Build moon magnetosphere?

[kelvin_zero]

The idea of building something the scale of a magnetosphere sounds ridiculous but is it? This link on mini magnetospheric plasma propulsion http://en.wikipedia.org/wiki/Mini-magnetospheric_plasma_propulsion suggests that in vacuum even a very lightweight object can create a significant magnetosphere from a small carried supply of gas, so what could a hefty version on the moon's surface produce?

The intended benifit is to reduce the amount of radiation shielding required for moon habitats. Also, to what degree could a magnetosphere affect the moon's ability to retain atmosphere?

Of course there would have to be careful consideration of how it would interact with the earth's magnetic field also. I think some animals use a magnetic sense for navigation. Worse, perhaps it could interfere with the van-allen belt or turn the earth into a microwave oven. Still.. shouldnt dwell on the negatives..

[MeteorWayne]

I think you are VASTLY understimating the scale of what you are proposing.

But the Krell forgot one thing John. Monsters. Monsters from the Id. 

I really, really, really, really miss the "first unread post" function 

[thereiwas]

I wonder if a magnetic field strong enough to do that would be harmful to the occupants?

How about putting a moon base in a big crater at the poles, not only to take advantage of possible ice there but to be shielded from the sun most of the time by crater walls. This is assuming that the source of the dangerous radiation is the sun.

[kelvin_zero]

MeteorWayne
I think you are VASTLY understimating the scale of what you are proposing.

Me: Yeah.. was slightly drunk. sorry. Probably should have put this in FreeSpace. Was just taking statements from some of those links that implied a field could easily be made to grow to vast proportions with very little power. Didnt really have anything quantitative at all. In my defense, I didnt specify this was an initial strategy, or just something to try after exponential growth of industry has converted the moon, say in a century.

In the short term there isnt even much value in protecting a large area anyway.

CAN anyone put any quantitative numbers to this?

Hi ThereIWas: Yeah I was wondering if the poles are a good location for that reason. It would be great if shielding, a peak of eternal light, and water were all at the same location.

[kelvinzero]

Hey, could someone check my maths for me? My calculator skills are a bit rusty.

Im trying to put some figures to the scale. First step is to estimate the sort of current required to create a magnetic field equivalent to the earth's, over a similar volume.
My model will be: suppose I produce a current around the earth's equator, how large must it be to reproduce the magnetic field strength at the earth's pole?
(very simplified of course, but only want rough answer)

The formula for magnetic field of a circular loop is:

Bx = (u*I*a^2) / (2*(x^2 + a^2)^(3/2))

where u=4*Pi*10^(-7) (units: T.A^-1.m)
Bx = desired magnetic field = 60 microtesla (ie 60*10^-6 T)
a= radius of loop (for which we are choosing radius of earth, r=6.3*10^6m)
x= distance from loop to reach pole (also r)

since x=a (=r, radius of earth), we can simplify the equation if we like. I get:

I= ( Bx*2^(5/2)*r )/u

This seems to work out to 1.7*10^9 A, ie about a billion amps. (I dont care about the .7 since my model is so simplistic. For starters we could have chosen the moons radius if we liked)

anyone enthusiastic enough to check that?

[spacester]

I can confirm your algebra, IOW

Bx = (u*I*a^2) / (2*(x^2 + a^2)^(3/2))

is the same equation as

I= ( Bx*2^(5/2)*r )/u

where x = a = r

I'm no math genius, I just take it one step at a time:

Bx = (u*I*a^2) / (2*(x^2 + a^2)^(3/2))
Bx = (u*I*x^2) / (2*(2*x^2)^(3/2))
Bx = (u*I*x^2) / (2*(2^3/2)*x^3)
Bx = (u*I) / (2*(2^3/2)*x)
Bx * x * 2*(2^3/2) = (u*I)
Bx * x * 2*(2^3/2) / u = I
I = Bx * x * 2*(2^3/2) / u
I = Bx * x * (2^2/2)*(2^3/2) / u
I = Bx * x *(2^5/2) / u
I = Bx * r *(2^5/2) / u

I don't have enough info to check the units or the applicability of the equation in the first place, but it looks reasonable, with no glaring errors.

Can we adapt this formula to apply to a horizontal loop, i.e. a loop laying on the lunar surface, surrounding an encampment? We would be interested in the field strength in the direction perpendicular to the surface, not the radial direction as given here.

[kelvinzero]

Thanks!

Yeah Im dubious about the model myself. Im actually guessing it is a significant over estimate of what would be required for the moon since (a) I used the earths radius, (b) my model duplicates the poles field, but probably creates a massively higher one at the equator? (wheras on earth it is actually halved)

Im guessing you would want an arch rather than a loop. Charged particles can get past the earths magnetic field at the poles (creating aurora effect) even though the field is stronger there because charged particles are only deflected by moving perpendicular to the field. (ie right hand rule: thumb is direction of proton movement, fingers are direction of magnetic field, palm is direction of force.. I think)

The cool part is that you dont need to actually construct this arch. the current can be carried by a plasma loop in vaccum.

