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NASA proposes a magnetic shield to protect Mars' atmosphere
- inlineint 10y agoIt is unclear what kind of technology are they planning to use for this shield. If it is usual electromagnets, it's unclear where would they take energy from, if superconducting ones than it's unclear that it would be possible to keep them in superconducting state for long. Wish someone more knowledgable about this kind of tech comment on this.
- adrianN 10y agoSolar works okay on Mars. I don't think the power requirements for keeping your liquid helium liquid is not so great.
- 3JPLW 10y agoDefinitely superconductors; that's the only viable way to generate a field that strong. Design the spacecraft properly and you may not need an active cooling system. The James Webb Space Telescope aims to keep the shaded side below 50K… while at the same time solar panels and all its solar-facing equipment will operate 250K hotter near room temperature. The trick is maintaining this temperature gradient. Apparently the design of the JWST is sufficient to reach temperatures as low as 37K on the cold side passively — below the superconducting limit for some materials. They're additionally using a cryocooler to take the temp down to below 7K for one specific instrument. https://jwst.nasa.gov/cryocooler.html https://jwst.nasa.gov/cryocooler.html
- rhave 10y agoThe article and paper lacks any indication of the amount of energy needed to run such a magnetic field. What amount would it take to run it, and what sources of energy would be viable for it?
- deleted 10y ago[deleted]
- ChuckMcM 10y agoPresumably PV panels. Although a really large RTG (nuclear thermal reactor) might work too. It really depends on the amount of power we're talking about.
- awful 10y agoResearch NMR magnets the size of several refrigerators already exceed 8-10T; they are superconducting and could after initial run up likely run for years with no power at all. They drift down over time but it likely not be a show stopper, and the cold of space would help them minimize cryogen maintenance times - it would be an activity on the way to or from the planet maybe? Edit: though the magnet itself wouldn't require continuous power, others added there would be pressure from the sun and say it could be counteracted by orbit geometry or active force being added.
- mighty_atomic_c 10y agoSo you thave ouched on an important limitation of electromagnets; they need to be cooled. In space, the vacuum surrounding this power hungry object would be inferior to air for heat transfer; heat merely seeps out slowly radiatively. So there would be a major improvement in keeping heat low/improving system efficiency or to transfer heat away without cooking the crew after the turn the thing on.
- deleted 10y ago[deleted]
- awful 10y agoIm not sure of your context; but yes an electromagnet is a non-starter here from the get go; dealing with all the mass and power issues, bad spacey thermodynamics.
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- jasonme 10y agoYou hated Trump that much huh
- dang 10y agoPlease don't do this here.
- IndianAstronaut 10y agoI am curious why we don't focus more efforts on Titan, which already has a thick nitrogen atmosphere.
- notaplumber 10y agoIt's very far away from the Sun.
- chris_va 10y agoPlus Jupiter has a pretty intense magnetosphere that Titan transits. Jovian space has a lot of self generated radiation that makes it less than hospitable. Edit: Titan is a moon of Saturn. Oops.
- ythn 10y agoPretty sure everywhere but earth is going to be extremely inhospitable
- manojlds 10y agoAnd us?
- notaplumber 10y agoStill very far away from the Sun, but closer.
- cjensen 10y agoJupiter is 5.2 times farther from the Sun than the Earth. Thanks to the inverse square law, it gets 3.7% of the sunlight that Earth does. You won't be growing any plants there, and solar electric is going to be terrible. Saturn, which Titan orbits, is 9.6 times farther, and receives 1% of the sunlight that Earth receives. Mars is much better at 1.5 times farther, and receiving 44% of the sunlight that Earth does. Also, Titan averages -179C compared to Mars' range from -125C up to 20C.
