Winter season. But I consider it quite key here that HEND shows the deposition is actually higher during the current southern Summer season. So during the daytime since temperatures can exceed melting currently, the carbonate may form in the period when temperature is above melting but before it reaches the boiling point in the low atmospheric pressure on Mars.
- Bob Clark
However, I believe it is notable that both TES on Mars Global Surveyor and miniTES on the rovers detected carbonate, probably magnesium carbonate, widespread in dust on Mars. This is in low amounts in the dust, suggesting interaction of the surface material with low amounts of water.
Christensen et.al. interpret this as due to water vapor in the air:
January 09, 2004
Spirit Lowers Front Wheels, Looks Around in Infrared.
We came looking for carbonates. We have them. We're going to chase them," said Dr. Phil Christensen of Arizona State University, Tempe, leader of the Mini-TES team. Previous infrared readings from Mars orbit have revealed a low concentration of carbonates distributed globally. Christensen has interpreted that as the result of dust interaction with atmospheric water. First indications are that the carbonate concentration near Spirit may be higher than the Mars global average."
http://marsrovers.jpl.nasa.gov/newsroom/pr.../20040109a.html
But on Earth in nature carbonate is produced by iteraction with *liquid* water. There have been some laboratory experiments that attempt to show it can form with water vapor alone but this hasn't been seen in nature. I suspect in fact in these experiments some small amounts of liquid water are involved undetected by the experimenters.
It is quite key then that the HEND instrument on Mars Odyssey shows water/ice deposition occurs on Mars even at near equatorial locations:
47 - EVIDENCE OF THE SEASONAL REDISTRIBUTION OF WATER
IN THE SURFICIAL MARTIAN REGOLITH BASED ON ANALYSIS OF
THE HEND MAPPING DATA.
R.O. Kuzmin, E.V. Zabalueva, I.G. Mitrofanov,
M.L.Litvak, A.V.
Parshukov, V.Yu.Grin'kov, W. Boynton, R.S. Saunders.
"As it well seen from fig.1b,c,d, two distinctive
"hollows" of neutrons flux reduction have been appeared
in the northern hemisphere during northern summer at
Ls=130°-170° and in first half of northern winter at
Ls=270°-330°, being extended from high to low
latitudes. At that, later "hollow" (Ls=270°-330°) is
characterized by much stronger reduction of the
neutrons flux and it traces from northern polar region
up to low latitudes in the southern hemisphere. The
first "hollow" is related with periods of the northern
middle summer, while the second one - with of the
southern middle summer. In both case the residual
polar caps serve as main source of the water in the
Martian atmosphere."
p. 2
http://www.geokhi.ru/~planetology/theses/47_kuzmin_et_al.pdf
This deposition was confirmed by Opportunity by the detection of frost on the rover during the Winter season. But I consider it quite key here that HEND shows the deposition is actually higher during the current southern Summer season. So during the daytime since temperatures can exceed melting currently, the carbonate may form in the period when temperature is above melting but before it reaches the boiling point in the low atmospheric pressure on Mars.
- Bob Clark
Bob:
I think we *do* have circumstantial evidence for damp soils already, in the form of the flowing surface materials spotted at several points by Spirit, and recently by Opportunity. These may have other explanations, but to my mind some form of material plasticity is the simplest - and water is the obvious plasticiser!
As for digging a rover in, and settling down on the dirt - er, no, please, please don't let them do that. Purgatory Dune was bad enough as an accident, but to do it on purpose...
Bob Shaw
I think we *do* have circumstantial evidence for damp soils already, in the form of the flowing surface materials spotted at several points by Spirit, and recently by Opportunity. These may have other explanations, but to my mind some form of material plasticity is the simplest - and water is the obvious plasticiser!
As for digging a rover in, and settling down on the dirt - er, no, please, please don't let them do that. Purgatory Dune was bad enough as an accident, but to do it on purpose...
Bob Shaw
The following reports to be presented to the 2006 Lunar and Planetary Science Conference discuss seasonal variations in the bound water content even at near equatorial latitudes:
SPATIAL AND TEMPORAL VARIATIONS OF BOUND WATER CONTENT IN THE MARTIAN SOIL WITHIN THE GUSEV CRATER: PRELIMINARY RESULTS OF THE TES AND MINI-TES DATA ANALYSIS.
