# How would we get Mars' core going again?



## Dennis E. Taylor (Jan 4, 2015)

This came up tangentially in one of the other Mars-related threads, and it's been preying on my mind. Assuming that Mars has at least _some_ metallic core, but it's all frozen, what technology would have at least a theoretical chance of firing it up again? I've thought about the following:

- Drilling a bunch of tunnels and dropping in some large nuclear (or maybe anti-matter) bombs
- Some kind of reactor or some such to provide heat at a more steady rate
- big, and I mean BIG solar mirrors, pointing straight down the poles.
- A very very VERY large rotating electromagnet at the poles, to try an melt the core through some form of inductive heating.
- Start dropping planet-busting asteroids onto Mars on an ongoing basis. This one seems a little drastic...

Other ideas? I don't think any extant Mars-colonization novels have dealt with this.


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## Dave (Jan 4, 2015)

What? Do you mean to tell me there is no ancient native alien-built Oxygen machine on Mars inside glacial caves that Arnie can't just turn on? Maybe it was all just a free form delusion from a schizoid embolism after all?


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## BAYLOR (Jan 4, 2015)

Nuclear devices might do the trick for Mars core .


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## Vertigo (Jan 4, 2015)

Describing Mars' core as 'frozen' is very misleading. It is thought to be fluid just as ours is and it's temperature is in the region of 1500K. Actually only our outer core is fluid the inner core is solid even though it is thought to be around the same temperature as the surface of the sun. I believe, and I'm no expert, that the activity in our core is more to do with the violent convection currents in the outer core whilst Mars' is more(?) dormant.

Bottom line is that we don't have anything big enough to effect a planetary core and I don't think there is even any speculative science that might do so. Maybe if you could get a something really big like one of Jupiter's moon to crash into it might do it but you'd likely have to wait a few million years for it to cool down again.

I believe current theories suggest it is quite possible that Mars' core could 'start up' again of its own accord. However as I mentioned in the other thread it is now thought that the magnetic field has much much less impact on protection from radiation than had been thought. So I'm not quite sure why we would want to 'restart it'. What it needs is a load of atmosphere.


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## BAYLOR (Jan 4, 2015)

Vertigo said:


> Describing Mars' core as 'frozen' is very misleading. It is thought to be fluid just as ours is and it's temperature is in the region of 1500K. Actually only our outer core is fluid the inner core is solid even though it is thought to be around the same temperature as the surface of the sun. I believe, and I'm no expert, that the activity in our core is more to do with the violent convection currents in the outer core whilst Mars' is more(?) dormant.
> 
> Bottom line is that we don't have anything big enough to effect a planetary core and I don't think there is even any speculative science that might do so. Maybe if you could get a something really big like one of Jupiter's moon to crash into it might do it but you'd likely have to wait a few million years for it to cool down again.
> 
> I believe current theories suggest it is quite possible that Mars' core could 'start up' again of its own accord. However as I mentioned in the other thread it is now thought that the magnetic field has much much less impact on protection from radiation than had been thought. So I'm not quite sure why we would want to 'restart it'. What it needs is a load of atmosphere.




If not the magnetic field , then what is the mechanism that keeps the atmosphere from being eroded by the solar winds?

If mars had an atmosphere the same density as earth, It would be habitable, at least at the equatorial zone and it would allow liquid water to exit on the surface.


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## Dennis E. Taylor (Jan 4, 2015)

Vertigo said:


> Describing Mars' core as 'frozen' is very misleading. It is thought to be fluid just as ours is and it's temperature is in the region of 1500K. Actually only our outer core is fluid the inner core is solid even though it is thought to be around the same temperature as the surface of the sun. I believe, and I'm no expert, that the activity in our core is more to do with the violent convection currents in the outer core whilst Mars' is more(?) dormant.



http://beamartian.jpl.nasa.gov/towhnall/question/186/does-mars-have-a-molten-core

Hmm, NASA disagrees with you, although they aren't making any definitive statements. And current theories seem to indicate specifically that the lack of atmosphere is due to lack of protection from a magnetic field.

In any case, even if the core is still partly molten, it just shortens the time frame and simplifies things a bit, it doesn't really invalidate the question.


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## Vertigo (Jan 4, 2015)

Well I don't want to get into link battles but:

Wiki has it that it is liquid: http://en.wikipedia.org/wiki/Mars
New Scientist has "It has been known since 2003 that at least part of Mars' interior is molten, based on how easily the Sun's gravity distorts the planet's shape, but no one knew whether it is completely liquid, or whether there is a solid inner core like Earth's." http://www.newscientist.com/article...ates-mars-has-a-molten-core.html#.VKmBxmdyZhE

Of course there is no way we can know either way for certain. But my point was that simply heating it up is not necessarily going to start it up and that heating up such a vast amount of matter would be an extraordinary endeavour and finally that it probably wouldn't achieve very much. I mean why do you want to 'start it up" again?


