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#1 2018-01-06 20:19:54

Void
Member
Registered: 2011-12-29
Posts: 2,364

Sub Surface Ice on Mars

Topic: Sub Surface Ice on Mars
For whatever it might matter.
------
I just read Elon Musk's Three basic Rules to Get that extra dose of courage every day.
He is a bit young to be advising me, but of course he obviously actually knows what he is doing at least some of the time.  (Unlike myself who mostly bumbles).
So to bore you futher smile
1)Take risks as long as you fail cheep.  Learn fast and move on.
2) Is it worth a try?
3) Have a Viking spirit.
1) I have learned that all I have to risk here is strange harrasments.  I don't pay much if I don't care.  (And I don't) smile
2) It is worth a try.  If I am wrong, then it at least narrows the explainations by eliminating the one I proposed.  That is progress in any case.
3) Have a Viking Spirit.  No problem, I am half northern Swede by blood.  And probably a bit of Norwegian and Dane from the other side as well.
------
History:
In the era of Carl Sagan, they did their best estimates on the survival of ground ice on Mars on the basis of the infomation they had.  They did not factor in strange salts.  They also did not fully contemplate the migration of polar deposits if the polar tilt were to change.
------
Since Then:
The latest ideas for low latitude ice are the migration of the poles and fossil snowfalls burried by dirt.  Also observed are apparent glaciers at higher lattitudes.
For the glaciers if they are real, I do support the likelyhood of snowfall from a previously different Martian climate, most likely due to a changing tilt of axis.  It seems the most likely idea for it.
------
Other possible episodic methods to distribute ice to low lattitudes:
I suggest that if a volcano did erupt, it is quite possible that it would emit a lot of hydrocarbons.  I am including this just to be as complete as possible.  For Earth, a volcanic eruption could cause cooling due to dust.  But I expect that on Mars the dust would settle much faster, and if there were greenhouse gasses emitted in the eruption, they might alter the climate for a bit before they were elimnated from the atmosphere.  This is not an idea I am particularly championing, just mentioning it.
------
OK, however the ice gets deposited at low lattitude, how does it survive beyond the time limit that is expected.
1) An extreme method preserves it, maybe.
2) An existing method to replenish it is active today, speculation.
------
1) An extreme method preserves it: (Maybe) 
This was my original interest.  I was thinking that a combination of dirt overlying ice with a salt coating might cause it to evaporate much more slowly than would be expected.  That could be true.  I originally thought that the original ice deposite might have had a bit of salt in it, and when its outer portions evaporated off, a layer of remnant salt would protect the remaining ice body.  This could actually be true in some cases.  But I have no proof.
------
2) An existing method to replenish it is active today: (Speculative)
From that I began to wonder about temporary phases of liquid brine on the outer surface of that ice body.  Then I remembered the Phoenix lander.  Apparent droplets of liquid water were observed on the lander legs.  They actually swelled in size.  They identified the salt helping this process as being Calcium Perchlorate.  The article I read speculated that Calcium Perchlorate may be ubiquitous to the Martian surface.  So this sort of thing may be possible many places on Mars.
Day to night, on Mars at lower latitudes the temperatures and humidity swing to extremes.
Deeper in the ground, I would expect that these day and night temperature swings, do not alter the temperature much.
However, I expect that seasons which are almost twice as long as those on Earth may alter the thermal situation several inches down quite a lot.
So I would expect that in the colder season the ice body with presumed Calcium Perchlorate in it to get colder.  The normal expectation would be that either salt crystals could condense out of any brine liquid, or a less briny liquid could freeze into water crystals (With some salt), and that a more briny fluid would remain.  (If any of the materials were a liquid brine in the first place).
The Earths North Polar ice pack is somewhat like that.  You would expect that in the winter, the ice would freeze more solid and would squeeze more salty brine out of it, and that brine would exit downward into the Polar Sea / Arctic Ocean.
So, why would this not happen on Mars in it's soil?  Well, I thought that at first it would.  However, over the ages, if a permafrost (Hydrated with ice) layer were layed down, then the brine squeezed out would most likely have to squirt upward, because the lower layer of less salty ice perviously deposted would be too impenetrable.
So then when the season become more warm and more humid, and if some degree of seasonal heating were felt on that briny upper layer, it might absorb mositure from the atmosphere each warm season,  and then again deposit some of it to the permafrost below each cold season.
------

It always bothered me why apparently solid ice was revealed when the Phoenix blew the dirt off of the top of it.  I would have expected dirt with ice in it.
------

It is my speculative opinion that it is possible that #1 or #2 or both do occur.
A notion of why it appears that some type of water deposit are show data at lattitudes lower than expected today on the planet Mars.
smile

Last edited by Void (2018-01-06 20:45:09)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#2 2018-01-07 05:19:07

louis
Member
From: UK
Registered: 2008-03-24
Posts: 3,817

Re: Sub Surface Ice on Mars

I think you raise a lot of interesting questions about water presence on Mars. To get in a dig against NASA - isn't it amazing we still don't know the answers to these questions after 40 years plus of landers visiting the planet?

