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If it had water...
...and if that water outgassed...
...considering that the Earth's atmosphere apparently came from outgassing...
...could Luna have once had an atmosphere?
If it had an atmosphere, could some of it have remained behind? Say, as nitrate beds?
Use what is abundant and build to last
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Alright, I am entertained by this
I am starting to ask seriously "Why do I do this?"
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The methods of creation of Moons, currently accepted are:
1) Accretion in a subdisk, Jupiter, and Saturn as some examples.
2) Capture, Triton as a proposed example.
3) Collision Earth Moon as a proposed model.
I honestly don't know, but I get riled up when pseudo priests try to mandate obedience to a popular notion, when their function is supposed not to be religious in nature, but scientific.
For Earth's Moon, I propose an alternative model, where the Moon begins like one of Jupiter's, moons, but is indeed modified by collected material added to the Moon from impactors ejecting materials from the Planet Earth.
If alternately the Moon was created from a single impact event, then we will need a notion of how such a thing retains Hydrogen compounds. I do not say that it is not so, but that the alternate method violates the presumptions of the progenitors of the single impact formation notion.
My patience has limits, I do not require simplified mind priests masquerading as scientists, in the scientific realm. They are not useful, but really a trouble not needed.
(Not for you Antius):
Stick to reading books and not writing them if you are going to be a priest!
Last edited by Void (2016-11-29 12:57:28)
I am starting to ask seriously "Why do I do this?"
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According to my terraforming book, solar wind sputtering is capable of removing 100kg/s from the lunar atmosphere. This rate is sufficient to keep the lunar surface at hard vacuum condition under present rates of voltaile release due to outgassing and cometary impact. At this rate of loss, an atmosphere with surface pressure 1 bar would be completely stripped away in about 700 million years. The nascent sun was far more tempestuous than we know it today. The Martian atmosphere was largely stripped away during its first billion years. Rates of loss are comparatively modest today. We can speculate that something similar could have happened on the moon, hastening its atmospheric depletion. An original sulphur dioxide and CO2 atmosphere might have been shielded by a magnetic field in the earliest days. But tidal braking would have removed it within a few hundred million years at most. Also, the late heavy bombardment would have blown away anything that remained.
Last edited by Antius (2016-11-29 16:55:58)
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I am comfortable with what you say Antius. For now I think it is a best argument for how the Moons surface and atmosphere would be like it is even with a large amount of water and perhaps other volatile materials in it's deeps.
If all of this is true, then the Moon may have considerably greater value that what has been supposed for a "Dry Rock" Moon.
I am starting to ask seriously "Why do I do this?"
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if the Moon has water, it would be a great place to build a space station. The Moon has the same availability of Solar Energy as does the Earth, it is in near real time communication with the Earth, you can control robots on the Lunar Surface from the Earth, you could even build a lunar habitation by remote control using teleoperated robots from the Earth. The robots we have these days are fairly capable, the technology in autonomous cars could be used to great effect on the Moon, and you could get a lot done. I'd say build a home on the Moon using teleoperated robots and when its finished, you can send people there. There might even be a market for such a place based on real estate values and the unique experience of Lunar gravity. The first step may be to build a Lunar hotel near the north or south poles of the Moon, the sell tickets to get there and for stays at the hotel. With abundant water, it would be cheaper to build in ground swimming pools and other standard features of hotels.
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Any deep water may or may not be accessible. Perhaps it does vent from cracks, perhaps not.
It is certainly worth verifying Tom.
I am starting to ask seriously "Why do I do this?"
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According to this reference, temperature must be no greater than 145K for ice grains to be stable in hard vacuum.
http://onlinelibrary.wiley.com/doi/10.1 … x/abstract
Any free ice on the moon that is the result of condensation in surface cracks will therefore only be stable within about 3 degrees of the lunar poles, though not necessarily in permanent shadow.
Away from the poles, mixed volatiles are very likely present as gases within deep fissures. Volatiles are present in Earth magma as dissolved constituents. The moon however, is solid all the way down to the core boundary. It's mantle is solid rock almost a thousand miles deep. As the rock cooled and solidified, any dissolved volatiles would have been trapped either within crystal grains of minerals or at grain boundaries. More likely the second if crystallisation was slow. This is because any dissolved volatiles present would exert considerable stress on the crystal lattice of minerals. Over a period of G-years most of the dissolved constituents would migrate to grain boundaries due to thermal lattice vibrations and irradiation induced dislocation.