- superkuh 10y agoUnfortunately this will not work. That isn't to say that the construction, placement, and powering of an artificial magnetosphere at Mars-Sun L1 is infeasible. It can totally be done with today's tech and modest meter scale superconducting rings. Mini-Magnetospheric Plasma Propulsion (M2P2): High Speed Propulsion Sailing the Solar Wind (http://earthweb.ess.washington.edu/space/M2P2/STAIF2000.PDF http://earthweb.ess.washington.edu/space/M2P2/STAIF2000.PDF) probably represents the core concept. Except instead of trying to go somewhere you stay where you are. The M2P2 paper says a 10cm diameter superconducting coil can divert solar wind in a bubble up to 20 km in diameter. It wouldn't take too much to scale that up. Of course diverting that much solar wind would create a force on the object. In the paper above that force is used to accelerate a craft. It'd be some handful of newtons at 20 km and linearly more to do what this project wants. One way you might get around that is to "lean into" the wind by going down the sun-side of the L1 halo orbit and allowing the force from the diverted solar wind to counter the sun's gravity's acceleration. But for the vast majority of the lost Mar's atmosphere the kinetic energy needed to achieve escape velocity is not from impact with solar wind ions or other solar wind related/magnetic field means. All those hereafter referenced under the umbrella term "jeans escape". Instead the majority of the kinetic energy needed comes from the ejected electrons from the sun's light ionizing the upper atmosphere. That ejected electron has quite a bit and it is distributed to the ions it later interacts with and as those ions interact with others. If there was no solar wind at all the rate of atmospheric loss at Mars would drop but not significantly if the sun still shone upon it. That isn't to say that, having no magnetosphere, Mars (or Venus) does not lose an additional small amount of it's atmosphere to jeans escape mechanisms. But that amount is limited due to the currents created in the upper atmosphere by photoionization creating their own local magnetic field. That creates a bow shock about the ionopause which slows the incoming solar wind down such that it's constituent ions no longer have the energy needed to deliver the boost required for escape. And because of the induced magnetic field other solar wind magnetic field based mechanisms which would pick-up the ions ionized by the sun's light are mitigated. I love the idea of this but it isn't going to make Mars have a decent atmospheric pressure in just some years. On a (much) lighter note, I was thinking if you put these artificial magnetospheres all over the inner system and then coordinated turning them on and off you could "paint" the termination shock surface of the heliosphere with different scales of tubulence in charge density. It'd be a multi-hundred AU wide screen visible only from very far away with sensitive polarimeters (detecting the changes in lines of sight charge density through faraday rotation). Might be a decent way to METI since it'd not require much energy or high angular resolution at the other end. tldr: It's technically and economically feasible. But it doesn't work like suggested for atmospheric protection because almost all the mass loss is from light caused photoionization, not the solar wind (and other Jeans escape mechanisms).
- thatcherc 10y agoThis is incredibly exciting but a few important details are missing. The first is how big does the structure need to be? I can buy a 1 Tesla magnet online right now but that's probably not what they're thinking of. Would we need a city-sized coil or something like that? The second is the time scale. They say that the temperature could rise by 4 Celsius and trigger a greenhouse effect, but is that an immediate effect (10 years or so) or century-scale effect? I'm hoping the scientists put out a paper because I'd love to learn more about the specifics of their proposal.
- SideburnsOfDoom 10y ago> is that an immediate effect (10 years or so) or century-scale effect? We should be so lucky. Planetary scale can be rather large and slow. For instance the oxygenation of the Earth's atmosphere took hundreds of millions of years https://en.wikipedia.org/wiki/Great_Oxygenation_Event#Time_lag_theory https://en.wikipedia.org/wiki/Great_Oxygenation_Event#Time_l...
- im3w1l 10y agoWe have managed to warm the earth considerably in less then a century and that's without trying. I reckon if we gave it our best we could change planetary scale things even faster than that.
- SideburnsOfDoom 10y ago> in less then a century The industrial revolution has been going since before 1800 https://en.wikipedia.org/wiki/Industrial_Revolution https://en.wikipedia.org/wiki/Industrial_Revolution
- simonh 10y agoThat was a byproduct of economically useful work though. If you can think of economically useful work that this project could generate, on an ongoing basis while it's in progress, that's greater than it's ongoing costs that would be great.
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- JoBrad 10y agoI believe this is the workshop referenced, and they do have a LiveStream that you can watch. http://www.hou.usra.edu/meetings/V2050/ http://www.hou.usra.edu/meetings/V2050/
- superkuh 10y agoSkip to 1:36:00 for the start, 1:40:00 for the actual details.
- thatcherc 10y agoThe live stream I found only went up to 1:20:00 or so - is there a longer one?
- superkuh 10y agohttps://livestream.com/viewnow/vision2050/videos/150701155 https://livestream.com/viewnow/vision2050/videos/150701155 There's also this very short pdf release which has no interesting detail. http://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf http://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf
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- spraak 10y agoWhy not a shield for earth, when this atmosphere is clearly in need of help, and already much closer to liveable than Mars'?
- deleted 10y ago[deleted]
- saagarjha 10y agoBecause Earth already has a magnetic field.
