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#1 2015-09-10 09:55:44

Tom Kalbfus
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Registered: 2006-08-16
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Gigantic Ice Slab Found on Mars Just Below the Planet's Surface

by Charles Q. Choi, Space.com Contributor   |   September 10, 2015 09:01am ET
mars-crater-bramson-ua.jpg?1441834473
This image shows a digital terrain model of the crater investigated by the University of Arizona's Ali Bramson. Image released August 26, 2015.
Credit: American Geophysical Union

A giant slab of ice as big as California and Texas combined lurks just beneath the surface of Mars between its equator and north pole, researchers say.

This ice may be the result of snowfall tens of millions of years ago on Mars, scientists added.

Mars is now dry and cold, but lots of evidence suggests that rivers, lakes and seas once covered the planet. Scientists have discovered life virtually wherever there is liquid water on Earth, leading some researchers to believe that life might have evolved on Mars when it was wet, and that life could be there even now, hidden in subterranean aquifers. [Photos: The Search for Life on Mars]

The amount of water on Mars has shifted dramatically over the eons because of the Red Planet's unstable obliquity — the degree to which the planet tilts on its axis of rotation. Unlike Earth, Mars does not have a large moon to keep it from wobbling, and so the direction its axis points wanders in a chaotic, unpredictable manner, regularly leading to ice ages.

Although researchers have long known that vast amounts of ice lie trapped in high latitudes around the Martian poles, scientists have recently begun to discover that ice also is hidden in mid-latitudes, and even at low latitudes around the Martian equator.

    Learning more about past Martian climates and where its water once was "could help us understand if locations on Mars were once habitable," study lead author Ali Bramson, a planetary scientist at the University of Arizona in Tucson, told Space.com.

To look at ice hidden beneath the Martian surface, Bramson and her colleagues focused on strange craters in a region called Arcadia Planitia. This area lies in the mid-latitudes of Mars, analogous to Earthly latitudes falling between the U.S.-Canadian border and Kansas.

These odd craters are about 1,075 to 1,410 feet (328 to 430 meters) wide. Unlike most craters of their size, which are bowl-shaped, the craters the scientists focused on had terraces on their walls. Such terraces can form when layers of different materials, such as dirt, ice or rock, lie beneath a planet's surface.

When a crater forms because of a cosmic impact, the shock wave from the collision can push aside weaker materials more easily than strong ones.

"The result is terracing at the interface between the weaker and stronger materials," Bramson said in a statement.

Terraced craters of the size the researchers saw are virtually unknown outside of this area of Mars, Bramson said. However, all 187 craters the researchers studied have terraces, "which indicates something weird is going on in the subsurface," study co-author Shane Byrne, also of the University of Arizona, said in the same statement.

The researchers used data from the High Resolution Imaging Science Experiment (HiRISE) camera aboard NASA's Mars Reconnaissance Orbiter to create 3D models of the area's craters, which allowed them to measure the depth of the terraces. They next used the orbiter's Shallow Radar, or SHARAD, instrument to beam radar pulses at Mars, which helped them determine the composition of the layers making up the  terraces.

The ice the scientists found measures 130 feet (40 m) thick and lies just beneath the dirt, or regolith, or Mars.

"It extends down to latitudes of 38 degrees. This would be like someone in Kansas digging in their backyard and finding ice as thick as a 13-story building that covers an area the size of Texas and California combined," Bramson said.

Such an extensive ice sheet had never been seen at these latitudes before, study team members said.

In addition, this ice sheet is probably tens of millions of years old. "We believe this ice to be a relic of a past climate when snowfall could occur at these latitudes," Bramson said.