Close to the lunar surface, volatiles displaced to the grain boundaries in this way would degas into the lunar environment, as there are numerous pathways to the surface given enough time. This explains why surface material appears so dry. In the mantle, significant porosities would have opened as the rock cooled and volatiles migrating out of grain boundaries would tend to accumulate within them. We know that these exist because moon quakes resulting from internal collapses continue to this day. We could find porosities using seismographic imaging and access the relatively near surface traps by drilling.
The amount of volatiles present in a porosity would be a function of its volume and the pressure at that depth. At a depth of 40km, the boundary between mantle and crust, pressure is approximately 250MPa. So even small porosities could contain large volumes of volatile compounds, maybe even solid ice. Accessing the traps would require some very deep drilling. But on the plus side, the pressure gradient within the moon is only one sixth that of Earth. So presumably we can drill 6 times deeper using the same techniques.
Last edited by Antius (2016-11-30 06:04:18)
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Sputtering would have removed an atmosphere, but it wouldn't have removed carbonates. The Apollo drill only went to 3m depth. If there were carbonates, they would have been covered over by regolith over billions of years, so we wouldn't be able to detect them from Terra.
A fraction of any gas released by outgassing would have migrated to the polar regions and frozen out, so getting samples from those areas should tell us a lot more.
Use what is abundant and build to last
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I saw today on space daily that the Russians wanted to send a lander to bring back lunar samples. Well why has Nasa not done the same came to mind and why have we not sent a deep boring drill for those samples which we would need in order to tell if there is a store of water deep within the moon crust.
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Interesting article. Lunar fire fountains were driven by carbon monoxide gas, which comes out of magma solution at much higher pressures than other dissolved volatiles:
http://www.sci-news.com/space/science-l … 03166.html
Any trapped volatiles deep within the crust may be stored in reservoirs at pressures of 100's MPa. At those pressures, the density of trapped gases approaches that of liquid water. So a relatively small amount of porosity in the deep crust could contain large quantities of trapped volatiles. Periodic release of trapped volatiles due to fractures introduced by impact cratering, could explain the so called lunar transient phenomena. For releases a few tonnes at a time, the solar wind would remove all evidence within hours.
https://en.wikipedia.org/wiki/Transient … phenomenon
A seismographic survey using modern equipment developed for the oil industry could identify these reservoirs if they are within about 10km of the surface.
It is interesting to note, that regardless of the moons internal volatile inventory, all regolith materials are likely to be extremely dry, as volatiles not chemically bound will migrate out of grain boundaries in short geological timescales in a hard vacuum. On this basis, it is remarkable that lunar surface rocks contain any volatiles at all.
The surface rocks of the moon are also depleted in many industrial metals. On Earth, rare earth element mining typically takes place in the vicinity of impact craters. Perhaps this would be a good place to drill on the moon.
Last edited by Antius (2016-12-01 06:30:19)
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This is quite an old article, but it makes interesting reading.
http://www.osti.gov/scitech/biblio/5262838
I am not sure how well this would work. Basalt has a liquidus temperature of ~1200C, which is a bit hot for a nuclear reactor. A liquid metal cooled reactor using some sort of PRISM or pebble fuel might be capable of doing this. The magma would both corrosive and abrasive and would somehow need to be removed from the tunnels, maybe by casting into bricks in situ?
Another option is to leave the reactor on the surface and use an electrically powered melt device. The problem then is the need to trail a power cable behind the device.
All the same, this provides a good solution for lunar base construction, as it practically eliminates the need to spend large amounts of time carrying out EVA on the surface. Habitation can be subsurface from the start, shielded from hard radiation, temperatures extremes and micro-meteors.