R. O. Kuzmin1, P. R. Christensen2, S. W. Ruff2, T. G. Graff2, A. T. Knudson2, M. Yu. Zolotov2, Athena Science Team, 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, USA.
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1673.pdf
MAPPING OF SEASONAL BOUND WATER CONTENT VARIATIONS ON THE MARTIAN SURFACE BASED ON THE TES DATA.
R. O. Kuzmin1, P. R. Christensen2, M. Yu. Zolotov2 and S. Anwar2. 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.
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1846.pdf
This confirms observations of the HEND instrument on Mars Odyssey of seasonal variations in the deposited water/ice content of the soil. Note that this strongly implies the varying bound water is due to this seasonal water deposition.
One type of mineral found containing the bound water is carbonate. Then this carbonate should arise from this seasonal deposition. Most importantly this implies this carbonate is currently forming.
One small discrepancy in the bound water observations and the HEND measurements is that HEND suggests that in the south, the greatest deposition occurs in the southern Summer, while the bound water measurements show the largest amount of bound water is observed in the southern Winter.
A possible explanation is based on the idea that the currently forming bound water minerals are formed from liquid water brines. Since these latitudes are near the equator, mid-day temperatures could be within the range of liquid water brines even during Winter.
However, the Summer daytime temperatures may be too high to permit the water to remain liquid for long before evaporating.
Evidence for this is that during southern Summer, clouds have been seen by the Opportunity rover at night when the temperatures are low, while the clouds and frosts have not been seen during the day. Since similar clouds corresponded to observed frost deposition on the Opportunity rover during the southern Winter, it is very likely water/ice deposition occurred during the southern Summer as well, though at night when the clouds appear.
I want to suggest that a search be made for this night-time deposition by methods such as described in the post to sci.astro below.
Note experiments in simulated Mars conditions show that water can stay liquid in brines for short times on Mars:
Water just might stay liquid on Mars
Studies show salty water can persist, raising hopes for life.
http://msnbc.msn.com/id/10052714/from/RL.2/
For this reason it very likely the currently forming carbonate on Mars is formed from liquid water as it is on Earth.
Bob Clark
===========================================================
From: Robert Clark
Date: Thurs, Jan 19 2006 12:15 pm
Email: "Robert Clark" <rgregorycl...@yahoo.com>
Groups: sci.astro, alt.sci.planetary, sci.physics
Subject: Re: Could We Make A "Solar Still" On Mars?
There have been some video posted to the Unmannedspaceflight.com site
of these night-time clouds:
http://media.putfile.com/earthrise-oppy-sol-687
http://www.lyle.org/~markoff/op_movie/opp_687L1.gif
Do the fast bright streaks in the second video look like meteorite
trails?
I suggested the current deposition of the water/ice at Meridiani may
become liquid at some point because of the warm maximum temperatures
during the current Summer season. This is supported by the detection of
carbonate in dust by the rovers, and also from orbit:
January 09, 2004
Spirit Lowers Front Wheels, Looks Around in Infrared.
"We came looking for carbonates. We have them. We're going to chase
them," said Dr. Phil Christensen of Arizona State University, Tempe,
leader of the Mini-TES team. Previous infrared readings from Mars orbit
have revealed a low concentration of carbonates distributed globally.
Christensen has interpreted that as the result of dust interaction with
atmospheric water. First indications are that the carbonate
concentration near Spirit may be higher than the Mars global average."
http://marsrovers.jpl.nasa.gov/newsroom/pr.../20040109a.html
On Earth in nature carbonate is produced by iteraction with *liquid*
water. There have been some laboratory experiments that attempt to show
it can form with water vapor alone but this hasn't been seen in nature.
I suspect in fact in these experiments some small amounts of liquid
water are involved undetected by the experimenters.
It is quite key then that the HEND instrument on Mars Odyssey shows
water/ice deposition occurs on Mars even at near equatorial locations:
47 - EVIDENCE OF THE SEASONAL REDISTRIBUTION OF WATER
IN THE SURFICIAL MARTIAN REGOLITH BASED ON ANALYSIS OF
THE HEND MAPPING DATA.
R.O. Kuzmin, E.V. Zabalueva, I.G. Mitrofanov,
M.L.Litvak, A.V.