We do have water signature measurements for the planet which must surely suggest that there is a lot of water in the material at the surface. But I don't recall NASA ever having confirmed that is the case. A permafrost layer sounds the best bet to me.


Void wrote:

Topic: Sub Surface Ice on Mars
For whatever it might matter.
------
I just read Elon Musk's Three basic Rules to Get that extra dose of courage every day.
He is a bit young to be advising me, but of course he obviously actually knows what he is doing at least some of the time.  (Unlike myself who mostly bumbles).
So to bore you futher smile
1)Take risks as long as you fail cheep.  Learn fast and move on.
2) Is it worth a try?
3) Have a Viking spirit.
1) I have learned that all I have to risk here is strange harrasments.  I don't pay much if I don't care.  (And I don't) smile
2) It is worth a try.  If I am wrong, then it at least narrows the explainations by eliminating the one I proposed.  That is progress in any case.
3) Have a Viking Spirit.  No problem, I am half northern Swede by blood.  And probably a bit of Norwegian and Dane from the other side as well.
------
History:
In the era of Carl Sagan, they did their best estimates on the survival of ground ice on Mars on the basis of the infomation they had.  They did not factor in strange salts.  They also did not fully contemplate the migration of polar deposits if the polar tilt were to change.
------
Since Then:
The latest ideas for low latitude ice are the migration of the poles and fossil snowfalls burried by dirt.  Also observed are apparent glaciers at higher lattitudes.
For the glaciers if they are real, I do support the likelyhood of snowfall from a previously different Martian climate, most likely due to a changing tilt of axis.  It seems the most likely idea for it.
------
Other possible episodic methods to distribute ice to low lattitudes:
I suggest that if a volcano did erupt, it is quite possible that it would emit a lot of hydrocarbons.  I am including this just to be as complete as possible.  For Earth, a volcanic eruption could cause cooling due to dust.  But I expect that on Mars the dust would settle much faster, and if there were greenhouse gasses emitted in the eruption, they might alter the climate for a bit before they were elimnated from the atmosphere.  This is not an idea I am particularly championing, just mentioning it.
------
OK, however the ice gets deposited at low lattitude, how does it survive beyond the time limit that is expected.
1) An extreme method preserves it, maybe.
2) An existing method to replenish it is active today, speculation.
------
1) An extreme method preserves it: (Maybe) 
This was my original interest.  I was thinking that a combination of dirt overlying ice with a salt coating might cause it to evaporate much more slowly than would be expected.  That could be true.  I originally thought that the original ice deposite might have had a bit of salt in it, and when its outer portions evaporated off, a layer of remnant salt would protect the remaining ice body.  This could actually be true in some cases.  But I have no proof.
------
2) An existing method to replenish it is active today: (Speculative)
From that I began to wonder about temporary phases of liquid brine on the outer surface of that ice body.  Then I remembered the Phoenix lander.  Apparent droplets of liquid water were observed on the lander legs.  They actually swelled in size.  They identified the salt helping this process as being Calcium Perchlorate.  The article I read speculated that Calcium Perchlorate may be ubiquitous to the Martian surface.  So this sort of thing may be possible many places on Mars.
Day to night, on Mars at lower latitudes the temperatures and humidity swing to extremes.
Deeper in the ground, I would expect that these day and night temperature swings, do not alter the temperature much.
However, I expect that seasons which are almost twice as long as those on Earth may alter the thermal situation several inches down quite a lot.
So I would expect that in the colder season the ice body with presumed Calcium Perchlorate in it to get colder.  The normal expectation would be that either salt crystals could condense out of any brine liquid, or a less briny liquid could freeze into water crystals (With some salt), and that a more briny fluid would remain.  (If any of the materials were a liquid brine in the first place).
The Earths North Polar ice pack is somewhat like that.  You would expect that in the winter, the ice would freeze more solid and would squeeze more salty brine out of it, and that brine would exit downward into the Polar Sea / Arctic Ocean.
So, why would this not happen on Mars in it's soil?  Well, I thought that at first it would.  However, over the ages, if a permafrost (Hydrated with ice) layer were layed down, then the brine squeezed out would most likely have to squirt upward, because the lower layer of less salty ice perviously deposted would be too impenetrable.
So then when the season become more warm and more humid, and if some degree of seasonal heating were felt on that briny upper layer, it might absorb mositure from the atmosphere each warm season,  and then again deposit some of it to the permafrost below each cold season.
------

