Starship Asterisk*

by **Qev** » Mon Oct 23, 2006 4:59 am

From what I understand, the vapor pressure of water at around 2C is roughly equivalent to the atmospheric pressure of Mars, meaning water below this temperature would not boil (although it will evaporate over time). So no, water will not always boil at the ambient pressure on the surface of Mars.

by **Dr. Skeptic** » Mon Oct 23, 2006 2:14 am

So here you are stating that the temperature of the water has nothing to do with whether it will boil or not. You don't know what you are talking about, or you are obviously a troll. The temperature of water in combination with the ambient pressure are the factors that determine whether it will boil or not. Boiling occurs when the energy of the water molecules is sufficient to escape Van Der Waals forces and become a vapor. Since you are denying this, you are clearly wrong.

You obviously did not read what I wrote - H20 will boil at 0°C or 1,000°C, in a liquid state even saturated with salts - liquid H2O will ALLWAYS BOIL in the ambient Martian atmosphere. So yes, the temperature of the H2O is irrelevant! (Troll)

Science 101

by **Dr. Skeptic** » Mon Oct 23, 2006 1:58 am

Once again, more pontification proving you do not have the scientific background to correctly interpret data. There is no proof of H2O in that crater, because it is your proclamation, that does not mean it is science or that it is present. You and I both know that your theory(s) would never hold up to peer review. By your responses it is apparent you cannot assess the scientific nature of the problems with your theories. It is not worth my time to spend hours trying to explain why your interpretations are in error when your responses is rant babbling around the point.

This is a science site, educated readers find your postings reprehensible and if your pseudoscience being the butt of the jokes around the water-cooler is disagreeable to you, it is time to move on. There are many other web places for you to go that would relish your science and conspiracy theories and may even add fresh augmentations to your story.

I am here only to stop the propagation of bad science.

by **eyecapitain1** » Mon Oct 23, 2006 12:52 am

Where have you been? Over the last two years opportunity's cameras have photographed HUNDREDS of dunes with clearly defined strata.
"Uniformity?" The saturation of sand will NOT be uniform but in a gradient. More at the lower levels(where there is more sand) and less at the top. GRAVITY and particle count assure this. Remember that water has surface tension and is cohesive. Moreso when in a salt brine solution. Ever used a syphon?.Same principal applies here.
"Blown" from the crater floor? What's that got to do with anything? The material we see in the floor is exatly the same in apearance as the sand dunes on the flats. Remember that the entire planet was engulfed in a year long GLOBAL dust storm just prior to the arrival of both Spirit and Opportunity. I'm betting the sands at Meridiani are pretty close or exactly the same as the rest of the sea basins on Mars.
I'm inclined to agree with Aichip in his assesment that you are a "troll" and not realy worthy of any more of our time.
"Superior?" Let's put that to a vote. Good people of this forum chime in. Has Skeptic provided one hint of proper scientific assesment of these topics or simply continued to make ambiguous statements founded on nothing more than his "say so"? To say nothing of his abrasive manners!

by **eyecapitain1** » Mon Oct 23, 2006 12:29 am

Well Done Aichip!!!
Let's see if skeptic has enough actual functioning neurons to "git while the gitting is good".
LMAO.likely not.

by **aichip** » Sun Oct 22, 2006 7:59 pm

Dr. Skeptic wrote:

So if I put out a glass of H2O on the surface of Mars it would not evaporate?

I replied:

It all depends on the temperature of the water, obviously.

Dr. Skeptic then wrote:

Obviously not, once again you are wrong on so many levels I don't know where to begin.

So here you are stating that the temperature of the water has nothing to do with whether it will boil or not. You don't know what you are talking about, or you are obviously a troll. The temperature of water in combination with the ambient pressure are the factors that determine whether it will boil or not. Boiling occurs when the energy of the water molecules is sufficient to escape Van Der Waals forces and become a vapor. Since you are denying this, you are clearly wrong.

Not only that, but you have completely ignored the technical references and statements of fact that they contain, documenting the experiments done that quantify the conditions on Mars and whether or not water will boil there. All you do is state "not so!" but then fail to provide any evidence or substantiation. You are definitely a troll.

Dr. Skeptic wrote:

Liquid H2O cannot exist on the surface of Mars.