Parshukov, V.Yu.Grin'kov, W. Boynton, R.S. Saunders.
"As it well seen from fig.1b,c,d, two distinctive
"hollows" of neutrons flux reduction have been appeared
in the northern hemisphere during northern summer at
Ls=130°-170° and in first half of northern winter at
Ls=270°-330°, being extended from high to low
latitudes. At that, later "hollow" (Ls=270°-330°) is
characterized by much stronger reduction of the
neutrons flux and it traces from northern polar region
up to low latitudes in the southern hemisphere. The
first "hollow" is related with periods of the northern
middle summer, while the second one - with of the
southern middle summer. In both case the residual
polar caps serve as main source of the water in the
Martian atmosphere."
p. 2
http://www.geokhi.ru/~planetology/theses/47_kuzmin_et_al.pdf
This deposition was confirmed by Opportunity by the detection of frost
on the rover during the Winter season. But I consider it quite key here
that HEND shows the deposition is actually higher during the current
southern Summer season. So since maximal temperatures can exceed
melting currently, the carbonate may form in the period when
temperature is above melting but before it reaches the boiling point in
the low atmospheric pressure on Mars.
I therefore propose to search for this liquid water by the rovers.
However, I am informed that for technical reasons the rover engineers
prefer not to deploy the rover arm in the middle of the night. During
the current Summer season, the greatest deposition probably occurs at
night because of the colder temperatures. You want to cover the area
during the night to preserve this water before it burns off in the
daytime.
So some other methods: perhaps the RAT could be applied not in the
middle of the night but close to but just before sunrise. I don't know
if this would be sufficient to preserve the moisture. Another
possibility: move a small rock in the middle of the night to cover a
small area. Then uncover the area during the early morning, as soon as
light is available.
Another possibility: it may work to use a wheel to cover the area. This
would have to be done at night to insure the deposition has already
occurred. Then as soon as light comes, move the vehicle to uncover the
area. The problem is this might disturb the area so much to make the
moisture no longer visible.
Still another possibility: I remember reading the rover could move all
the wheels so that they all dug into the ground at the same time. Then
we could do that so that the bottom of the rover clung tightly to the
ground. Then move the rover to uncover this area at sunrise. A problem
with this is that if the rover bottom is this close to the ground it
may be difficult
to extract the rover from this position.
Any others?
Bob Clark
Robert Clark wrote:
> Note we might already be seeing an example of this. See the MI images
> here:
> Erebus Outcrops.
> http://www.markcarey.com/cgi-bin/mt/mt-vie.../27390/discus...
> The flattened areas have a mushy appearance to them. Another check for
> this might be to perform a RAT observation early in the morning where
> there might be residual moisture left and compare this to a RAT
> observation of a spot nearby later in the afternoon when moisture would
> be expected to burn off.
> Would there be a difference in the appearance in the two RATted areas?
> Bob Clark
> Robert Clark wrote:
> > Mars Odyssey hydrogen-content measurements have shown seasonal
> > deposition of water/ice on Mars even at equatorial locations. This has
> > been confirmed by the Opportunity rover in Meridiani by the observation
> > of early morning frost on the rover:
> > More on "Frost on the rover solar panels".
> > http://bautforum.com/showpost.php?p=323577&postcount=6
> > This deposition of frost at Meridiani corresponded to the observation
> > of clouds over the site during the local Winter:
> > Mars Rovers Spot Water-Clue Mineral, Frost, Clouds.
> > 13-Dec-2004
> > http://marsrovers.jpl.nasa.gov/gallery/pre.../20041213a.html
> > Since clouds have also been seen over the site during the current
> > Summer season, I argue this should also correspond to water/ice
> > deposition currently at the Meridiani landing site:
> > Space Sciences
> > Summer clouds over Meridiani?
> > Posted by Robert Clark on 12/31/2005 6:56:40 PM
> > http://habitablezone.com/space/messages/409185.html
> > The "Mars Rovers Spot Water-Clue Mineral, Frost, Clouds" press release
> > showed the frost forming in early morning in the Winter season. The
> > image of the frost was taken 11 minutes after sunrise, and a subsequent
> > image showed the frost had burned off 3 hours later due to rising
> > temperatures.
> > Perhaps the clouds in the images in the current season appear at night
> > because of the coldness at night during this current Summer period.