It always bothered me why apparently solid ice was revealed when the Phoenix blew the dirt off of the top of it.  I would have expected dirt with ice in it.
------

It is my speculative opinion that it is possible that #1 or #2 or both do occur.
A notion of why it appears that some type of water deposit are show data at lattitudes lower than expected today on the planet Mars.
smile


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#3 2018-01-07 10:30:30

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 12,701

Re: Sub Surface Ice on Mars

Electronic measurement is not the same as the real thing, drill, drill, drill.....then you know for sure that what you were reading is real...

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#4 2018-01-07 11:39:46

Void
Member
Registered: 2011-12-29
Posts: 2,364

Re: Sub Surface Ice on Mars

Hi Spacenut.  Yes, eventually facts need to be established.

Louis.  Thanks for stopping by.

This thing is very exciting I think:
http://www.sciencemag.org/news/2017/08/ … fe-seekers

But the ice patches also present a puzzle. According to current models of Mars’s climate, equatorial ice can’t persist for more than 125,000 years or so, Wilson says. That’s because it would gradually sublimate into the atmosphere, even if buried beneath a shallow layer of insulating soil. If ice truly exists there, it could be evidence of a shift in Mars’s rotational axis within that time window, Wilson explains. Unlike Earth, Mars doesn’t have a large moon to help stifle the long-term wobble of its orbital axis. And if the planet’s axis were tilted more than its current 25°, some polar cap ice would have sublimated and moved to lower latitudes. Wilson acknowledges that the explanation is unlikely, however, given that Mars’s rotational axis shouldn’t wobble on such fast time scales. Another possibility, he says, is that the soil also provides a vapor barrier to help stifle sublimation as well as physical insulation.

I have labeled my suggestions as Maybe and Speculations.

But I say that as Mars is not what Earth is, it often disappoints us, but at the same time it may offer things that cannot be found very well on Earth.  We just aren't familiar with what they are, because we haven't experienced them very much.

We should be looking for the unusual.

I am going to next mess around with BFR up at the "Adults" table.  For exactly the reasons you have said Spacenut.  The need for facts.

Last edited by Void (2018-01-07 11:44:12)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#5 2018-01-07 12:43:07

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,185
Website

Re: Sub Surface Ice on Mars

An ocean drying up gets very salty,  at least in our experience here on Earth.  Even initially freshwater lakes do this salinity thing as they dry up (example:  Great Salt Lake). 

There once seems to have been an ocean in the northern lowland region on Mars.  Like ours,  it was probably initially salty,  and went extremely saline as it dried up.  Any remnant ice from that source should be salty.  But not all the water on Mars was initially salty,  so any remnant ice from lakes that dried should be much less salty.  Any remnant snowfall deposits shouldn't be salty at all.

You don't need salt for ice to survive near the surface at current Martian conditions.  You only need about 6 inches or so of dirt cover.  We already saw that with the small lobes of ice,  that sublimed after being uncovered by the polar lander.  It's not so much the weight of the dirt cover,  it's the flow friction of the water vapor percolating the very serpentine path around the particles. 

The outlet pressure is local Mars barometric,  upstream is significantly higher,  and it doesn't take that much frictional path length to raise the vapor pressure adjacent to the ice to something stable,  with an exceedingly slow sublimation rate.  Expose the ice to Martian barometric,  below the vapor pressure for ice at that temperature,  and the sublimation rate is orders of magnitude higher.  That's precisely what the polar lander saw.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#6 2018-01-07 13:20:25

Void
Member
Registered: 2011-12-29
Posts: 2,364

Re: Sub Surface Ice on Mars

Nice alternate information GW.  Good to have contact again.

However ice may exist near the equator of Mars, it is important to establish a greater certainty about it as Spacenut has suggested.  However, less gifted I may be I am working on that issue.

I welcome your methods as well as others.


