Martian Soil Study - the dirt on the dirt

Having viewed most of the mars lander photo's, I started to do some thinking on the landscape.

It all just looks too neat.

1- The soil seems to exibit some cohesiveness. Kinda like wet snow. The marks left by the rover and craft bags, have left imprints on the soil that demonstrate this. Going on the assumption that water is not commonly on the surface, it seems to imply that some other liquid or condensation is prevolent. Notice the shimmer or glisten that some of the rocks seem to show.


2- The rocks are scattered fairly evenly and are commonly of the same size, with the occasional large rocks here and there. I have noticed that some of the rocks, have mating parts that appear to have just fallen off the 'parent' rock, and fallen to the side without the appearance of force or impact anywhere. This I find really interesting, as it would demonstrate some non-violent natural occuring fragmentation process.

3- The rover wheel tracks as well as the impression the bags left in the soil, have shown that little force is required to impact the rocks into the soil. This tells me that the surface soil is soft, or chemically 'wet'.

4- The wind patterns left in the surface photo's suggest that the prevailing winds are constant when blowing and mono-directional. The soil does blow away, as can be seen by the wind tracks, soil piles (mini-dunes), and if you look at an undisturbed rock, the soil leaves a wash pattern that shows the deposits and clear areas consistantly all around.

5- Finally, many of the larger rocks appear to have two hues. Light on one side, dark on the other. (excluding shadows). If these were meteor fragments I suppose that the content of these rocks could be of metalic nature, such as nickel, that has oxidized on one side. This can be noticed similarly by the surrounding rocks, on the same sides.




So why all the rocks scattered on top of the soil in an even distribution? Many of them appear to be scattered from some force. Many of them appear sharp and jagged, and yet few seem smooth and wind-worn or sand blasted.

It occurs to me that this could be caused by a shallow soil layer, with a firmer surface below supporting the rocks. Over mellenia the winds should have buried the rocks, as the weight of them would bring them below as the lighter sands blew around, and away, and back again.



Or the content of the soil is of such that it is Heavier than the rocks, technically 'floating' the rocks on the surface.




Some observations I had....thoughts?

..

i love physical geography

You said the rocks could have oxidized...doesnt that require oxygen?

another question is do we know of a gas that can exist in a liquid state at the temperatures found on mars?

Originally posted by cyberpilot
You said the rocks could have oxidized...doesnt that require oxygen?

another question is do we know of a gas that can exist in a liquid state at the temperatures found on mars?

I suggested that if the rocks were of meteors, they could have a high metalic content, possibly nickel or such, and some metals when oxidized, turn black or other dark colors.

I know that many gas elements, liquid elemets, as well as chemical compounds can change state in many different temperature ranges, and with the temperature swings that may occur on mars from night to day, it is conceivable that some liquids may turn to a gas, or condense to a liquid as the temperatures change with the sun exposure. Additionally, without any cloud cover the sun and it's warming radiation and light, may help to advance the warming, or cooling at dusk.

Originally posted by cyberpilot
You said the rocks could have oxidized...doesnt that require oxygen?

another question is do we know of a gas that can exist in a liquid state at the temperatures found on mars?

wars was like earth eons ago but sonething happened that locked the oxygen in the rocks and soil

They are more than rocks depending on what you want to believe.

Originally posted by smirkley

I suggested that if the rocks were of meteors, they could have a high metalic content, possibly nickel or such, and some metals when oxidized, turn black or other dark colors.

yes I understand this...but what is the source of oxygen for the oxidization to occur?

Smirkley, in response to your first observation, check out this article Did Spirit Land in Mud

They are more than rocks depending on what you want to believe.

I must admit some of the pictures were interesting but hardly "proof" of anything

It may have been colored in but one did kinda look like alge

Thanks for the link WOS...

I wish I had seen that earlier I would have included it.
(I was just reflecting observations of interest)


A new thought....if it is a very consentrated Brine, then it could also be implied that the Spirit's intermitten problems could possibly be caused by advanced corrosive contamination from the salts, getting into the systems.

This might be applied to all the other failed missions also.


Also,...if it is a high consentrate brine,...then maybe the soil is heavier than the rocks, and the rocks are 'floating' on the surface.

Like swimming in the dead sea.

[Edited on 25-1-2004 by smirkley]

"They are more than rocks depending on what you want to believe."

www.enterprisemission.com...

I'd just like to point out they missed out one along the first set of "artifact" images...




[Edited on 25-1-2004 by GeniusSage]

Another point, if there is alot of salt in the soil, it might explain the unusual cohesive properties of the grains noticed at the Spirit landing site.



[Edited on 1-25-2004 by William One Sac]

It seems that salt, brine, and mud, can provide logical reasoning for many of the anomolies of the martian soil, and possibly explanation for all the mission failures and difficulties.