Wrong, and proven so. Read the references and if you feel so inclined, do the experiments. That is the only way you will know for certain, since you refuse to believe what other scientists have found out that way.

Dr. Skeptic wrote:

At that atmospheric pressure H20 at any temperature will boil, even saturated with salts ice will evaporate

Wrong. The triple point is 0.01° C at 6.1 mb of pressure. Meridiani is at a higher pressure, and therefore (again, proven by experiment and by numerous researchers and scientists) water can in fact exist under those conditions, given that it is below the temperature at which it will boil. This can range up to 10° C or 50° F at the location of Opportunity.

Addition of salts extends the range that it will remain liquid in both directions - hotter and colder. Salts in solution form brine which has a significantly depressed freezing point, and also means that it takes more energy to make the water boil, thus extending its liquid range. This is basic chemistry, and again proven many times by many people. Repeating over and over like a child "it cannot be" does not make it so. You are a troll.

Dr. Skeptic wrote:

The boiling point of H2O on Mars is < 0° C.

Again, wrong and proven to be wrong.

Dr. Skeptic wrote:

Ice will also quickly evaporate

No, it will not. It will melt first. If it changes directly to vapor, it has undergone sublimation, not evaporation.

Dr. Skeptic wrote:

any exposed H20 will evaporate

Wrong. Read the referenced papers. They are factual.

Dr. Skeptic wrote:

Do you even know what sublimation means?

Of course. The question is, do you?

Dr. Skeptic wrote:

For ice to persistently exist it needs to be continually replaced

Prepare for a shock. See APOD for 20-July-2005:
http://antwrp.gsfc.nasa.gov/apod/ap050720.html

That is water ice in that crater. That is roughly 8 cubic kilometers of water ice. I do not see it being replenished, but the relative humidity on Mars stays right at 100% almost always. That is more than sufficient to prevent both evaporation and sublimation.

Or, look at this - APOD, 28-Feb-2005:http://antwrp.gsfc.nasa.gov/apod/ap050228.html

Frozen sea on the equator of Mars. Dust is covering it, and it succeeds in preventing both evaporation and sublimation. Again, you are proven wrong and by APOD itself. Do you trust the content of APOD?

Dr. Skeptic wrote:

At 100% humidity, H20 will precipitate out of the atmosphere leaving a uniform frost covering all surfaces as the temperature drops

Where have you been? This is observed all the time on Mars. Frost in the morning, which vanishes as the sun heats it. Here is more frost:
http://antwrp.gsfc.nasa.gov/apod/ap990112.html
Note that they show the erosion must be less than a year old. In other words, comparable to what we see on Earth.

So let's summarize.

I have proven that there is sodium on Mars, something you refused to accept even when I provided the technical papers and even NASA's own statements. I have proven the existence of carbon in the soil, which I also proved with technical papers and references directly from NASA. I have now proven that liquid water can exist on Mars given the present day conditions, also with technical papers and (if you look back through the Meridiani posts) references from NASA as well. You still refused to believe it.

I have now provided numerous links proving you wrong once again. Your responses have been childish "I say it's not so!" with nothing to back your position up or give it any substance. You are unwilling or unable to prove yourself. You are a troll and will remain a troll, and I will now ignore you. I will not do your research for you because a wise person does not cast his pearls before the swine.

Enjoy your brutish, childish existence and stay out of the way while the adults get something done. For the rest of the forum members, let's get down to business. As always, I invite serious intellectual discussion with rational and technically correct references.

by **Dr. Skeptic** » Sun Oct 22, 2006 7:06 pm

A change in the prevailing winds do to the topology changes created by the deposition of material causing erosion not uniform to the original deposition is a superior interpretation of the evidence. A complete and unbiased observation of the photo, one would see the darker material most likely blown from the crater floor is also clearly exposed in the foreground after the lighter material has eroded away. From experience I know that the % of H2O in the differing stratus is equal, if I am wrong this would be a very unique site different from all of the previous Rover stops and the known history of Martian climate would need to be rewritten.