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#7 2018-01-07 15:08:29

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 12,701

Re: Sub Surface Ice on Mars

The Red Dragon mission that was scrubbed would have been capable of the complete test with retro propulsion and drilling as well as sample return so its Nasa's fault for not paying to get it done.

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#8 2018-01-07 15:11:30

Void
Member
Registered: 2011-12-29
Posts: 2,364

Re: Sub Surface Ice on Mars

Well, it has to be expected to deal with B.S.  Just have to cheerfully try again.  (Easy to say).


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#9 2018-01-07 16:38:38

louis
Member
From: UK
Registered: 2008-03-24
Posts: 3,817

Re: Sub Surface Ice on Mars

I think that is the only explanation for why we are getting such consistent Northern Hemisphere water signature readings from orbital surveys of Mars...that there is a very generalised permafrost layer as you get in Siberia on Earth.  Of course NASA next mission is a seismic study. They have no real interest in establishing the answer to this question in my view.

GW Johnson wrote:

You don't need salt for ice to survive near the surface at current Martian conditions.  You only need about 6 inches or so of dirt cover.  We already saw that with the small lobes of ice,  that sublimed after being uncovered by the polar lander.  It's not so much the weight of the dirt cover,  it's the flow friction of the water vapor percolating the very serpentine path around the particles. 

The outlet pressure is local Mars barometric,  upstream is significantly higher,  and it doesn't take that much frictional path length to raise the vapor pressure adjacent to the ice to something stable,  with an exceedingly slow sublimation rate.  Expose the ice to Martian barometric,  below the vapor pressure for ice at that temperature,  and the sublimation rate is orders of magnitude higher.  That's precisely what the polar lander saw.

GW


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#10 2018-01-08 06:01:42

elderflower
Member
Registered: 2016-06-19
Posts: 879

Re: Sub Surface Ice on Mars

Any ice may have been covered in large thicknesses of windblown dust, volcanic ash, maybe lava flows over that, or several more layers of ash or both. If it were thick enough I would expect to find that the ice would remelt at depth, assisted by the redissolving salts and freshly leached salts from the rocks. Then you might get those massive floods and surface collapses when a path to the surface is eventually opened.

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#11 2018-01-13 16:25:43

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 12,701

Re: Sub Surface Ice on Mars

Its not just about try again for missions its about funding, design and then a launch vehicle to make it happen. The tantilizing water found at the edge of cliff faces, is going to make it hard to test for unless it extends into the hillsides where they have been found. So where is the mission planning to drill? That is the problem as this if its confirmed to be energy processing at the lowest levels makes a big deal for all that would go to mars. It makes life not only possible but so much more.

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#12 2018-01-13 22:26:11

Void
Member
Registered: 2011-12-29
Posts: 2,364

Re: Sub Surface Ice on Mars

https://www.space.com/38330-water-ice-m … uator.html
http://www.sciencemag.org/news/2017/08/ … fe-seekers
quote:

Water ice found near Mars’s equator could entice colonists and life-seekers
By Sid PerkinsAug. 16, 2017 , 1:45 PM
Scientists have discovered substantial deposits of water ice buried in shallow soils near Mars’s equator. The find could spur hopes for astrobiologists seeking life on Mars or future colonists seeking a supply of water, but it also raises a mystery for climate scientists.
The findings come from a reanalysis of data from NASA’s Odyssey spacecraft, which began orbiting Mars in 2001 and is the oldest functioning mission at the planet. One of Odyssey’s instruments measures the neutrons kicked up from the martian surface by cosmic rays striking the planet. From these neutron counts, scientists can infer the amount of hydrogen—and thus, presumably, the amount of water—present in the uppermost meter or so of soil. In small amounts, the water can take many forms—either in hydrated minerals or as small ice particles stuck between particles of sand or silt. But when the inferred abundances rise above 26%—as they do in some regions—scientists are pretty sure that bulk ice sits just below the surface, says Jack Wilson, a planetary scientist at Johns Hopkins University’s Applied Physics Laboratory in Laurel, Maryland.
That Mars holds stores of ice is not news. At the poles, there are permanent caps made up of frozen water and carbon dioxide. And as far back as 2002, researchers using Odyssey’s neutron instrument reported evidence of water in the subsurface at high latitudes. The evidence was strong enough that NASA sent the Phoenix lander to explore these regions. When the lander’s robotic arm scratched at the hardscrabble soil in 2008, it found ice just below.

Now, here is what I want to explore:  Calcium Perchlorate

I do know that if you alter temperature of a salt solution, you can with a falling temperature cause crystals of salt to form as a solid (Of course).  But this would leave a less briny solution or a less briny ice.