Salt would be a good way to trap moisture in the soil, but would also make the soil a poor medium for supporting any plant growth.

[Edited on 25-1-2004 by smirkley]

Mud? So that means there would need to be water on the surface.

Ignore the glaciers and the landscape in the Antarctic dry valleys looks very similer to Mars

ucsdnews.ucsd.edu...

but I can't get the image to resize. so just click on it for a link



[Edited on 25-1-2004 by HowardRoark]

[Edited on 25-1-2004 by HowardRoark]

[Edited on 25-1-2004 by HowardRoark]

[Edited on 25-1-2004 by HowardRoark]

[Edited on 27-1-2004 by HowardRoark]

mmm interesting. Well first of all wouldn't the rocks be polished by the fine sand? that might effect the "shine". Maybe the color (lighter/darker side) couls be caused by the sun bleaching it? *doesn't know much about rocks* *feels stupid* Um.....

marsrovers.jpl.nasa.gov...

I have given a bit more thought on the 'split' rocks in some of the images.


Without cloud cover the radiation energy, heat and otherwise would be directly applied to the rocks during daytime.

As the sun set and the cool of night began to saturate the air, the rock would maintain a higher core temperature than the outside surface of the rock. Soon the cool would begin to transmit to the outer crust of the rocks, and gradually move inward as the heat inside would begin to dissapate.

The temperature differential, day after day, morning and night, may be enough to split the rock, like dropping hot glass in cold water.

Just found a bit with discussion (pdf) about...dirt.



The following PDF goes in to detail about the subject of SOIL CEMENTING,
and does discuss the cementing process when considered with ;
low pressure atmosphere, salt content binding of particles, and soil moisture content

all helping to CEMENT the soil in a fashion that would give it unusual cohesive properties,
and seemingly help to violate STOKES LAW, as described below.

ESTIMATION OF SOIL THERMAL CONDUCTIVITY FROM A MARS MICROPROBETYPE


Additional information on soil properties as shown below.

Soil Physical Properties


Soil mineralogical composition:
� Primary minerals: present in original rock from which soil is formed. These occur
predominantly in sand and silt fractions, and are weathering resistant (quartz,
feldspars);
� Secondary minerals: formed by decomposition of primary minerals, and their
subsequent weathering and recomposition into new ones (clay minerals).
� Humus or organic matter (decomposed organic materials)

Mineral type has large influence on soil behavior:
� Ion exchange, related to cation exchange capacity
� Hydration and swelling; dehydration and shrinking
� Flocculation and dispersion
� Preferential flow, as through soil cracks
� Barrier to flow, as by swelling clays
� Chemical adsorption of contaminants and nutrients, both in liquid and gas phase




Some information suggesting what was implied above,
in reference to the scatterred rocks
that seem to perpetuate on the surface.
This has to do with the appearance on the new mars images of
many rocks that seme to 'float' on the surface undisturbed.

Soil Texture Classification:
Soil separate equivalent diameter size (mm)

gravel > 2 mm
Sand 0.05 - 2 mm
very coarse 1 - 2 mm
coarse 0.5 - 1 mm
medium 0.25 - 0.5 mm
fine 0.1 - 0.25 mm
very fine 0.05 - 0.1 mm
Silt 0.002 - 0.05 mm
Clay < 0.002 mm (< 2 micrometer)


How to measure soil particle size ???

1. Mechanical sieving, if size > 0.05 mm

2. Sedimentation - Stokes� law, if size < 0.05 mm

Hydrometer method
Pipette method
Soil is dispersed, and mixed with water (soil suspension);
Settling velocity of individual particles depends on particle diameter;

Forces acting on soil particle are gravitation, buoyancy and drag forces,
and all depend on particle size;

The larger particles settle first � Stokes law
Since soils are a mixture of different size particles, soil�s are classified using the so-called
soil textural triangle.(see PDF link page 4)




I also wonder if the rover is using this method of
testing any soil properties and possible moisture content?
TIME DOMAIN REFLECTOMETRY (TDR)
The speed (v) at which the EM wave moves along the conductors and through the soil
is reduced as the dielectric constant of the soil is higher. Hence, an increase in water
content increases the soil�s dielectric, and subsequently increases the travel time of
the EM wave. The TDR method measures the travel time through the soil.


Surface area of soil affects its physical and chemical properties and is largely
determined by amount of clay present in soil




If the soil on mars is experiencing a 'Cementing' effect
that might be caused by a high salt content from
'brine' left after any water on mars was blown
off the planet by solar winds, due to a low gravatational
field around the planet, then the soil would in fact be
cohesive until broken up and made loose. again.


..

Wheni took a lok at the pictures of where the impressions were from the rover, etc, the bags, . I always thought that the soil on mars must be very oily.

Coz it looks it, leaves very good impressions and seems to move easily.