> > Then we might expect the greatest water/ice deposition to also occur at
> > night.
> > Could the mini-TES detect H2O on the rover at night? Could we for
> > example compare the spectra at night to the morning spectra?
> > Another experiment I suggest to try would be to press down with the RAT
> > at night and keep the area covered till early morning. Then uncover the
> > area soon after sunrise to see if there are any remaining signs of
> > moisture.
> > This may have what occurred at the Gusev landing site with the Spirit
> > rover landing bags with the observation of the "magic carpet" mud-like
> > material. The Gusev landing occurred within the period that the Mars
> > Odyssey readings showed the greatest water/ice deposition occurs during
> > southern Summer. Then the landing bags covering the soil may have
> > allowed deposited water/ice to be retained against
> > sublimation/evaporation. When the bags were pulled away, moist soil
> > would have been revealed.
> > That this deposition occurs may provide a means of obtaining water for
> > consumption or fuel (hydrogen through electrolysis) by future manned
> > missions. The method of a "solar still" allows water vapor in the air
> > to be collected and condensed to liquid water even in desert regions:
> > Desert Survival
> > Collect Water in a Solar Still.
> > http://www.desertusa.com/mag98/dec/stories/water.html
> > Bob Clark
==============================================================
SPATIAL AND TEMPORAL VARIATIONS OF BOUND WATER CONTENT IN THE MARTIAN SOIL WITHIN THE GUSEV CRATER: PRELIMINARY RESULTS OF THE TES AND MINI-TES DATA ANALYSIS.
R. O. Kuzmin1, P. R. Christensen2, S. W. Ruff2, T. G. Graff2, A. T. Knudson2, M. Yu. Zolotov2, Athena Science Team, 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, USA.
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1673.pdf
MAPPING OF SEASONAL BOUND WATER CONTENT VARIATIONS ON THE MARTIAN SURFACE BASED ON THE TES DATA.
R. O. Kuzmin1, P. R. Christensen2, M. Yu. Zolotov2 and S. Anwar2. 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.
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1846.pdf
This confirms observations of the HEND instrument on Mars Odyssey of seasonal variations in the deposited water/ice content of the soil. Note that this strongly implies the varying bound water is due to this seasonal water deposition.
One type of mineral found containing the bound water is carbonate. Then this carbonate should arise from this seasonal deposition. Most importantly this implies this carbonate is currently forming.
One small discrepancy in the bound water observations and the HEND measurements is that HEND suggests that in the south, the greatest deposition occurs in the southern Summer, while the bound water measurements show the largest amount of bound water is observed in the southern Winter.
A possible explanation is based on the idea that the currently forming bound water minerals are formed from liquid water brines. Since these latitudes are near the equator, mid-day temperatures could be within the range of liquid water brines even during Winter.
However, the Summer daytime temperatures may be too high to permit the water to remain liquid for long before evaporating.
Evidence for this is that during southern Summer, clouds have been seen by the Opportunity rover at night when the temperatures are low, while the clouds and frosts have not been seen during the day. Since similar clouds corresponded to observed frost deposition on the Opportunity rover during the southern Winter, it is very likely water/ice deposition occurred during the southern Summer as well, though at night when the clouds appear.
I want to suggest that a search be made for this night-time deposition by methods such as described in the post to sci.astro below.
Note experiments in simulated Mars conditions show that water can stay liquid in brines for short times on Mars:
Water just might stay liquid on Mars
Studies show salty water can persist, raising hopes for life.
http://msnbc.msn.com/id/10052714/from/RL.2/
For this reason it very likely the currently forming carbonate on Mars is formed from liquid water as it is on Earth.
Bob Clark
===========================================================
From: Robert Clark
Date: Thurs, Jan 19 2006 12:15 pm
Email: "Robert Clark" <rgregorycl...@yahoo.com>
Groups: sci.astro, alt.sci.planetary, sci.physics
Subject: Re: Could We Make A "Solar Still" On Mars?
There have been some video posted to the Unmannedspaceflight.com site
of these night-time clouds:
http://media.putfile.com/earthrise-oppy-sol-687
http://www.lyle.org/~markoff/op_movie/opp_687L1.gif
Do the fast bright streaks in the second video look like meteorite
trails?
