https://www.universetoday.com/164015/a- … rom-space/
Lava tubes and chambers attract a lot of attention as potential sites for bases on the Moon and Mars. They provide protection from radiation, from temperature swings, and even from meteorites. They beg to be explored.
Although I might like to see surface-built simulations of lava tubes, using sintering, yes existing lava tubes should be considered. It may not be that hard-to-get chemicals from the polar regions and bring them to the lava tubes for organic chemistry.
It might be nice to build roads inside of the lava tubes, as they may be expected to possibly have rugged floors. If we had small rocks that might do OK for it. Unfortunately, I would not expect small round rocks on the Moon, but if screening was done of Lunar regolith, you might size several grades of output. Then if you got the size of rocks suitable some kind of method might clean them of dust, I hope.
Then you could make a simple road system in the lava tubes.
You might also sinter Roman Arch type structures using the finer stuff.
Someday maybe some of the best lava tube sections might be pressurized by putting supports in, creating antileakage methods, and piling more regolith on top to prevent "'Blow-Outs".
At this time that is how I see it. Of course, you would need access though sky lights and methods of conveyance.
Done.
]]>https://www.spacedaily.com/reports/Chin … r_999.html
Chinese researchers are studying the possibility of setting up a safe, stable and long-term shelter in lunar lava tubes.
During Moon's early days, when the upper layer of lava flow cooled and hardened, molten rock may have continued to flow beneath, forming relatively stable and flat hollow pipe-shaped tunnels.
With years of geological activities, impact events and moonquakes, some shallow lava tubes formed accessible "skylights" after collapsing, opening the door to explore the underground world of the Moon, said Zhang Chongfeng from the Shanghai Academy of Spaceflight Technology.
Zhang, who is also the vice chief designer of China's Shenzhou series spacecraft and lunar landers, introduced the study at the 10th CSA-IAA Conference on Advanced Space Technology held recently in Shanghai.
He said that lava tubes are protected from the harsh environment of the lunar surface, which experiences extreme temperatures and is bombarded by radiation and micrometeorite impacts.
According to Zhang, his team and China's planetary geology experts have jointly conducted fieldwork on several lava caves in China to build up their understanding of lunar lava tubes.
There is a certain similarity between lava tubes on Earth and the Moon, Zhang said, adding that they can be divided into the vertical entrance tube and the slope entrance tube.
The lava tube with a vertical entrance is the major form of lunar tube people have found so far. They feature a collapsed skylight with a large amount of collapsed debris and soil accumulation at the bottom, requiring the deployment of vertical lifting facilities or entry through flight. The sloping entrance is a semi-collapsed structure, and therefore, there is a possibility of directly entering the inside of the lava tube along the collapsed structure. It is a preferred target that can be explored with a lunar probe.
The Chinese researchers have chosen lunar lava tubes at Mare Tranquillitatis and Mare Fecunditatis as the primary exploration targets and initiated the design of the exploration plans.
https://www.universetoday.com/160524/ex … -together/
Planetary exploration, specifically within our own Solar System, has provided a lifetime of scientific knowledge about the many worlds beyond Earth. However, this exploration, thus far, has primarily been limited to orbiters and landers/rovers designed for surface exploration of the celestial bodies they visit. But what if we could explore subsurface environments just as easily as we’ve been able to explore the surface, and could some of these subsurface dwellings not only shelter future astronauts, but host life, as well?
Living inside a Lava Tube or Mountains now considered 'in style' on Earth. An underworld city and Plans to build down not up.
Plan submitted to Sheffield City Council by architects Brightman Clarke for changes to a house in Sandygate Park, Lodge Moor shows the layout of the proposed subterranean leisure area including a swimming pool, snooker room, cinema and bar area.
https://www.yorkshirepost.co.uk/lifesty … me-3875681
A visit to Subnade: Tokyo’s survivor subterranean shopping center
https://japantoday.com/category/feature … ing-center
In Praise of Caves reveals how architects have burrowed into the Earth
https://www.ft.com/content/91dc50cb-5bf … 76e00df16d
Exhibition at the Isamu Noguchi Museum in Queens, New York, explores strange and wondrous subterranean spaces
This Boutique Hotel Is an Architectural Oasis Near Oaxaca’s Top Surf Beach
https://www.ft.com/content/91dc50cb-5bf … 76e00df16d
https://www.scmp.com/news/china/science … -long-term
These are still early designs, so the end plans for China's Moonbase may be quite different. Still, it's interesting to see the thinking at this stage. Housing the base in a lava tube seems such an obvious choice, it's hard to believe that decision will change. Apart from the benefits of shielding from cosmic radiation, new research shows these have stable temperatures of 17 Celsius.