by **eyecapitain1** » Sun Oct 22, 2006 3:45 pm

What you are saying is that the wind "preferentialy"deposited grains of singular consistancy at some levels,then came back to deposit smaller lighter grains,and then came back to add more heavy grains in another layer,and so on. Then came back after these strata "settled" and carved out the faces so we can see the clearly defined strata we now see on the crater rim?
This makes no sense to me at all. The wind should be moving the lighter grains more easily and the larger should be settling to the bottom. Wind would not produce strata in dry sand.(Case in point,The Sahara). Just sort them from heavy to lite and there would be a single demarcation and an intermixing of grains at the boundery.
Everything about the sands of Meridiani speaks of moisture being present in substantial volume. From the tight packing and crisp detail seen in the rover wheel tracks to the flow paterns seen literaly all over the meridiani planum so far explored by opportunity.
Wind is not the only mechanism working there. Why is it so hard to believe there is enough water on Mars surface today to be a working factor? It's clear that Meridiani was once a seabed! The sedimentary rocks are absolute PROOF this is a fact. And why would that water leave completely after the atmosphere thinned from global cooling?
The ground was saturated from the time the planet cooled sufficiently to form up a hard crust.
It's silly to think that the water that once comprised a vast ocean over two thirds of the planet would all simply "go away" ,as the planet core cooled and atmosphere thinned.
We KNOW where the oxegen in the Martian atmosphere went. The iron in the soil combined with it to give us the pretty rust red sand we see today.
We KNOW that a great deal of the hydrogen formerly locked in compound with O2 was split from compound by uv from the sun and lost to leakage off the top of the atmosphere to be snatched away by the solar winds.
We also know that the ground is STILL full of H2O from the many spectral scans of the entire planet. We also KNOW there is ample water in vapour hanging around in the atmosphere. There are cirostratus clouds in nearly every picture of the Martian sky. Spectral data of them taken by the HST proved them to be mostly WATER ICE.

What Aichip has suggested as a model makes perfect sense from a standpoint of observation of the area and KNOWN mechanics of the same actions right here on Earth. Frost heave and grain sorting are KNOWN to occure in the manner suggested.

by **Dr. Skeptic** » Sun Oct 22, 2006 3:20 pm

It all depends on the temperature of the water, obviously.

Obviously not, once again you are wrong on so many levels I don't know where to begin.

Liquid H2O cannot exist on the surface of Mars. At that atmospheric pressure H20 at any temperature will boil, even saturated with salts ice will evaporate, The boiling point of H2O on Mars is < 0° C. Ice will also quickly evaporate, any exposed H20 will evaporate. Do you even know what sublimation means?

For ice to persistently exist it needs to be continually replaced ≥ the rate of evaporation, where would this H2O be coming from atop the rim of a crater?

At 100% humidity, H20 will precipitate out of the atmosphere leaving a uniform frost covering all surfaces as the temperature drops, as the temp again rises surface sands will evaporate away their frost coverings, over time, leaving the surface sand with uniform % of H2O. If there were layers of sand saturated or containing a high % of H2O, it could not be seen from the surface. The only way your theory could be correct is if the topology were only day old and if Mars was much more active atmospherically and/or geologically.

by **aichip** » Sun Oct 22, 2006 8:46 am

Dr. Skeptic wrote:

I would need to write a book to cover all the errors in you facts, logic and false assumptions, so I'll pick one.

Yes, let's address the issue of assumptions. OF course, you are making the first mistake of associating the results of numerous techical papers by reputable researchers with me, and then simply ignoring them so they will go away, but that is another issue. Assumptions first.

Dr. Skeptic wrote:

So if I put out a glass of H2O on the surface of Mars it would not evaporate?

It all depends on the temperature of the water, obviously.

If I have a cup of water at room temperature and I place it in a vacuum chamber and remove most or all of the air, it will certainly boil. The key here is room temperature.

If I have that same cup of water and it is raised to 77° C (or about 170° F) and carry it to the peak of Everest, it will boil. Or put another way, water at that temperature cannot exist long on top of Mt. Everest.