I suggested the current deposition of the water/ice at Meridiani may
become liquid at some point because of the warm maximum temperatures
during the current Summer season. This is supported by the detection of
carbonate in dust by the rovers, and also from orbit:
January 09, 2004
Spirit Lowers Front Wheels, Looks Around in Infrared.
"We came looking for carbonates. We have them. We're going to chase
them," said Dr. Phil Christensen of Arizona State University, Tempe,
leader of the Mini-TES team. Previous infrared readings from Mars orbit
have revealed a low concentration of carbonates distributed globally.
Christensen has interpreted that as the result of dust interaction with
atmospheric water. First indications are that the carbonate
concentration near Spirit may be higher than the Mars global average."
http://marsrovers.jpl.nasa.gov/newsroom/pr.../20040109a.html
On Earth in nature carbonate is produced by iteraction with *liquid*
water. There have been some laboratory experiments that attempt to show
it can form with water vapor alone but this hasn't been seen in nature.
I suspect in fact in these experiments some small amounts of liquid
water are involved undetected by the experimenters.
It is quite key then that the HEND instrument on Mars Odyssey shows
water/ice deposition occurs on Mars even at near equatorial locations:
47 - EVIDENCE OF THE SEASONAL REDISTRIBUTION OF WATER
IN THE SURFICIAL MARTIAN REGOLITH BASED ON ANALYSIS OF
THE HEND MAPPING DATA.
R.O. Kuzmin, E.V. Zabalueva, I.G. Mitrofanov,
M.L.Litvak, A.V.
Parshukov, V.Yu.Grin'kov, W. Boynton, R.S. Saunders.
"As it well seen from fig.1b,c,d, two distinctive
"hollows" of neutrons flux reduction have been appeared
in the northern hemisphere during northern summer at
Ls=130°-170° and in first half of northern winter at
Ls=270°-330°, being extended from high to low
latitudes. At that, later "hollow" (Ls=270°-330°) is
characterized by much stronger reduction of the
neutrons flux and it traces from northern polar region
up to low latitudes in the southern hemisphere. The
first "hollow" is related with periods of the northern
middle summer, while the second one - with of the
southern middle summer. In both case the residual
polar caps serve as main source of the water in the
Martian atmosphere."
p. 2
http://www.geokhi.ru/~planetology/theses/47_kuzmin_et_al.pdf
This deposition was confirmed by Opportunity by the detection of frost
on the rover during the Winter season. But I consider it quite key here
that HEND shows the deposition is actually higher during the current
southern Summer season. So since maximal temperatures can exceed
melting currently, the carbonate may form in the period when
temperature is above melting but before it reaches the boiling point in
the low atmospheric pressure on Mars.
I therefore propose to search for this liquid water by the rovers.
However, I am informed that for technical reasons the rover engineers
prefer not to deploy the rover arm in the middle of the night. During
the current Summer season, the greatest deposition probably occurs at
night because of the colder temperatures. You want to cover the area
during the night to preserve this water before it burns off in the
daytime.
So some other methods: perhaps the RAT could be applied not in the
middle of the night but close to but just before sunrise. I don't know
if this would be sufficient to preserve the moisture. Another
possibility: move a small rock in the middle of the night to cover a
small area. Then uncover the area during the early morning, as soon as
light is available.
Another possibility: it may work to use a wheel to cover the area. This
would have to be done at night to insure the deposition has already
occurred. Then as soon as light comes, move the vehicle to uncover the
area. The problem is this might disturb the area so much to make the
moisture no longer visible.
Still another possibility: I remember reading the rover could move all
the wheels so that they all dug into the ground at the same time. Then
we could do that so that the bottom of the rover clung tightly to the
ground. Then move the rover to uncover this area at sunrise. A problem
with this is that if the rover bottom is this close to the ground it
may be difficult
to extract the rover from this position.
Any others?
Bob Clark
Robert Clark wrote:
> Note we might already be seeing an example of this. See the MI images
> here:
> Erebus Outcrops.
> http://www.markcarey.com/cgi-bin/mt/mt-vie.../27390/discus...
> The flattened areas have a mushy appearance to them. Another check for
> this might be to perform a RAT observation early in the morning where
> there might be residual moisture left and compare this to a RAT
> observation of a spot nearby later in the afternoon when moisture would
> be expected to burn off.