So when the temperatures warmed up, might Calcium Perchlorate crystals in the soil absorb humidity from the atmosphere?  So then as seasonal change, is there the possibility of a condensation process of this kind near or at the equator?

Could I be wrong?  Yes.

Should I be ashamed for asking?  No.

If you could establish a settlement on Mars, would you prefer to do it at high latitudes or near the equator?

That's why I would like scouting missions.  Dead settlements do not a civilization make.

Last edited by Void (2018-01-13 22:33:08)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#13 2018-01-14 05:30:26

elderflower
Member
Registered: 2016-06-19
Posts: 879

Re: Sub Surface Ice on Mars

Falling temperature of a solid solution will proceed until the solution reaches a state where it has an excess of one or other of its components. Further cooling will result in the rejection of the excess component. If the solution has a eutectic (as a great many do) the temperature will continue to fall towards the eutectic temperature and the overrepresented component will continue to be rejected from the solution. For common salt this temperature is about -21 C ( 0 F).
In sea water, which is way under the common salt (Sodium Chloride) eutectic composition, freezing of the water component starts around -2 C  and water continues to freeze out as the temperature falls. In this way, once the brine remaining has drained from the ice, sea water ice may be used for drinking. This usually takes a couple of years, as I understand.
A really concentrated brine will reject salt crystals instead as its temperature falls, until it reaches the eutectic composition. This will then freeze at that composition. For common salt this is about 23% salt in water.
For real Mars situations there may be mostly Sodium Chlorate in the brine, but there may be other things as well so the eutectic may not be quite so simple. Multiple salt species in the solution will generally further depress the freezing point.

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#14 2018-01-14 10:36:01

louis
Member
From: UK
Registered: 2008-03-24
Posts: 3,817

Re: Sub Surface Ice on Mars

I am thinking about this in terms of landing sites for Space X's BFR.

Would you get a water signature from somewhere covered in a lava flow? I doubt it...Also, I think the orbiting surveyors can identify where there are large accumulations of sand or ash,or indeed whether there is hard rock below. 

My sense is that Space X will be able to identify plains covered in firm but removeable soil (clay or sandy regolith) where there is a strong water signature. I think hitting a permafrost layer of ice within a a couple of metres is almost guaranteed.

But if they can ensure that the location is not too far  from exposed water ice, then I think they have their insurance policy.

elderflower wrote:

Any ice may have been covered in large thicknesses of windblown dust, volcanic ash, maybe lava flows over that, or several more layers of ash or both. If it were thick enough I would expect to find that the ice would remelt at depth, assisted by the redissolving salts and freshly leached salts from the rocks. Then you might get those massive floods and surface collapses when a path to the surface is eventually opened.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#15 2018-01-14 12:29:51

Void
Member
Registered: 2011-12-29
Posts: 2,364

Re: Sub Surface Ice on Mars

I understand your position Louis.  To be practical, I have decided to simply be alternate counsel.  I am not dictating a specific process, but offering what I hope is expanded awareness, and the opportunity to choose for the best.

Similarly I want the same from other members.

Last edited by Void (2018-01-14 12:30:21)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#16 2018-01-15 04:51:51

elderflower
Member
Registered: 2016-06-19
Posts: 879

Re: Sub Surface Ice on Mars

I am a bit concerned that heat from landing a large rocket on an icy, permafrost surface might destabilise the soil and allow the ship to fall over. Skycrane landings avoid this but BFR wont be able to do that- will it?

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#17 2018-01-15 11:22:28

louis
Member
From: UK
Registered: 2008-03-24
Posts: 3,817

Re: Sub Surface Ice on Mars

I think this is why the Space X plan is to land cargo BFRs two years ahead of the human BFR. So during the following 18 months or so, it can be confirmed that the cargo BFRs' have landed on firm ground and that robot rovers have confirmed there is suitable firm ground for a landing zone for the human BFR.  Otherwise, they would just land all 3 BFRs together. I think it's staged for this very reason.


elderflower wrote:

I am a bit concerned that heat from landing a large rocket on an icy, permafrost surface might destabilise the soil and allow the ship to fall over. Skycrane landings avoid this but BFR wont be able to do that- will it?


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#18 2018-01-15 11:53:48

elderflower
Member
Registered: 2016-06-19
Posts: 879

Re: Sub Surface Ice on Mars

Or maybe staged cashflow, Louis!

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