Magnetic anomalies on the Moon's surface

[newtons_laws]

Interesting article: https://www.space.com/mysterious-moon-swirls-resource-potential.html. Quote"
Given the science of swirls — and what we do and don't know about them — just what utility they offer for moon explorers, be it for shielding or resource-extraction purposes, is up for discussion.
Because the mini-magnetospheres above the swirls protect the surface from the solar wind and so might also protect against cosmic rays, "they might be preferential locations for future habitats," said Ian Crawford, Professor of Planetary Science and Astrobiology at Birkbeck, University of London. "
As an aside, if future Moon explorers should ever excavate at the centre of such a lunar magnetic anomaly and discover a buried monolith they should be very careful......

 

[DR.Angel]

This all sounds plausible and possible,leaving no rock over turned.But its still speculation until we actually go there to investigate.Heres another theory (or a number of them),there are many elements on the periodic table and I can imagine that there will be many more there once our race evolves over time.Do we know the effects of each and every element of what may happen in a low gravity environment full of different sources of radioactive materials coming mostly from our own sun,but what about the other stray sources coming from unknown sources.Sorry if I’m rambling so I’ll get on with it.Maybe it’s a mineral buildup that’s creating those magnetic anomaly’s,or perhaps a stew of minerals mixed to produce these anomaly’s.Or perhaps it’s decomposing minerals producing a magnetic anomaly as a byproduct of it’s decomposition,May even be the the holy grail for living in space handed to us on a silver platter just by chance.Whatever is causing the magnet anomaly cannot be answered by speculation Always have an open mind because sometimes the imagination is not always far from the true answer.

Interesting article: https://www.space.com/mysterious-moon-swirls-resource-potential.html. Quote"
Given the science of swirls — and what we do and don't know about them — just what utility they offer for moon explorers, be it for shielding or resource-extraction purposes, is up for discussion.
Because the mini-magnetospheres above the swirls protect the surface from the solar wind and so might also protect against cosmic rays, "they might be preferential locations for future habitats," said Ian Crawford, Professor of Planetary Science and Astrobiology at Birkbeck, University of London. "
As an aside, if future Moon explorers should ever excavate at the centre of such a lunar magnetic anomaly and discover a buried monolith they should be very careful......

 

[Mental Avenger]

I doubt that is relevant to "living' on the Moon. Though there may be observatories, maintenance facilities, and perhaps even mining and production on the Moon, the 14 day sizzling days and the 14 day freezing nights will not be conducive to roaming around on the surface. Domes would be targets for random meteors. "Living" on the Moon will most likely be underground.
Radiation shielding is very well understood and the necessary materials readily available. Those would be used on surface transport vehicles and surface suits. IMO, trying to make living on the surface would waste a great deal of resources with no practical uses.

 

[YetAnotherBob]

You are correct. Cheap always wins out over more expensive. A meter or so of dirt is just so much less expensive than any high tech solution. Simply dig down and build whatever you want, then bury most of it.

We will have to design for moonquakes, but that can be easily done, and they are generally rather small. Just leave some spacers before any pressure walls.

For vehicles it will be different. But there, a few inches of foam looks like it will work for NASA's new capsule. So expect the same sort of lining on your Lunar Rovers. Mcirometerorites however are harder. Dirt works there as well for bases.

 

[Mental Avenger]

Underground habitats on the Moon will have to be pressure vessels. Many years ago I did a study on this and calculated that it would take about 12 feet of Regolith on the Moon to hold down the roof of a habitat with 14.7 psi internal atmospheric pressure. IIRC.

 

[Catastrophe]

Underground habitats on the Moon will have to be pressure vessels. Many years ago I did a study on this and calculated that it would take about 12 feet of Regolith on the Moon to hold down the roof of a habitat with 14.7 psi internal atmospheric pressure. IIRC.

M A
Was this just by the mass of the regolith or did you allow some reinforcement, cementation perhaps?

 

[AlexK]

Space.com also wrote an article which may be relevant to the discussion regarding magnetic anomalies on the moon:

Weird 'Anomaly' at the Moon's South Pole May Be a Metal Asteroid's Grave

Researchers may have found the dense remains of a massive asteroid buried under the surface of the moon.

www.space.com

I know this was written in June of 2019, and wonder if any follow-up research has been done since then.

 

[Mental Avenger]

M A
Was this just by the mass of the regolith or did you allow some reinforcement, cementation perhaps?

Just the weight of the Regolith. I found the composition of the lunar Regolith and the corresponding material on Earth, and how much that weighs on Earth. Then adjusted for how much it would weigh per cubit foot on the Moon. This is all from memory of about 10-12 years ago.

 

[YetAnotherBob]

Space.com also wrote an article which may be relevant to the discussion regarding magnetic anomalies on the moon:

Weird 'Anomaly' at the Moon's South Pole May Be a Metal Asteroid's Grave

Researchers may have found the dense remains of a massive asteroid buried under the surface of the moon.

www.space.com

I know this was written in June of 2019, and wonder if any follow-up research has been done since then.

Follow up would be hard. The observation the article was based upon was from an orbiting satellite with a magnetometer. There has been no closer investigation because these things take years or even decades to plan and execute.
The best follow up would be by a ground based probe or party.

 

[YetAnotherBob]

Underground habitats on the Moon will have to be pressure vessels. Many years ago I did a study on this and calculated that it would take about 12 feet of Regolith on the Moon to hold down the roof of a habitat with 14.7 psi internal atmospheric pressure. IIRC.

That sounds about right. Most of the plans that have been published call for a more or less pure oxygen atmosphere. That requires 4 to 5 PSI. The same plans call for roughly a meter of regolith. that's about a third of what you wanted to use for three times the pressure.
If I were designing the facility, I would used steel rebar re-enforced walls with some of the microwave sintered LunaCrete that ESA is currently working with.