This link talks about making loops with 20km radius in vacuum: http://news.bbc.co.uk/2/hi/science/nature/6567709.stm

[nexium]

Using super conductors, the billion amps could be maintained long term with less than 1000 watts, I think, but buldup from zero to a billion amps would take gigawatt hours, I think, so we would not want to start over each evening on the moon = twice per month.
My guess is a billion amp plasma loop 20,000 kilometers long would require a gigawatt continiously. I just read the link, which does not imply that the plasma loop would produce the magnetic field, so my guess is the super conductors are the only option and super conductors would need to be drained of their energy every sunrise on the moon, to avoid distructon of the super conductors as they got hot. Neil

[kelvinzero]

I dont know how to estimate the loses. They might be pretty low. certainly when people discuss using it for magnetic sails they imply power usage and particle losses are small.

[webtaz99]

Plasma conducts current. A loop of plasma conducting current will generate a magnetic field.

[docm]

And Earths field is only ~60 microteslas (0.6 gauss) at the surface. The magnetic field at the surface of the Sun is about 10^-4 tesla.

[kelvinzero]

I think I read 60 microteslas at the pole, 30 at equator, so that would be your fountain effect. Perhaps if magnetic fields are generated by a current through the van allen belt then magnetic field strengh at earths surface does not tell us anything.

.. but I suspect it really is a very weak field, just over a very large volume and this is enough to deflect charged particles.

[keshe]

My be there is a simpler way to create magnetosphere on the moon or on any other planet.

There is a possibility that soon systems will be developed that can create magnetic fields that are combination fields.
What this means, is that the passengers of the craft will have a constant magnetosphere protection with a given gravitational field force internally in the system.

Where the system creates a second magnetic field to stand the magnetosphere forces of the planet, this being moon or others, independent of the internal conditions.

In the past month, the first patent application for system which can produce magnetosphere like planets has been published by the European patent office.

Now the final development and testing of the system is to be done most probably in China.

[kelvinzero]

Sorry I didnt really understand. Do you have a link?

[keshe]

If you do not understand, let me explain it in a simple way.

Where ever there is a magnetosphere in the universe there is always gravitational field force.

Therefore these two forces are interconnected.

What has changed the game in the space technology, is that now through understanding of the inner geological structure of the earth from earthquakes data's around the world in the past 25 years, and constructing a reactor which is a copy of the earth inner cores working, a new space technology has emerged and has been developed.

This new data’s have shown that earth maintains three cores in its inner sanctum instead of up to now presumed two, of the inner core and the outer core.

Consequently the planet posses two independently created and operating irrespective of the other magnetic fields, separated by the known solid inner core of the earth, against the presumed one magnetic filed up to now, where the field was consideared to be just due convection between the inner core and the outer core and the motion of the inner core.

Where the interaction of these two magnetic fields in a plasmatic state up on each other creates the magnetosphere fields of the planet and the gravitational forces of the planet at the same time too.

As these two separately developed magnetic fields on either side of the partition can not interlock, as they are in a plasmatic condition and not solid magnet, their individual strength can be manipulated, thus allowing to create varieties of magnetosphere strength and gravitational field strength, within the same system.


What this allows a system to achieve , is that you can maintain the magnetosphere for protection and extend or reduce its domain and its strength, but at the same time you are allowed to change the gravitation field strength of the system to change too, thus allowing, for example if the system is used in craft, for the craft to position itself in

[webtaz99]

Let me be the first to say:

Whiskey Tango Foxtrot, over?

[keshe]

Yes exactly

Do not forget People who are working on the M2P2 project of the Washington university for NASA , where this thread was started on , are on the near the same principal line of research as was explained above through magnetic plasma and combination and interaction field of the forces.

[Paulson]

Mr Keshe is a total fraud. Please ignore everything he has said. HIs so called technology has not been proven. I read through his book and its total garbage. What he claims is new science is basically bloody pseudoscience. I will eat my hat if he successfully demonstrates his bright lights in sky on television. He won't so I will never believe him. If you are not mental you will not believe him.

[EarthlingX]

Here is a thread with some links to information about electro magnetic plasma shielding and such:
Cloaking tech for cosmic radiation protection ?

Lunar Shields: Radiation Protection for Moon-Based Astronauts

Most practical solution for protecting Lunar habitats would probably be to go underground, but until then, there will probably be localized solutions like above examples.

Permanent solution would be to restart Moon's core, if it is enough metallic to create a magnetic field. It could probably be done with big enough asteroid, perhaps of a same mass ratio as Moon is to Earth.

[MeteorWayne]

Restarting the Moon's core to create a dymamo is impossible. First, there isn't enough iron. Even a huge asteroids would not add enough. In any case the moon is too small to retain the heat long enough. That is also why Mar's core is frozen; it's just too small a planet, and Mars is much bigger than the moon.

And in case you are going to suggest we heat it up to the melting point of iron, the amount of enrgy required to do that would be far more than would be required to shield the moon in a surface generated field.