Last edited by Antius (2016-12-01 06:46:42)
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I think for a Lunar Hotel, you might want to use glass, glass is 2.4 to 2.8 tons per cubic meter, and you need 10 meters of water to provide the same protection against cosmic rays as the Earth's atmosphere provides. I think 5 meter thick glass panes should suffice. Glass is transparent to visible light, but enough of it will still stop cosmic rays. One could make a dome that is 100 meters across out of glass that is 5 meters thick, and it would make a nice hotel that lets in sunshine, while carefully screening out the UV, x-rays, and other harmful rays. 5 meters of glass should do it. The chemical formula for glass is SiO2 and the Moon has plenty of those elements Each column of glass that is 1 meter by 1 meter by 5 meters would weigh 14 tons, which on the Moon would weigh 2.24 tons, standard air pressure at sea level is 10 tons per square meter, so a rigid frame of steel would have to hold those glass blocks in place against internal air pressure. Most of the construction material would have to be fabricated on the Moon out of local materials.
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The dome you are talking about would require 200,000 tonnes of fused silica glass and would enclose an area just under 2 acres. Do you really think this is a practical suggestion?
A slight variation on your scheme would be a dome of about the same size constructed from cast basalt blocks and then covered with regolith to a depth of 5m. This is still a major undertaking as you still need to move 200,000 tonnes of loose material onto your structure. It won’t be at all transparent either, but then again, how transparent would 5m of silica glass be? Per unit volume of habitable space it requires moving only about half as much material as excavating a habitat underground. The bigger the dome is, the more efficient in terms of moved material per cubic metre of habitable volume.
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The dome you are talking about would require 200,000 tonnes of fused silica glass and would enclose an area just under 2 acres. Do you really think this is a practical suggestion?
A slight variation on your scheme would be a dome of about the same size constructed from cast basalt blocks and then covered with regolith to a depth of 5m. This is still a major undertaking as you still need to move 200,000 tonnes of loose material onto your structure. It won’t be at all transparent either, but then again, how transparent would 5m of silica glass be? Per unit volume of habitable space it requires moving only about half as much material as excavating a habitat underground. The bigger the dome is, the more efficient in terms of moved material per cubic metre of habitable volume.
Most of that 200,000 tones would come from the Moon itself, we just need the ability to make the silica glass from the silicates on the Moon, the idea is to let natural sunlight in, and glass is transparent. How transparent is 5 meters of glass?
How transparent is air? You don't want the glass to be completely transparent, because you don't want all the harmful rays of the Sun to get through either. The Earth's atmosphere filters out some of these rays, and what's the point of being on the moon if you are surrounded by opaque walls that you can't see through when you get there?
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We would want not normal glass but something more akin to the space shuttles windows or from the ISS cupola units glass which is an aluminum based product.
So the Russian Space Agency Confirms Plans to Implement Lunar Sample-Return Mission
"Work on the lunar program, planned in the framework of the Federal Space Program for 2016-2025 years, will be implemented according to the plans. In particular, the contract for the development of the technical specification of the Luna-Grunt mission has been signed and will be implemented,"
This would be nice if they do go forth with these plans.... and hopefully Nasa would follow suit.....
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I don't think we will find life on the Moon, I think it would pay off better to send laboratories to the Moon, than to bring Moon Rocks back here! So a sample return mission, you must pick which samples to return, and upon return to Earth, you can only study those samples! But a laboratory on the Moon can study as many samples as you like. In fact we can effectively put scientists on the Moon without even sending them there! The Moon is close enough to establish a virtual presence on the moon with slow reflexes in teleoperated robots due to the light time delay., but I think AI and GPS systems are sophisticated enough, that if a scientist indicates to pick up a rock, the robot can figure out how to do that competently without direct control by the operator. I think we can build stuff on he Moon with teleoperated semiautonomous robots. You could establish a virtual labor force on the Moon by sending robots there and not worrying about how to bring them back to Earth. If a lander does not include an ascent stage, the extra mass brought to the moon instead could be a bunch of teleoperate robots an equipment. We can build a base by remote control and when we're finished, we can send humans there, this is much easier to do on the Moon than on Mars.
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A relative sent this link...
https://www.cnn.com/2023/03/27/world/wa … index.html
Water is trapped in glass beads on the moon’s surface, lunar samples show
Jackie Wattles
By Jackie Wattles, CNN
Published 4:51 PM EDT, Mon March 27, 2023The waxing crescent moon is seen from Panama City on March 25.
Luis Acosta/AFP/Getty Images
CNN
—
Trillions of pounds of water may be strewn across the moon, trapped in tiny glass beads that could have formed when asteroids struck the lunar surface, according to a new study.The findings, laid out in a study published Monday in the journal Nature Geoscience, were pieced together by scientists in China who analyzed the first lunar soil samples to be returned to Earth since the 1970s.