Now, by direct experimentation, we see that the triple point for water at 6.1 millibars is 0.01° C, and that means that if the atmospheric pressure is greater than 6.1 mb, then water can exist as a liquid. But there is more. In a quote from the paper by Dr. Gil Levin, we see:

A word is in order about the applicability to liquid water on Mars of the triple point of water and Dalton’s Law of Partial Pressures lest they be applied incorrectly. The 6.1 mb pressure and 0.01° C temperature phase diagram coordinates identifying the triple point were determined for water as a closed, single component system, and in a pure state (that is, no substances other than water are present). On Mars, water exists in an open, multi-component system with atmospheric gases and extensive soil solutes. However, the laws of physics dictate that, when the atmosphere is saturated with water vapor, no net evaporation takes place. Under these conditions, when the temperature is between 0° C and the boiling point, and the total atmospheric pressure is at or above 6.1 mb, any water in the soil will be present in liquid form

The entire paper is here: http://mars.spherix.com/spie2/spie98.htm

The IAU defines zero elevation for Mars thus:

Zero elevation: Since Mars has no oceans and hence no 'sea level', a zero-elevation surface or mean gravity surface must be selected. The datum for Mars is defined by the fourth-degree and fourth-order spherical harmonic gravity field, with the zero altitude defined by the 610.5 Pa (6.105 mbar) atmospheric pressure surface (approximately 0.6% of Earth's) at a temperature of 273.16 K. This pressure and temperature correspond to the triple point of water.

Now, it is a fact that at the altitude of Meridiani (which is a couple of kilometers below zero elevation), the atmospheric pressure is typically 7.5 millibars and even reaches as high as about 11 millibars when summer arrives. The boiling point of water can range to as much as 10° C or 50°F during the course of the year, and rarely drops as low as the triple point. So a cup of chilled water will not boil nor can it, due to the laws of physics.

The assumption you have made is a simple one- room temperature. Your experience is such that you only imagined a cup of water at your familiar room temperature, which clearly cannot exist on the surface of Mars because it is above the boiling point. Chilled water can exist easily, however. Now let's also add the salts that are present in the soil and suddenly we have a range that is at least 30 degrees C wide for the existance of liquid water on the surface. That range changes seasonally but Meridiani is below zero elevation and as such liquid can remain as long as the temperatures permit.

Dr. Skeptic wrote:

It would boil, freeze and evaporate away exactly the way dry-ice (CO2) does in the Earth's atmosphere (sublimation), no matter how many salts are in it.

Sorry, I have just proven you wrong. Be man enough to admit it. You are the one who made unwarranted assumptions. Physics dictates that liquid water can exist on Mars in the Meridiani Planum area, and that has been demonstrated amply by many scientists. You are simply refusing to admit this fact.

Dr. Skeptic wrote:

What is the humidity in your freezer, have you ever noticed you ice cubes getting smaller?

Yes, it is called sublimation and it is driven by the introduction of dry, chilled air and advection. Freezers these days are typically "frost free". Do you know why?

Dr. Skeptic wrote:

You maybe able to fool the ignorant with you pseudoscience, but your logic is offencive to the educated. Every one of your arguments is given a pseudo spin, half truths, false assumption, and a product of an overly active imagination.

I am not trying to fool anyone. I am presenting the facts. Your lack of understanding and refusal to accept the truth is the problem. What makes you so unhappy is the fact that you cannot find a single flaw in my material or reasoning, and that is why you resort to insults. My findings are solid, and they violate your picture of reality. I will not apologize for the facts.

Dr. Skeptic wrote:

If you want to show me proof, show me an ecosystem.

I am limited to what the rovers can image, and what images are released. However, I did present images of fossilized leaves, along with the literally hundreds of fossil organisms on my site. It is a shame that the rovers have no manipulators, no water sensors, no chemical sensors, no halogen lamp for spectral reference, no soil moisture sensors... yet, they have returned a wealth of information. The images and the APXS data, along with the mini-TES data, have proven very useful.

Dr. Skeptic wrote:

I want to see evidence of organic compounds coating the rocks this life would feed from or other residual compounds that could only be created by presents of life

I would love for the rovers to have had organic sensors. Too bad that these were considered unimportant. But at least the pyrolitic release experiments on Viking found 7 of 9 soil samples had organic matter. That is a good positive indicator. Also too bad that NASA pretty much ignores that data.

Dr. Skeptic wrote:

If you were a real scientist you would know that your theory is a gross over statement of the available evidence.

If you were a scientist, you would realize that you have failed to admit that you have been proven wrong numerous times now. Two such issues were the presence of sodium and carbon in the soil of Mars. Another is the fact that liquid water can exist at Meridiani. I have made my living as a "real" scientist for years. Your opinions really don't mean much to me in the face of the facts.