It's interesting to wonder where exactly on the Moon this base will be. The Shackleton Crater on the lunar south pole has many advantages and NASA has been eyeing it for decades. It's interesting that the scientist working on this design references that the lunar south pole "could become really crowded".
]]>(th), here on Earth, mines have elevated air pressure.
Translating that to Mars, I would expect that you would need ~3 times the depth, to see a similar effect. But of course, the two planets would also have to have the same atmospheric composition and "Sea Level" starting pressure, modified by the altitude of the entrance to the mine shaft.
Atmosphere being compressible, there would be a curve in any graph for it.
As for liquid compression, water does not compress very much at all in general. But adding salt also changes the specific gravity.
So, spending a lot of time doing precise calculations might be a waste of energy, as we do not yet have the proper measurements of where unusually warm rock nearer the surface may encounter a water-based fluid.
About air pressure in a mine on Earth:
https://physics.stackexchange.com/quest … -in-a-mine
Further, yes the gravitation would go down a little bit as you go down, unless you approached a mascon.
Temperature would also affect air density, which would affect the total number of molecules in the mine shaft. That in turn would affect the air pressure.
In the end you have to make many presumptions, and doing the math, what have you gotten? Is it worth it? Or is it just herding out more than necessary to impress someone?
https://pr.princeton.edu/pwb/99/1213/mi … c%20gasses.
Quote:
The air pressure at Moser's work site was double what it is a sea level. The temperature of the virgin rock is 140°F. The mines must be continually flushed with fresh air from above to keep the heat below body temperature and to remove toxic gasses.
For Mars you would need about 2 divided by .38, for which close enough would be 6 miles.
If you put a door on top of the shaft and pressurized the top of the shaft to 1 bar, and if the composition of the air inside was the same as the Earth's atmosphere, and if the temperatures were comparable then I expect ~2 bar at the bottom of the shaft.
So, that could give a feel for it.
Martian atmosphere is denser than Earth Atmosphere, and the Shaft would be colder most likely, so if the compression at the top of the shaft were 5.5 millibar, I would expect > 11 millibar, as the Martian air is heavier than that of Earth.
So, then I think that -13 degC is capable of allowing microbial life, and the vapor pressure of that cold fluid would easily allow a liquid phase of brine. As long as the brine were not too salty then life would be possible.
Depending on the location, you may still be in the permafrost zone, but with salt you could still have a liquid.
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And so now I am going to preach at you. This is very much the problem with Academic thinking. To focus on precision and not approximations. Precision has its real values at times but also stops you "Seeing the forest for the trees".
Others have put it more simply. They think that there can be liquid aquifers deep down under the surface of Mars. But it is not proven. It is considered that ancient life may still exist in such aquifers if they do exist, but we do now know.
So we would have to make measurements.
To find evidence of such life, we should be considering cryovolcanoes for Mars. It is possible that they exist in the rift valley. That is one possible way that there can be a ice/water patch the size of the Netherlands at that location.
We have some sort of information about such types of things for Ceres, Europa, Enceladus, and Pluto.
We don't see them on Mars, if they currently exist, because if not covered in dust/regolith the ice will evaporate away.
And if covered, they would not look like ice volcanos.
By the way it seems that there are ancient mud volcanos on Mars.
https://www.planetary.org/space-images/ … %20freezes.
Quote:
Mud volcanoes on Mars Researchers at the German Aerospace Center say laboratory experiments show that Mars may have “mud volcanoes”—locations where watery sediments seep onto the surface. Because of Mars’ low temperatures and pressures, the mud quickly freezes.
https://thecosmiccompanion.net/mud-volc … 0of%20Mars.
Quote:
Mud volcanoes on Mars could be the cause of distinctive features that most researchers had thought were left over from ancient lava flows. Tens of thousands of channels spread out over the Martian surface. Hundreds of kilometers long, and tens of miles wide, these ribbon canyons reach far across the ruddy landscape of Mars.
So, places where we may think that water based fluids leaked to the surface might be good places to analyze what might be going on or did go on below the surface.
The Rift Valley may be artesian water volcanism. Or not.
Done.
]]>Thanks for this post! I'm hoping you will try to find a mathematician who might be willing to help you compute the pressure at various depths on Mars.
While the temperature is currently unknowable (because we humans have no on-site measuring equipment (that works)) the pressure at various depths would certainly be knowable.
The gravity decreases as the drill descends, and the temperature may be expected to increase.
There may be a sweet spot where pressure and temperature are "just right" and gravity is not too much less than at the surface.
With any luck you might be able to find (or enlist) a mathematician able to handle this problem.
Update a bit later .... this question may be solvable with a spreadsheet. If there is someone willing to contribute a spreadsheet for this purpose, NewMars is able to hold it in a Dropbox folder, so it is always available.
(th)
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