The research points to an answer for a question scientists have been pondering for years as they’ve attempted to pin down exactly how water is stored on the moon — especially in regions outside the lunar poles, where water ice may exist in greater abundance.
Essentially, the study fills in some gaps in a theory about a lunar water cycle.
“To sustain a water cycle at the surface of the Moon, there should be a hydrated layer (reservoir) at depth in lunar soils,” according to the study. “However, finding this water reservoir has remained elusive, despite several studies having investigated the water inventory of fine mineral grains in lunar soils.”
The authors of the latest study set out to identify a potential water reservoir by further investigating the glass beads formed during impact by asteroids. And the team found the tiny glass objects were embedded with substantial amounts of water.
A look at the study
The lunar soil sample analyzed for this study was collected by China’s Chang’e-5 mission, which made a soft landing on the moon’s Earth-facing northwest corner and carried regolith samples back home in 2020.
From those samples, researchers from several institutions in China, including Nanjing University and the Chinese Academy of Sciences, handpicked 150 grains to study, ranging in size from about 50 micrometers — or the width of a human hair — to about 1 millimeter.
The theory proposed by this latest research is that these glass beads, formed in ancient times, can be imbued with water when they’re hit with solar winds, which carry hydrogen and oxygen from the sun’s atmosphere across the solar system. In fact, it could be how more than 270 trillion kilograms (600 trillion pounds) of water is stored across the moon.
A schematic diagram depicts the lunar surface water cycle associated with impact glass beads.
Courtesy Nature
“We found a new mechanism that solar-wind hydrogen can diffuse into the glass beads and thus identified a new water reservoir on the Moon,” Hejiu Hui, one of the study’s coauthors and a researcher at Nanjing University, said via email. “On the other hand, impact glass beads are distributed in the regolith globally on the Moon. Therefore, the impact glass beads can be replenished with water on the Moon’s surface and can sustain the lunar surface water cycle.”
The beads can be replenished with water every few years, the study suggested.
The findings build on research from NASA that suggested water is present on the sunlit side of the moon. Scientists have been searching for more information about how that water was stored. (One study that was published in 2020 — which relied on data collected by NASA’s Stratospheric Observatory for Infrared Astronomy airborne telescope, or SOFIA — suggested the water detected on the moon’s surface was stored in glass.)
NASA did not immediately respond to a request for comment about this study. The space agency hasn’t been permitted to work with its Chinese counterparts since 2011, when Congress passed the Wolf Amendment.
GLASTONBURY, UNITED KINGDOM - SEPTEMBER 28: (EDITORS NOTE: Image has been converted to black and white) The moon is seen prior to the Penumbral Eclipse starting on September 28, 2015 in Somerset, England. Tonight?s supermoon - so called because it is the closest full moon to the Earth this year - is particularly rare as it coincides with a lunar eclipse, a combination that has not happened since 1982 and won?t happen again until 2033. (Photo by
Matt Cardy/Getty Images)NASA mission finds water on the sunlit surface of the moon
Understanding how water is stored on the moon is useful, Hui noted, because it could point future lunar astronauts toward potential resources that could one day be converted to drinking water or even rocket fuel.“This water can be released by just simply heating these glass beads,” Hui said.
Putting it in perspective
Dr. David Kring, a principal scientist at the Lunar and Planetary Institute in Houston, said this research gives scientists new insight into how water can be stored on the moon, particularly in locations similar to the Chang’e 5 mission’s landing spot on the nearside of the moon. He was not involved in the study.
“That’s important for scientific discussion of lunar water cycles on the moon,” he noted.
But, Kring said, there are likely better places for astronauts to harvest water for practical purposes, “which is why we’re interested in the lunar poles.”
Scientists have theorized there may be large deposits of water ice at the moon’s poles since the Apollo era. And NASA plans to send astronauts to explore the area as part of its Artemis program, which aims to send humans to the lunar south pole later this decade.
“I think the international interest in exploration of the moon will fuel everybody’s interest,” Kring said. “I cannot wait until we have Artemis astronauts in the lunar south polar region in two to three years.”
(th)
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