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## Dave (Jan 4, 2015)

Bizmuth said:


> Hmm, NASA disagrees with you, although they aren't making any definitive statements. And current theories seem to indicate specifically that the lack of atmosphere is due to lack of protection from a magnetic field.


Unless there has been some recent research I've missed, all of these theories are simply abstract postulating without any empirical backing. Which means there is plenty of room for wild speculations and science fiction.

We don't even know why the Earth's core flips magnetic polarity every so often. That could be due to factors external to the Earth, or it could be due to processes within the core. We have only scratched the surface of the Crust with decades-long drilling experiments.


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## Vertigo (Jan 4, 2015)

BAYLOR said:


> If not the magnetic field , then what is the mechanism that keeps the atmosphere from being eroded by the solar winds?
> 
> If mars had an atmosphere the same density as earth, It would be habitable, at least at the equatorial zone and it would allow liquid water to exit on the surface.



This is what I read on wiki here http://en.wikipedia.org/wiki/Atmospheric_escape


> Depending on planet size and atmospheric composition, however, a lack of magnetic field does not determine the fate of a planet's atmosphere. Venus, for instance, has no powerful magnetic field. Its close proximity to the Sun also increases the speed and number of particles, and would presumably cause the atmosphere to be stripped almost entirely, much like that of Mars. Despite this, the atmosphere of Venus is two orders of magnitudes denser than Earth's.[3] Recent models indicate that stripping by solar wind accounts for less than 1/3 of total non-thermal loss processes.[3]
> 
> While Venus and Mars have no magnetosphere to protect the atmosphere from solar winds, photoionizing radiation (sunlight) and the interaction of the solar wind with the atmosphere of the planets causes ionization of the uppermost part of the atmosphere. This ionized region in turn induces magnetic moments that deflect solar winds much like a magnetic field.



Now of course I know that Wiki is not the word of God but what it says makes sense and they also comment:



> A common erroneous belief is that the primary non-thermal escape mechanism is atmospheric stripping by a solar wind in the absence of a magnetosphere.



As you say what Mars needs is an atmosphere. Give it that (bombard with comets or some such) and even if it is still losing atmosphere it would be fine for several millions of years. Atmosphere loss is a _slow_ process.

The major problem, in my opinion, is radiation and an atmosphere would do a lot to improve that; probably more than a magnetosphere.


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## Vertigo (Jan 4, 2015)

Dave said:


> Unless there has been some recent research I've missed, all of these theories are simply abstract postulating without any empirical backing. Which means there is plenty of room for wild speculations and science fiction.
> 
> We don't even know why the Earth's core flips magnetic polarity every so often. That could be due to factors external to the Earth, or it could be due to processes within the core. We have only scratched the surface of the Crust with decades-long drilling experiments.


I agree and that, I suspect, is why it is so easy to fine contrary views on the web. The real point IMO is whether it is actually of any importance.


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## BAYLOR (Jan 4, 2015)

Mars lacks a large moon instead has two very small moons, So  how does it's Axis maintain stability?


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## Dennis E. Taylor (Jan 4, 2015)

Well, fair enough. But what a link-war really proves is that the question doesn't have a definitive answer. As to why you'd want a magnetic field, there are several potential benefits. One is the atmosphere-stripping issue-- and it's worth noting that this isn't an all-or-nothing question. The Venus example is a bit of a red herring, because Venus is also much larger than mars, _and_ has an atmosphere consisting mostly of heavier gases. So it's not unreasonable to postulate that a smaller world like Mars would be more subject to atmospheric stripping in the absence of a protective field.

The second issue is ozone breakdown. The ozone layer is what protects us from UV, and even if we dumped a full atmosphere on Mars through some advanced technology, the lack of a field would mean no ozone layer.

Then there's the question of the solar wind simply reaching the ground without a field. That would affect biology somewhat, but would affect electronics more.

And of course, the magnetic field isn't the only consequence of an active core. Tectonic activity would also be increased. We'd prefer plate tectonics of course, instead of Venus' periodic resurfacing, but anything is better than nothing.

I think what I'm driving at is that "terraforming" Mars may consist of more than just adding air and water.


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## tinkerdan (Jan 4, 2015)

My understanding is that there are still some who believe that life as we know it would not exist without the present core and the magnetosphere. In part that is because of protection by deflection of cosmic rays and that if we were to go beyond the magnetosphere the cosmic rays would bombard us with no protection so we would need to shield ourselves.

If we were to want to make mars habitable closely to the way earth is then yes the magnetosphere might be helpful.

Once we work this technology out we could always turn off ours and see what happens just to be sure we aren't wasting time and resources.