> Would there be a difference in the appearance in the two RATted areas?
> Bob Clark
> Robert Clark wrote:
> > Mars Odyssey hydrogen-content measurements have shown seasonal
> > deposition of water/ice on Mars even at equatorial locations. This has
> > been confirmed by the Opportunity rover in Meridiani by the observation
> > of early morning frost on the rover:
> > More on "Frost on the rover solar panels".
> > http://bautforum.com/showpost.php?p=323577&postcount=6
> > This deposition of frost at Meridiani corresponded to the observation
> > of clouds over the site during the local Winter:
> > Mars Rovers Spot Water-Clue Mineral, Frost, Clouds.
> > 13-Dec-2004
> > http://marsrovers.jpl.nasa.gov/gallery/pre.../20041213a.html
> > Since clouds have also been seen over the site during the current
> > Summer season, I argue this should also correspond to water/ice
> > deposition currently at the Meridiani landing site:
> > Space Sciences
> > Summer clouds over Meridiani?
> > Posted by Robert Clark on 12/31/2005 6:56:40 PM
> > http://habitablezone.com/space/messages/409185.html
> > The "Mars Rovers Spot Water-Clue Mineral, Frost, Clouds" press release
> > showed the frost forming in early morning in the Winter season. The
> > image of the frost was taken 11 minutes after sunrise, and a subsequent
> > image showed the frost had burned off 3 hours later due to rising
> > temperatures.
> > Perhaps the clouds in the images in the current season appear at night
> > because of the coldness at night during this current Summer period.
> > Then we might expect the greatest water/ice deposition to also occur at
> > night.
> > Could the mini-TES detect H2O on the rover at night? Could we for
> > example compare the spectra at night to the morning spectra?
> > Another experiment I suggest to try would be to press down with the RAT
> > at night and keep the area covered till early morning. Then uncover the
> > area soon after sunrise to see if there are any remaining signs of
> > moisture.
> > This may have what occurred at the Gusev landing site with the Spirit
> > rover landing bags with the observation of the "magic carpet" mud-like
> > material. The Gusev landing occurred within the period that the Mars
> > Odyssey readings showed the greatest water/ice deposition occurs during
> > southern Summer. Then the landing bags covering the soil may have
> > allowed deposited water/ice to be retained against
> > sublimation/evaporation. When the bags were pulled away, moist soil
> > would have been revealed.
> > That this deposition occurs may provide a means of obtaining water for
> > consumption or fuel (hydrogen through electrolysis) by future manned
> > missions. The method of a "solar still" allows water vapor in the air
> > to be collected and condensed to liquid water even in desert regions:
> > Desert Survival
> > Collect Water in a Solar Still.
> > http://www.desertusa.com/mag98/dec/stories/water.html
> > Bob Clark
==============================================================
The mini-TES on the rovers has confirmed what was seen from orbit with TES that carbonate exists in small amounts in dust widespread on Mars:
January 09, 2004
Spirit Lowers Front Wheels, Looks Around in Infrared.
"We came looking for carbonates. We have them. We're going to chase
them," said Dr. Phil Christensen of Arizona State University, Tempe,
leader of the Mini-TES team. Previous infrared readings from Mars orbit
have revealed a low concentration of carbonates distributed globally.
Christensen has interpreted that as the result of dust interaction with
atmospheric water. First indications are that the carbonate
concentration near Spirit may be higher than the Mars global average."
http://marsrovers.jpl.nasa.gov/newsroom/pr.../20040109a.html
These new readings show these amounts are seasonal. This coincides with the HEND Mars Odyssey measurements showing low amounts of water deposition occurring seasonally, and even at near equatorial latitudes.
Note also the MI imager on the rover shows "cementation" of the dust into crusts:
OVERVIEW OF ATHENA MICROSCOPIC IMAGER RESULTS.
K. Herkenhoff1 (****@usgs.gov), S. Squyres2, R. Arvidson3, J. Bell III2, N. Cabrol4, M. Chapman1, B. Ehlmann3, B. Franklin5, L. Gaddis1, P. Geissler1, R. Greeley6, J. Grotzinger5, J. Johnson1, B. Jolliff3, L. Keszthelyi1, A. Knoll7, P. Lanagan8, E. Lee1, J. Maki5, S. McLennan9, D. Ming10, K. Mullins1, J. Rice6, L. Richter11, M. Sims4, L. Soderblom1, N. Spanovich5, R.