The researchers will now model the behavior of the ice at Arcadia Planitia to learn more about how it it could have stayed preserved for so long, Bramson said. She and her colleagues detailed their findings online Aug. 26 in the journal Geophysical Research Letters.

http://www.space.com/30502-mars-giant-i … y-mro.html

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#2 2015-09-10 10:01:12

Tom Kalbfus
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Re: Gigantic Ice Slab Found on Mars Just Below the Planet's Surface

Here is a good place to start a Mars colony, and 40 meters of ice/water would be enough to contain a habitat with 1 bar of atmospheric pressure inside, and plenty of water for both plants and rocket fuel. Write your congressman or congresswoman, may be we could convince them to finance a manned Mars mission with this information.

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#3 2015-09-10 13:05:00

Void
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Re: Gigantic Ice Slab Found on Mars Just Below the Planet's Surface

Really wonderful stuff Tom!

Here are some supplements:
https://en.wikipedia.org/wiki/Arcadia_Planitia
http://www.hou.usra.edu/meetings/lpsc2014/pdf/2120.pdf

I agree that the proposed thickness of the ice 130 feet, looks as ideal as one could hope for in the notion of having submarine or ice embedded 1 bar N2/O2 human habitats on Mars.

In this case, I am going to defer to GW Johnson's ideas about a regolith covered ice.  (Especially since it already is set up)  My only reservations are about the ability of a residual ice sheet floating on a body of water, to hold up the regolith, and not fold over.  (Ice cracking, sections tipping over).  If necessary, perhaps a light weight substance could be mixed with the regolith, such as Styrofoam beads/"Packing Peanuts".

I will relent on the windows of ice thing, because they are hard to do, and because going down 100 feet or so, the light is going to be quite attenuated anyway.  But maybe a few here and there, just to provide a minimum lighting to the water in the daytime.

For farming, I would propose artificially lighted gardens in the habitat, perhaps decorative trees the bear fruit, and maybe some tomatoes, and some herbs, or whatever, not the bulk diet for the people.

That is not to forbid putting light into the waters of the "Lake".  Most easily, such lights could promote the growth of various Photo Feeding organisms.  (Algae, etc.).

A bit harder would be pond weeds from the arctic, if there is no secondary enclosure inside the lake, because the bottom waters if the water is fresh will only be free from a spring turnover, type convection, if they do not rise above 39 degF.  But with simple enclosures inside the lake, it should be very possible to elevate temperatures inside the enclosures, and promote vascular plants from temperate and even tropical waters of the Earth.

Now for some hardy vegetables, I am going to suggest a new variation of the water embedded terrariums method.

I am going to suggest a canal trench be dug in the form of a ring or if you like, in the form of a torus. 

The width of the canal will be made ideal, for a covering which will be in the form of a torus "Arch".  The lower half of the torus will be embedded in the soil/ice, and most likely it will be desirable that it will have walls/a liner, to isolate liquid water within from soil/ice without.

The glass covering mated to this and above this will finish the torus.  So then if this can be pressurized to a minimum necessary pressure, you could maintain a liquid water circular canal within.

To maintain liquid conditions, of course the daytime sun will help.  Further, during the day, it would be possible to fill a tank with hot water, or even hotter pressurized steam.  That coming from solar concentrators.  During the night, this steam could be vented into the torus, to keep it's interior at satisfactory temperatures for the vegetables intended to be within.  The steam would most likely be "Quenched" into the cooling canal water, but perhaps other methods, such as some venting of steam into the air could be used as appropriate to the various options that are going to be available for growing plants.  And for a larger installation, such a process might support the turning of an electric generating turbine at night.

This process could also double as a method to generate a sort of "Distilled water", but of course it will be contaminated a bit when it condenses into the torus canal.

A further purpose of the canal, is transportation.  Although it is circular, there would be one point in the torus, where a observation "Deck" with windows would overlook a ring of barges.  The ring of barges would be movable, so each barge could move under this deck in turn as desired.  Robotic arms and camera's, and repetitive structures, would facilitate the gardening of vegetables in each barge.