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## BAYLOR (Jan 4, 2015)

tinkerdan said:


> My understanding is that there are still some who believe that life as we know it would not exist without the present core and the magnetosphere. In part that is because of protection by deflection of cosmic rays and that if we were to go beyond the magnetosphere the cosmic rays would bombard us with no protection so we would need to shield ourselves.
> 
> If we were to want to make mars habitable closely to the way earth is then yes the magnetosphere might be helpful.
> 
> Once we work this technology out we could always turn off ours and see what happens just to be sure we aren't wasting time and resources.




Short of trying to jumpstart the core is there any other way to generate a magnetic field sufficient to protect Mars Atmosphere?  Perhaps we can come up a technology solution here?


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## Mirannan (Jan 4, 2015)

BAYLOR said:


> Mars lacks a large moon instead has two very small moons, So  how does it's Axis maintain stability?



Quite simply, it doesn't - obliquity ranges from 0 degrees to 60, most astronomers believe. Most of the way down this page: https://en.wikipedia.org/wiki/Axial_tilt


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## ralphkern (Jan 5, 2015)

BAYLOR said:


> Short of trying to jumpstart the core is there any other way to generate a magnetic field sufficient to protect Mars Atmosphere?  Perhaps we can come up a technology solution here?



Circling the planet with cabling and running electricity through it? I suspect so much power would be required that it might be easier, looking at the raw numbers just to jump start the core again, but in terms of the engineering involved, could be far simpler.

I haven't even done back of the fag packet calcs, so more than happy to stand corrected.


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## tinkerdan (Jan 5, 2015)

I think for the answer we need a magnetics expert. If someone can find one let me know. I recently needed specific information about strength and the field of a rare earth magnet we have custom made from a magnetic manufacturer and they couldn't answer the simple questions.

I did manage to find this small piece of some interest.
http://www.ti.com/lit/ml/slup123/slup123.pdf


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## BAYLOR (Jan 26, 2015)

tinkerdan said:


> I think for the answer we need a magnetics expert. If someone can find one let me know. I recently needed specific information about strength and the field of a rare earth magnet we have custom made from a magnetic manufacturer and they couldn't answer the simple questions.
> 
> I did manage to find this small piece of some interest.
> http://www.ti.com/lit/ml/slup123/slup123.pdf




Duplicating a magnetic field of the required magnitude is a bit beyond our current technology and manufacturing capability.


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## ralphkern (Jan 26, 2015)

Ha, ya think?


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## BAYLOR (Jan 26, 2015)

ralphkern said:


> Ha, ya think?



If possible, it would be quite feat of science , engineering and technology.  Id love to see it done.


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## Mirannan (Jan 26, 2015)

tinkerdan said:


> I think for the answer we need a magnetics expert. If someone can find one let me know. I recently needed specific information about strength and the field of a rare earth magnet we have custom made from a magnetic manufacturer and they couldn't answer the simple questions.
> 
> I did manage to find this small piece of some interest.
> http://www.ti.com/lit/ml/slup123/slup123.pdf



I'm not sure anything about the magnetic properties of rare earth alloys would be relevant to this discussion anyway. The reason is that permanent ferromagnetism (the sort we see in magnets) is dependent on the temperature of the magnet (or lump of metal you want to be a magnet) being below a certain point called the Curie point which is different for each alloy.

Planetary cores, including that of Mars, are big lumps of nickel-iron alloy. The temperature of even Mars's core is almost certainly well above the Curie point of this material. For reference, the Curie point of iron is 1043 K and that of nickel is 627 K. (Isn't Wikipedia great?  )

Planetary magnetism is caused by a dynamic process, namely currents in the liquid part of the core caused by the rotation of the planet. The precise mechanism of this causation is unknown AFAIK. For Earth, the liquid is iron; for Jupiter and Saturn it is liquid metallic hydrogen. Mars has a weak residual field, probably generated by such materials as magnetite (Fe3O4) in its crust.

So to give Mars a significant magnetic field, one would need to re-melt the core. The energy required for this would be astronomical - literally. And getting the heat to the core without completely devastating the surface of Mars would be a problem, too.

Incidentally, Venus has very little magnetism for a different reason. Venus is almost the same size as Earth, and probably has a core about the same size too. But its rotation is so slow that the currents to generate the magnetic field just haven't formed. So to give Venus a magnetic field would involve spinning it up. Also astronomical in scale.


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## BAYLOR (Jan 26, 2015)

Mirannan said:


> Incidentally, Venus has very little magnetism for a different reason. Venus is almost the same size as Earth, and probably has a core about the same size too. But its rotation is so slow that the currents to generate the magnetic field just haven't formed. So to give Venus a magnetic field would involve spinning it up. Also astronomical in scale.