Springer5, R. Sucharski1, R. Sullivan2, C. Weitz12, and the Athena Science Team, 1U. S. Geological Survey, Flagstaff, AZ 86001; 2Cornell Univ.; 3Washington Univ.; 4NASA Ames Research Center; 5Caltech/JPL; 6ASU; 7Harvard Univ.; 8Univ. Arizona; 9SUNY, Stony Brook; 10NASA JSC; 11DLR Institut fur Raumsimulation; 12PSI.
Lunar and Planetary Science XXXVII (2006) 1816.pdf
"Some MI observations of soils
disturbed by the MB contact plate show apparent
fractures, suggesting that cementation of surface
particles has formed a crust. The thickness of this
crust is estimated to be at least 1 mm (the penetration
depth of the MB contact plate) based upon images
taken after the surface was disrupted. Plausibly, and
consistent with APXS spectra of soil-like deposits at
the Meridiani site, the cementation is caused by
precipitation of various salts (e.g., Cl- and SO4-
bearing) that bridge soil particles. Salts in the dust
(unresolved by the MI) may dissolve and migrate into
voids between soil particles in thin films of water
adsorbed onto soil particles. Thin liquid films may
occur in soils when the spin axis obliquity and
atmospheric relative humidity are high enough to
cause precipitation or condensation of water. During
warming events, salts may precipitate on soil
particles as thin liquid films evaporate, weakly
cementing the upper soil surface."
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1816.pdf
This was speaking of the MI images at Opportunity:
Opportunity :: Microscopic Imager :: Sol 050.
However, such cementation crusts have now been seen by Spirit at the "Home Plate" formation:
Spirit :: Microscopic Imager :: Sol 747.
The report spoke of the liquid water films occurring during high obliquity periods. But the Mars Odyssey HEND data shows water/ice deposition is occurring now seasonally at these sites. Since now both theoretical calculations and actual experiment show liquid water can exist on Mars for short periods, the evidence is now overwhelming that current liquid water, perhaps only as thin briny films, is the origin both of currently forming carbonate dust and of currently forming cementation crusts and these are very likely widespread on Mars.
Bob Clark
January 09, 2004
Spirit Lowers Front Wheels, Looks Around in Infrared.
"We came looking for carbonates. We have them. We're going to chase
them," said Dr. Phil Christensen of Arizona State University, Tempe,
leader of the Mini-TES team. Previous infrared readings from Mars orbit
have revealed a low concentration of carbonates distributed globally.
Christensen has interpreted that as the result of dust interaction with
atmospheric water. First indications are that the carbonate
concentration near Spirit may be higher than the Mars global average."
http://marsrovers.jpl.nasa.gov/newsroom/pr.../20040109a.html
These new readings show these amounts are seasonal. This coincides with the HEND Mars Odyssey measurements showing low amounts of water deposition occurring seasonally, and even at near equatorial latitudes.
Note also the MI imager on the rover shows "cementation" of the dust into crusts:
OVERVIEW OF ATHENA MICROSCOPIC IMAGER RESULTS.
K. Herkenhoff1 (****@usgs.gov), S. Squyres2, R. Arvidson3, J. Bell III2, N. Cabrol4, M. Chapman1, B. Ehlmann3, B. Franklin5, L. Gaddis1, P. Geissler1, R. Greeley6, J. Grotzinger5, J. Johnson1, B. Jolliff3, L. Keszthelyi1, A. Knoll7, P. Lanagan8, E. Lee1, J. Maki5, S. McLennan9, D. Ming10, K. Mullins1, J. Rice6, L. Richter11, M. Sims4, L. Soderblom1, N. Spanovich5, R.
Springer5, R. Sucharski1, R. Sullivan2, C. Weitz12, and the Athena Science Team, 1U. S. Geological Survey, Flagstaff, AZ 86001; 2Cornell Univ.; 3Washington Univ.; 4NASA Ames Research Center; 5Caltech/JPL; 6ASU; 7Harvard Univ.; 8Univ. Arizona; 9SUNY, Stony Brook; 10NASA JSC; 11DLR Institut fur Raumsimulation; 12PSI.