 

[Mental Avenger]

That sounds about right. Most of the plans that have been published call for a more or less pure oxygen atmosphere. That requires 4 to 5 PSI. The same plans call for roughly a meter of regolith. that's about a third of what you wanted to use for three times the pressure.

I don't know what plans you are referencing. We found out the hard way what pure oxygen atmosphere leads to. Command Pilot Virgil I. "Gus" Grissom, Senior Pilot Ed White, and Pilot Roger B. Chaffee paid the price for that mistake.

 

[YetAnotherBob]

Ele

Heres another theory (or a number of them),there are many elements on the periodic table and I can imagine that there will be many more there once our race evolves over time.Do we know the effects of each and every element of what may happen in a low gravity environment full of different sources of radioactive materials coming mostly from our own sun,but what about the other stray sources coming from unknown sources...

Elements are determined by the number of protons and electrons they have. We know the complete sequence from 1 right up to around 115. There are now none missing. Once there were, but they were identified. Elements any heavier than lead are unstable and therefore radioactive. Over time they decay into lead.
There are also isotopes of elements. That means there isn't a single kind of say lead or iron, but several. Those have also been charted. If you are interested, you can look at any Periodic Table and see the Element Number (which is the number of Protons and Electrons) and the isotope numbers in the Periodic Chart of the Nucleotide s. Just look it up on Google. You'll find it. Sorry, there are no missing elements below Number 117. There are some above that, but those elements last only a fraction of a second after they are formed. We hope that some higher in the so-called "Island of Stability" that is predicted for somewhere around 128 might last as long as a minute, but that isn't more than a hope.
As for the anomoly, the sources I have read believe it to be the iron core of a meterorite or asteroid impacted in a crater. Iron or steel can be magnetized by a strong shock in the presence of a magnetic field. During a collision, there is a strong flow of plasma outward from the impact point, and so a strong magnetic field is generated for a very brief time, just as it is in a fusion reactor. So far, we have no evidence for it being anything more exotic than that. Though strong local magnets created by fast collisions is actually rather exotic in my opinion.

 

[YetAnotherBob]

I don't know what plans you are referencing. We found out the hard way what pure oxygen atmosphere leads to. Command Pilot Virgil I. "Gus" Grissom, Senior Pilot Ed White, and Pilot Roger B. Chaffee paid the price for that mistake.

Flammability is the problem you are referring to. Flammability is a result of the partial pressure of Oxygen. The partial pressure of oxygen at sea level is 14.7*.25, or 3.5 PSI oxygen (to a very rough approximation). The rest is mostly nitrogen, which we generally treat as inert. We humans need more than 3 pounds of pressure, so they up it. Nitrogen isn't needed for animal life. Other inert gasses are a problem to transport. Then the systems just bring up the pressure and add things like water vapor while removing things like CO2 and methane. That's how NASA did it all for the Moon flights. Russia uses compressed air at some standard pressure. They vent to outside to maintain the pressure within acceptable levels. It's what we did with the Mercury Program too. They won't do that for longer duration missions. NASA didn't.
The problem came from using full oxygen at full sea level pressure. It was only a test, and they didn't want to pump down the capsule. And yes, a price was paid. Things that are not considered flammable burned quite fiercely in the extra oxygen. There was almost an explosion inside that Apollo capsule and three good men died uselessly.
The same thing happens in some hospitals. That's why folks in oxygen tents are isolated. Never smoke in an oxygen tent.
But at reduced pressure, there isn't so much of a problem. well, no worse a problem than we have everywhere on Earth anyway. We are never more than a large spark away from a forest fire or house fire, yet we make it through.
This is simple Engineering level Chemistry. Flammability is directly related to partial pressure of the oxidizer.
Use of nitrogen doesn't allow for low pressure unless you spend hours 'purging' the astronauts. Otherwise they may suffer from the 'Bends'. Whatever you do, there are problems unless steps are taken. So we will need to take steps.
But for the Moon, there is no problem with a low pressure near pure oxygen atmosphere. Just watch the partial pressure. You have to do that anyway to keep things livable.

 

[Catastrophe]

This all sounds plausible and possible,leaving no rock over turned.But its still speculation until we actually go there to investigate.Heres another theory (or a number of them),there are many elements on the periodic table and I can imagine that there will be many more there once our race evolves over time.Do we know the effects of each and every element of what may happen in a low gravity environment full of different sources of radioactive materials coming mostly from our own sun,but what about the other stray sources coming from unknown sources.Sorry if I’m rambling so I’ll get on with it.Maybe it’s a mineral buildup that’s creating those magnetic anomaly’s,or perhaps a stew of minerals mixed to produce these anomaly’s.Or perhaps it’s decomposing minerals producing a magnetic anomaly as a byproduct of it’s decomposition,May even be the the holy grail for living in space handed to us on a silver platter just by chance.Whatever is causing the magnet anomaly cannot be answered by speculation Always have an open mind because sometimes the imagination is not always far from the true answer.
[/QUOTE]

"Maybe it’s a mineral buildup that’s creating those magnetic anomaly’s,or perhaps a stew of minerals mixed to produce these anomaly’s"
Quite possibly iron meteorite / asteroid impact?

"there are many elements on the periodic table and I can imagine that there will be many more"
If you look at the nature of elements you can see there are few possibilities for stable elements in our part of the Universe.

"Or perhaps it’s decomposing minerals producing a magnetic anomaly as a by product of it’s decomposition"
As far as I know decomposing minerals only produce other minerals with sometimes elements, these elements have no magnetic effects except possibly between iron isotopes.

"Whatever is causing the magnet anomaly cannot be answered by speculation"
I could not agree more.

Cat