Have a nice day.

by **Dr. Skeptic** » Sun Oct 22, 2006 3:47 am

No, that has already been explained by others far more qualified and many times. It does not evaporate because the relative humidity is nearly 100%. The air is already loaded with as much moisture as it can carry, and even with advection there cannot be any more evaporation. Just as you can only dissolve so much sugar in water, you can also only carry so much moisture in a mass of air. Afterwards, no more sugar will dissolve, and no more water will evaporate.

I would need to write a book to cover all the errors in you facts, logic and false assumptions, so I'll pick one.

So if I put out a glass of H2O on the surface of Mars it would not evaporate?

It would boil, freeze and evaporate away exactly the way dry-ice (CO2) does in the Earth's atmosphere (sublimation), no matter how many salts are in it.
What is the humidity in your freezer, have you ever noticed you ice cubes getting smaller?

You maybe able to fool the ignorant with you pseudoscience, but your logic is offencive to the educated. Every one of your arguments is given a pseudo spin, half truths, false assumption, and a product of an overly active imagination.

I strongly disagree with you not because I'm "fed" anything, If you want to show me proof, show me an ecosystem. On Earth solar energy is harvested by photosynthesis in plants at about a 10,000 to 1 mass ratio to support animal life. A few rocks with perfectly good inorganic explanations that somewhat resemble something that could have been created organically. I want to see evidence of organic compounds coating the rocks this life would feed from or other residual compounds that could only be created by presents of life ... that would be real science. If you were a real scientist you would know that your theory is a gross over statement of the available evidence.

by **aichip** » Sat Oct 21, 2006 6:51 pm

Dr. Skeptic wrote:

Not only would you need to prove the existence of a significant amount of H2O present in the sand

If the oceans of the world and all the lakes were removed at one stroke, it would not eliminate the underground sources that exist. Numerous springs, geysers, and volcanic vents still would be here, spouting water as they do. Mars did not lose its water entirely, it still has springs and geysers as well as some volcanic activity.

Is it unreasonable to accept that a planet with oceans would also have a hydrologic cycle? We already know of the glaciers from the frozen sea on the equator, the ice in craters, and the ice in the polar caps. Los Alamos produced a beautiful map of water distribution recently and even Viking showed the atmosphere to remain near 100% relative humidity nearly all the time.

So, as the axial tilt of the planet changes, it goes through the equivalent of ice ages, and as dust covers the glacier fields it protects a great deal of the ice from sublimation. Also, the extremely large quantities of salts in the soil act as an antifreeze, allowing the resulting brine to remain liquid at a much wider range than for fresh water. Here are some images of present day geysers on Mars from my site, and all have links back to the original NASA/JPL images on their site.

Sol 122 geyser from Opportunity: http://xenotechresearch.com/geyop122.htm
You can see the spherules have been blown back from the slot, and there is even a second smaller slot in the background above it. Clearly mud has run from the slot and material has been moved by whatever fluid emerged.

One frame from the large geyser field above Endurance Crater, Sol 114:
http://xenotechresearch.com/o114clr5.jpg

All along the left edge, and along the top left edge, we can see where the fluid emerged from under the rock slabs. Again, this soil is damp and cohesive. Desiccated sand will not cling together like this soil does.

Two geysers showing mud flow, also from Sol 114, Endurance Crater: http://xenotechresearch.com/o114clrc.jpg

Again, distinctive flow patterns of mud. Sand cannot hold this form without the presence of a liquid to help stick the granules together. There are many more images of geysers above Endurance Crater, brought together on this page: http://xenotechresearch.com/imo114.htm

Can we get more solid evidence than these images? Yes.

http://xenotechresearch.com/marsmud.htm Look closely at the top image. Water flow has created the patterns you see trailing behind the spherules. The "rock" is little more than sand and gypsum and salt. And, the next two images show on Sol 123 that the instrumentation arm was pressed against the mud and it bulged. The highly reflective nature of the soil is because it is wet. The bulge is not possible with desiccated sand. What fluid do you suppose might be holding the soil together so aggressively?