Lunar and Planetary Science XXXVII (2006) 1816.pdf
"Some MI observations of soils
disturbed by the MB contact plate show apparent
fractures, suggesting that cementation of surface
particles has formed a crust. The thickness of this
crust is estimated to be at least 1 mm (the penetration
depth of the MB contact plate) based upon images
taken after the surface was disrupted. Plausibly, and
consistent with APXS spectra of soil-like deposits at
the Meridiani site, the cementation is caused by
precipitation of various salts (e.g., Cl- and SO4-
bearing) that bridge soil particles. Salts in the dust
(unresolved by the MI) may dissolve and migrate into
voids between soil particles in thin films of water
adsorbed onto soil particles. Thin liquid films may
occur in soils when the spin axis obliquity and
atmospheric relative humidity are high enough to
cause precipitation or condensation of water. During
warming events, salts may precipitate on soil
particles as thin liquid films evaporate, weakly
cementing the upper soil surface."
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1816.pdf
This was speaking of the MI images at Opportunity:
Opportunity :: Microscopic Imager :: Sol 050.
However, such cementation crusts have now been seen by Spirit at the "Home Plate" formation:
Spirit :: Microscopic Imager :: Sol 747.
The report spoke of the liquid water films occurring during high obliquity periods. But the Mars Odyssey HEND data shows water/ice deposition is occurring now seasonally at these sites. Since now both theoretical calculations and actual experiment show liquid water can exist on Mars for short periods, the evidence is now overwhelming that current liquid water, perhaps only as thin briny films, is the origin both of currently forming carbonate dust and of currently forming cementation crusts and these are very likely widespread on Mars.
Bob Clark
The OMEGA infrared instrument on Mars Express has also observed a seasonal variation in hydration on the Martian surface:
OBSERVATION OF 3 mu-m HYDRATION FEATURE ON MARS FROM OMEGA-MEx DATA.
D. Jouglet1, F. Poulet1, J. Mustard2, R. Milliken2, J.P. Bibring1, Y. Langevin1, B. Gondet1 and the OMEGA team.
1IAS, Université Paris 11, 91405 Orsay Cedex, France, ****@ias.u-psud.fr. 2Brown University,
Providence, USA.
Lunar and Planetary Science XXXVII (2006) 1741.pdf
"The temporal evolution of soil hydration is
therefore not due to an instrumental effect. We have
checked on TES results from 1999 to 2004 [10] that dust
opacity and water-ice opacity are constant between the
two observations. This suggests that the temporal
evolution is not due to aerosols in atmosphere. We may
explain it by the presence of water frost during winter,
shown by OMEGA observations [1]. The winter frost has
probably enriched the hydration of minerals as seen at
the beginning of spring (after the end of the frost
sublimation). During all spring and during the beginning
of summer, the surface goes back to equilibrium with the
atmosphere, decreasing its hydration as seen at the
beginning of summer."
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1741.pdf
This variation though was observed at high latitudes 40N to 60N. They also apparently believe this observed variation can be explained simply by surface deposited water.
Bob Clark
OBSERVATION OF 3 mu-m HYDRATION FEATURE ON MARS FROM OMEGA-MEx DATA.
D. Jouglet1, F. Poulet1, J. Mustard2, R. Milliken2, J.P. Bibring1, Y. Langevin1, B. Gondet1 and the OMEGA team.
1IAS, Université Paris 11, 91405 Orsay Cedex, France, ****@ias.u-psud.fr. 2Brown University,
Providence, USA.
Lunar and Planetary Science XXXVII (2006) 1741.pdf
"The temporal evolution of soil hydration is
therefore not due to an instrumental effect. We have
checked on TES results from 1999 to 2004 [10] that dust
opacity and water-ice opacity are constant between the
two observations. This suggests that the temporal
evolution is not due to aerosols in atmosphere. We may
explain it by the presence of water frost during winter,
shown by OMEGA observations [1]. The winter frost has
probably enriched the hydration of minerals as seen at
the beginning of spring (after the end of the frost
sublimation). During all spring and during the beginning
of summer, the surface goes back to equilibrium with the
atmosphere, decreasing its hydration as seen at the
beginning of summer."
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1741.pdf
This variation though was observed at high latitudes 40N to 60N. They also apparently believe this observed variation can be explained simply by surface deposited water.
Bob Clark
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