In the case of Venus , theytheorize that the every 500 million years, the planet heats up turns itself completely inside out.


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## Mirannan (Jan 26, 2015)

BAYLOR said:


> In the case of Venus , theytheorize that the every 500 million years, the planet heats up turns itself completely inside out.



Yup. There are three speculative reasons for the Earth/Venus difference I've heard; of course they could all be operating. The first is that Earth's tectonic plate system crucially depends on fairly large amounts of water in material being subducted, which essentially lubricates the crustal motions involved. Venus, of course, has virtually no water. The second is that Venus's almost complete lack of rotation alters crustal dynamics compared to Earth. And the last is that tidal flexing of Earth's crust makes a difference. (This is also connected to Earth's fast rotation.)

None of this alters the matter of whether Venus's core has a liquid component. I don't know how this could be found out; the internal structure of Earth was discovered by seismometry, and dropping seismometers on Venus (that last more than a few minutes, anyway) is challenging to say the least!

But a liquid core doesn't help unless it is circulating.


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## Ray McCarthy (Jan 26, 2015)

Perhaps we should pick an easier project than Mars. Anyone fancy any Real Estate on any of Jupiter's Moons?


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## BAYLOR (Jan 26, 2015)

Ray McCarthy said:


> Perhaps we should pick an easier project than Mars. Anyone fancy any Real Estate on any of Jupiter's Moons?



 Europa Gardens.


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## Mirannan (Jan 26, 2015)

BAYLOR said:


> Europa Gardens.




Bit of a problem with Europa if you want to terraform it. The problem being that if you raised it to Earthlike temperatures it wouldn't have a solid surface. That's apart from the nuclear-reactor levels of radiation...


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## BAYLOR (Jan 26, 2015)

Mirannan said:


> Bit of a problem with Europa if you want to terraform it. The problem being that if you raised it to Earthlike temperatures it wouldn't have a solid surface. That's apart from the nuclear-reactor levels of radiation...



I though Europa had a solid surface. They have theorized that we might possibly find life on Europa given that there are oceans of water there beneath the ice.


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## tinkerdan (Jan 26, 2015)

What I was referencing was::


Mirannan said:


> I'm not sure anything about the magnetic properties of rare earth alloys would be relevant to this discussion anyway. The reason is that permanent ferromagnetism (the sort we see in magnets) is dependent on the temperature of the magnet (or lump of metal you want to be a magnet) being below a certain point called the Curie point which is different for each alloy.


:: the notion that magnetism just like gravity is a big unknown and that I wouldn't rule out that you could position platforms on space to generate magnetic fields that would create the desired effect of simulating a magnetosphere, but that would probably be about the same time we figure out how gravity works and then that would change everything anyway.


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## Mirannan (Jan 27, 2015)

BAYLOR said:


> I though Europa had a solid surface. They have theorized that we might possibly find life on Europa given that there are oceans of water there beneath the ice.



Yup. Europa's surface is solid. Solid ice, which means that terraforming Europa would melt the ice. Incidentally, the ocean is thought to be 100km or so deep so planting colonies on the sea floor is also out of the question barring some serious advances in materials science.


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## BAYLOR (Jan 27, 2015)

What we need to do is find the planet Mangrathea . Let them install a new core in Mars, It would be maintenance free for long time.


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## BAYLOR (Sep 28, 2016)

Mars had a larger moon , that might provide the gravity to heat up Mars's Core.


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## Vertigo (Sep 28, 2016)

I don't think that would be enough. I think you would have to have a 'moon' that is significantly larger than Mars to get this effect. In other words instead of moving a moon to Mars I think you'd have to move Mars to Jupiter.

As far as I know the Earth's core temperature is comes mostly from decaying radioactive isotopes; a process that will eventually die down and Earth will cool. However I think the timescale for this is comparable to that for the expansion of the Sun so I suspect it is probably not something Gaia need worry too much about!


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## Mirannan (Sep 28, 2016)

Vertigo said:


> I don't think that would be enough. I think you would have to have a 'moon' that is significantly larger than Mars to get this effect. In other words instead of moving a moon to Mars I think you'd have to move Mars to Jupiter.
> 
> As far as I know the Earth's core temperature is comes mostly from decaying radioactive isotopes; a process that will eventually die down and Earth will cool. However I think the timescale for this is comparable to that for the expansion of the Sun so I suspect it is probably not something Gaia need worry too much about!



AFAIK there is a fairly big contribution from phase changes at the core/mantle boundary and also at the inner/outer core boundary, both of which release heat.


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## Vertigo (Sep 28, 2016)

I'm sure you probably know more on this than myself @Mirannan  so you're probably right. Either way I don't think the gravitational effects of a larger moon would cut it. Ultimately to be thinking of doing something like this I suspect means we're trying to figure ways of fighting entropy.


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