What about a picture of actual liquid water on the soil? Sure, no problem. This is a false color stereo image showing exactly that. http://xenotechresearch.com/O146stc2.jpg

You can see the trail from the end of an eruption as the geyser lost pressure and the water trailed away. The water is still present as a long, sinuous trail that breaks up into droplet trails. You must admit that something has landed on the soil there. the absorption from the infrared images closely match the absorption for liquid water. Go ahead and look at the radiometrically corrected images and see for yourself.

Here is a picture of another geyser just above Endurance Crater complete with a mud flow. Wind cannot create the pattern of flow and terracing you can see in the left bottom of the image.

http://xenotechresearch.com/o118clr1.jpg

I can also supply the images in stereo so you can confirm for yourself the three dimensional nature of these images, and these are just a scratch on the surface. I have sorted, processed and categorized hundreds of them. A child can see the flow patterns in the soil, and the fact that this cannot be dry sand.

In fact, let me provide you with a stereo image of the geyser slot itself that produced the water that made this flow. You can look right down into it. Wind does not make this sort of feature. Something emerged from under the rock slab and made this slot.

http://xenotechresearch.com/Vent3d2.jpg

Here is a full color stereo image set of a geyser from Sol 614, Opportunity.
http://www.xenotechresearch.com/marsgey6.htm

How do I know that something is coming from under the slabs? Easy. Cover the slabs with sand and their margins end up clean. Something emerges from beneath to clean just the outlines, as seen in this image from Sol 541:
http://marsrovers.jpl.nasa.gov/gallery/ ... 07L0M1.JPG
Look left of center at the slabs. Did wind selectively blow off just the edges? No. Steam or water emerging from beneath did it.

Finally (because I really don't have the time or inclination to post hundreds of images and explanations) I will wrap this up with spray zone from a geyser just inside Endurance Crater.
http://marsrovers.jpl.nasa.gov/gallery/ ... 94L2M1.JPG
The water has sprayed up and onto the soil, creating a bowl shaped washout area. If you want full stereo and color (plus the image containing both geyser and spray area) along with full color and stereo images of the geyser itself, I will gladly supply them.

Next point.

Dr. Skeptic wrote:

you would also need to explain the uniform layering of the H20 in the sand

The water is not uniform, it is throughout the soil. The heating is episodic and occurs over the seasons. As heat diffuses into the soil, it melts ice crystals and forms the layered appearance. Note that the layers are conformal with the dunes- start from the top and go down and they match the dune tops.

http://marsrovers.jpl.nasa.gov/gallery/ ... 75L0M1.JPG

Note how as the dune height changes, the layer height matches them. If layering happened first, it would conform to the bedrock layer, but it does not. How about this one?

http://marsrovers.jpl.nasa.gov/gallery/ ... 75L0M1.JPG
You will notice two interesting things. One, the layering is preferentially on the right sides of the dunes! Two, the layering is different on one side from the other. This means that the layers formed after the dunes. Do you know why they layer this way? This is very simple. Any experience with soil hydrology will tell you.

Wind moves through the soil and drives moisture to the lee side. Wind pressure forces the water that is liquid to migrate away from the wind. This is a known factor and here we see proof of it on Mars. Sand is porous and wind can in fact exert a large differential pressure on a sand dune. Here it is in spades.

Next point.

Dr. Skeptic wrote:

explain why the H2O is not evaporating

No, that has already been explained by others far more qualified and many times. It does not evaporate because the relative humidity is nearly 100%. The air is already loaded with as much moisture as it can carry, and even with advection there cannot be any more evaporation. Just as you can only dissolve so much sugar in water, you can also only carry so much moisture in a mass of air. Afterwards, no more sugar will dissolve, and no more water will evaporate.

http://dailyheadlines.uark.edu/5717.htm

Dr. Gil Levin has also done the experiments and shown the same results. The rate of evaporation is between 0.8 and 1.1 millimeters per hour under Mars temperatures and pressures. In the soil, where the surface of the granules prevents evaporation and there is a large quantity of salts, the rates are far, far lower. If you continue to insist that liquid water cannot exist on Mars, then you are just plain wrong. Sorry.

Dr. Skeptic wrote:

why the capillary effect isn't making the H2O layers bleed into other layers

It does. Note the different layering in the above NASA/JPL image showing the differences from front to back of the dune. Broad stripes of melted water diffusing into other zones, limited by freezing temperatures and heating, produces the stripes.