If a very hardy vegetable could be grown in very low pressures, then well and good, you could have open barges with soil in the bottom.  But that will require the torus to hold larger pressures.  If the barges resembled the bottom half of a Styrofoam egg carton, then each "Cell" could have a cover.  At times the covers would be opened, such as planting and harvesting.  However, it might be possible to open them in between those events for some plants.  They might not be harmed too badly, if the low pressure is brief.

Additionally, it may be possible that each barge will have an on board regulation system for all of its cells, for watering, and injecting nutrients.

Anyway, this is another way, that may facilitate factory level farming on Mars, while minimizing the danger to humans for decompression, and radiation.  The "Observation deck" can be heavily shielded from radiation, and would have a means of egress to other locations through a tunnel(s).  Obviously, there will need to be an airlock to bring produce into the human habitats, and a means to eliminate and reuse plant waste.

And yes, this includes ideas borrowed from GW Johnson and Antius, and others.


And yes, that crater Tom,  it would be interesting to contemplate getting water into it from ice.  You might want light to get in in that case, in which case I suggest the "Ice Pillows" method.

Good Deal, I think smile

Last edited by Void (2015-09-10 13:46:14)


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

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#4 2015-09-11 00:52:47

Tom Kalbfus
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Re: Gigantic Ice Slab Found on Mars Just Below the Planet's Surface

I will relent on the windows of ice thing, because they are hard to do, and because going down 100 feet or so, the light is going to be quite attenuated anyway.  But maybe a few here and there, just to provide a minimum lighting to the water in the daytime.

Depends on how clear the water is. Perhaps a water filter could make the water a lot clearer. Perhaps plant life could grow closer to the surface. On Mars 40 meters of water is about 1 bar or water pressure, but plants can grow under one fifth of that pressure, so greenhouses can be placed under only 8 meters of water. One can swim up to the greenhouses and breath pure oxygen purging the blood of nitrogen bubbles as one ascends, One can enter the greenhouse through a moon pool, with a breathing mask on, as the green house will have a lower percentage of oxygen, and at that air pressure people will need to breath 100% oxygen in order to stay conscious.

Last edited by Tom Kalbfus (2015-09-11 00:58:23)

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#5 2015-09-11 05:57:12

Antius
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From: Cumbria, UK
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Re: Gigantic Ice Slab Found on Mars Just Below the Planet's Surface

Wow.  Up to half a million cubic kilometres of ice.  Certainly narrows down where we will be building the first base.

Getting the water out will be a challenge.  One would need to drill boreholes and inject heat into the ground to bring the ice to melting point.  Maybe a good case for a mobile inherently safe nuclear heat source.  A low pressure boiling water reactor with a water based shield perhaps?

Last edited by Antius (2015-09-11 06:02:24)

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#6 2015-09-11 09:52:24

Terraformer
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Re: Gigantic Ice Slab Found on Mars Just Below the Planet's Surface

This is probably going to have to wait for humans to be well established on Mars, but I'm now thinking we could dig a 40 m deep trench in the ice field, down to the ground; build suitable walls, which would have the buildings built up against them; and then cap it off with a roof containing 10-15 m of water. I do not know if that would provide sufficient light for crops, however, or whether the heat radiating from the habitat would be enough to keep it liquid. We could try it out in Antarctica or Greenland first.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#7 2015-09-11 10:32:14

Tom Kalbfus
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Registered: 2006-08-16
Posts: 4,401

Re: Gigantic Ice Slab Found on Mars Just Below the Planet's Surface

Terraformer wrote:

This is probably going to have to wait for humans to be well established on Mars, but I'm now thinking we could dig a 40 m deep trench in the ice field, down to the ground; build suitable walls, which would have the buildings built up against them; and then cap it off with a roof containing 10-15 m of water. I do not know if that would provide sufficient light for crops, however, or whether the heat radiating from the habitat would be enough to keep it liquid. We could try it out in Antarctica or Greenland first.

Water pressure builds up more quickly with depth on Earth than on Mars, you would need to go down only 10 meters to get to 2 bars of water pressure.

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