Dr. Skeptic wrote:

why the different layers seen to erode at the same rate

How can you tell what the rate of erosion is? The layers form in the dunes, sometimes the dunes blow around and new layers form. This is a dynamic system, not a static snapshot.

Dr. Skeptic wrote:

why the layers are uniform independent of solar angle

Look at how heat flows through a triangular cross section. Heat takes time to travel through materials, and when the ice does melt, the latent heat is still present in the water as it is blown through the soil or as it seeps into the dune. Sun angle can change significantly while the heat remains soaking into the sand.

Dr. Skeptic wrote:

and I can come up with more problems with your theory if you'd like

...and I can answer them. Gladly.

by **Dr. Skeptic** » Fri Oct 20, 2006 1:34 am

Not only would you need to prove the existence of a significant amount of H2O present in the sand, you would also need to explain the uniform layering of the H20 in the sand, explain why the H2O is not evaporating, why the capillary effect isn't making the H2O layers bleed into other layers, why the different layers seen to erode at the same rate (the presents of ice and/or H2O will reduce the erosion rate of sand), why the layers are uniform independent of solar angle, and I can come up with more problems with your theory if you'd like.

by **aichip** » Thu Oct 19, 2006 10:20 pm

Dr. Skeptic wrote:

I don't have time to look it up but I believe the surface H2O at Victoria Crater is less than .0001% - not enough to form any type of visual ice crystallization.

In other words, if I could show you strong evidence of present day water in significant quantities, might you be willing to concede that the layering is from ice crystals?

You see, this is one of the most important points I have tried to express and I have a huge body of evidence that liquid water is presently acting in the region and that it has been present all along. That in fact we are seeing present day erosion driven heavily by water and not as much by wind.

I can show that erosion rates are comparable to Earth right now, that erosion is presently erasing features and that therefore the features are constantly being renewed (or we could not se them) and that the erosion is causing the formation of the stems and is also causing other very visible signs that wind canot create.

Victoria already has shown the presence of fumaroles very clearly (which I can also demonstrate) and that they are active as we speak. If I can demonstrate this to you, are you willing to admit that there must be significant water in the region now?

by **BMAONE23** » Thu Oct 19, 2006 2:33 am

Given the current view of Victoria http://marsrovers.jpl.nasa.gov/gallery/ ... not_br.jpg you can see thet the current prevailing winds are blowing the localized dark soil to the north. Perhaps over time the winds have changed directions again and again causing the alternating layering of lighter surface (Planes) soils and darker crater soils.

by **Dr. Skeptic** » Thu Oct 19, 2006 2:26 am

It could be a combination of both if the crater wasn't within the 10% most arid locations on the planet and at a lower elevation. Active evidence of subterrainial melt and erosion is usually seen at crater and faults at depths over 50 meters - most of the surface H2O through out the Meridiani Planum has evaporated over the eons. I don't have time to look it up but I believe the surface H2O at Victoria Crater is less than .0001% - not enough to form any type of visual ice crystallization. Deposits of different colored materials is the only logical answer. I have only taught one terrestrial geology class so maybe a planetary geologist would be willing to set the record straight.

by **BMAONE23** » Wed Oct 18, 2006 5:08 pm

Two things could solve this. First, if the rover can easily dig a trench through the strata linear feature then they are probably dunes (now anyway). Second, if the features are hard pack and only exist on the eastrn and western slopes of the crater then they could have been exposed by wind blown sand type erosion of stratified layers. If you notice near the north end of the crater, the dark sand material is being blown out of the crater and carried of towards the NNW by prevailing winds. This would suggest that the predominant winds come from the south - southeast on the plains but tend to orient towards north within the crater.

by **aichip** » Wed Oct 18, 2006 1:30 pm

No, actually I understand your point quite well. You are basically saying the layers formed first and that consequently these are not dunes. I am saying that these are dunes and that the layers formed after the dunes blew in and are still forming today.

The difference is that you claim the layers are from deposition of differing materials and I claim that the sand is uniform but heating from the sun melts ice inside the dunes to create the layers.

by **Dr. Skeptic** » Wed Oct 18, 2006 12:39 pm

I think you misinterpred my point, the dunes were deposited post impact in different but relatively uniform strata, then non-linear erosion exposed the differences in the dune's layers as the age rings of a tree.

by **aichip** » Wed Oct 18, 2006 8:26 am

Sorry for the absence for a few days, under the weather.

Dr. Skeptic wrote:

What's not logical?

You seem to have overlooked a very simple, glaring fact about this. If the layering was present before the formation of the dunes, every dune would have the same layering at the same profile or height. This is not the case.

Dunes of different heights have the same layering, reaching the same heights respective to the dunes and not the bedrock - therefore the layering came after the dune formation. It cannot be otherwise. For your theory to be correct, the layering would have to proceed for however many years during which dunes would not form, and then suddenly, the sand would somehow etch away to leave what looks like dunes in every respect but would not be dunes.

Dunes march across the landscape and cannot carry layering with them, nor can they be formed in the conditions that would deposit thick layers of sand which would be changing over many thousands of years needed to create those layers. You are proposing that for ages, sand layering is the major force, yet one day, something changes and then layers no longer form but somehow the wind selectively removes material to make what looks like dunes but what is not dunes. And, that those stationary mounds of sand would somehow stand, containing layers, while some force (which could not be wind) removes much of the sand without touching the "dunes".

How do you propose that this happens without disturbing the layers of spherules? Notice that through all of this, the spherules are still on top of the soil. Have you actually noticed that?

Their presence on the surface and not below the surface proves that there is waer ice in the dunes. Really do think about this. The process is called frost heave. And when you realize that the spherules are on the surface only and not buried in the sand (as proven by numerous trenches dug by the rovers and the heatshield) then you see that water and water ice are present. There is no other explanation.

When that realization hits you, you then must admit that the heat from sunlight could diffuse through the upper thickness of the soil and melt some of those ice crystals and cause the layering very easily. And you then see that the layering is conformal to the dunes based on depth and thickness only. Now you can see a simple and plausible mechanism for these to be actual dunes, a common phenomenon, and to also support layering in exactly the manner we see.

One simple datum, the presence of water ice in the soil, exactly explains what we see without resorting to a complex theory that has thousands of years of deposition of one type of sand, then another, then back to the first, then the second, and so on, then suddenly an episode of some force removing sand to form what looks like dunes but cannot be because they must be stationary to support those layers.

by **Dr. Skeptic** » Mon Oct 09, 2006 11:48 am

aichip wrote:So what you are saying is that in the dunes, the sand was deposited in layers first, and then some of it blew away to leave layers? In other words, that these are not dunes, but hills of sand left from something eroding other sand away? That is not logical.

The dunes formed first, the layers formed afterwards. Think about it. Really.

What's not logical?

Deposit, then erosion - nothing unique about that.

by **harry** » Mon Oct 09, 2006 8:14 am

Hello All

Aichip's logic sounds great and possible and yet why not what Dr Skeptic says. Can we have a combination effect or is it one or the other.

by **aichip** » Mon Oct 09, 2006 5:01 am

So what you are saying is that in the dunes, the sand was deposited in layers first, and then some of it blew away to leave layers? In other words, that these are not dunes, but hills of sand left from something eroding other sand away? That is not logical.

The dunes formed first, the layers formed afterwards. Think about it. Really.

by **Dr. Skeptic** » Sat Oct 07, 2006 4:47 pm

Deposit striations will be uniform, ice melt is dependent on solar energy, (incident angle, exposure duration) producing lesser defined horizontal striations in proportion to exposure.

by **aichip** » Sat Oct 07, 2006 2:16 pm

Dr. Skeptic wrote:

if the layers were near the floor of the crater you theory may have a chance - how many million photos would you like showing concentric layering of sand dunes?

What is your point? A NASA scientist has already theorized that up to half the sand dunes' content could be water ice crystals. Why would they preferentially melt at the floor and not at the rim? The layered dunes certainly appear to show this behavior.

As for layered dunes, there are thousand of images in the MER data already. I don't think a few more will make much difference.

Starship Asterisk*

Victoria Crater (APOD 2 Oct 2006)

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Unique? Skeptic?

Amen

obviously you are a troll

I don't get it Skeptic.

assumptions

piecemeal examination of points

Lack of water

the point

Dune Layering

Re: Deposit striations and dunes

Deposit striations and dunes

Why the crater floor?