- throwawayish 10y agoOk, but what about having a S.H.I.E.L.D. for earth? Wouldn't that work?
- fudged71 10y agoFor now yes. We are overdue for a magnetic field reversal so this would be a very helpful tool in our planets arsenal
- saagarjha 10y agoYes, but is a reversal really a bad thing? Magnetic field reversals don't seem to be a serious threat–there's no evidence of mass extinctions caused by them.
- pcmaffey 10y agoCurious why Mars and not the Earth's moon, seems to be the prime target for colonization?
- deleted 10y ago[deleted]
- wyager 10y agoMars has atmosphere (not much, but enough to process into useful gases), water (in the form of ice), and a larger variety of surface materials than the moon. Mars is substantially easier to establish a long-term operation on than the moon since you can create many of the materials you need onsite.
- jcoffland 10y agoMars also has more gravity than the moon.
- VLM 10y agoAn interesting theme in KSR's mars trilogy was robot miner machines making a mohole pit and "a couple KM down" the martian atmosphere is either sea level earth air pressure or at a somewhat different depth the atmosphere is comfy warm. I don't remember the modeling of how deep or how far apart but it didn't seem terribly unrealistic compared to the grand scheme of teraforming mars. Obviously a thickened atmosphere would not require moholes quite as deep. Possibly to a useful level. True, increasing surface pressure on mars by a factor of ten means you'll still die on the surface, but to a first approximation you just made your mohole 1/10th as deep and 1/10th the construction time and cost. The atmosphere on Mars is actually pretty nice at an altitude of negative a couple kilometers, which doesn't exist naturally but we're quite talented at building horizontal tunnels that long so pointing downward can't be that hard. If you need raw material, robots that never leave the mine don't have scalability problems that human deep mines have and on mars liquid water would be a valuable commodity and robots don't mind water anyway, and solar powered robots can be left alone to generate iron ingots for construction, and for environmental reasons there's no reason to make 100 shallow pits when one deep mine produces just as much and is valuable real estate after digging is complete. On the earth you can't point a large TBM downward because it'll flood or overheat in just a couple miles or less, but on mars it might be quite useful. The problem with moholes is eventually you end up with the submarine problem where no matter how tough your metal hole liner is in an abstract sense, it will collapse under rock pressures. So you can't bore a hole clean thru a planet, however interesting that idea sounds. (edited to add, I looked up data more recent than KSRs old book series, looks like bare rock mines are only possible on mars due to rock blowing out to a depth of 10 KM (better than earth, lower gravity), of course the sky's the limit with steel liners. And at a mere 5 deg/km temp increase on mars, the temp will be cold but more habitable than the surface)
- novaleaf 10y agoWeaponization? A variation put into the Earth-Sun L1 and used to direct focused steams of solar particles onto an earthward target....
- Symmetry 10y agoThat won't work without shutting down Earth's magnetic field.
- VLM 10y agowhich it does on a regular basis during natural field reversals. The geologists imply its a very sharp transition like a century or less from normal field, no field, reversed field. If you donate to the UN fund that pays for the solar shield, you get shielded when the time comes. If not, well... life does survive reversals, but its likely not fun.
- bbcbasic 10y ago> If you donate to the UN fund that pays for the solar shield You jest, but look at the difficulty of countries agreeing on carbon pricing. Which is a similar prisoners dilemma
- saagarjha 10y agoActually, it appears that that the field does not actually disappear completely during the switch.
- marcofloriano 10y agoBest idea I've seen in years on space solutions, specially at colonization. No marketing bullshit, just plain science. And it may be the first practical step on terraform a planet before we try to colonize it. "While it might seem like something out of science fiction, it doesn't hurt to crunch the numbers!" Now we need those numbers.
- hwillis 10y agoI don't know the specifics of solar radiation well enough to say how much power the deflection would require, but there is an easy order of magnitude calculation to figure out how much energy setting up a field that size would require. It's not the same as consumption but it's a start. The energy in a uniform field is very simple to calculate: a sphere with a radius of 6371 km (radius of earth, diameter of mars) and 50,000 nT would store about a 10^18 joules, about 6.5% of US annual electricity consumption. At the extremal 500,000 nT that would be 10^20 joules, around 2x the global electricity consumption. A dipole field would require ~10x more energy, a zetajoule. That's around 2x the global human annual energy consumption, including for heat/transport/industry/etc.
- Pica_soO 10y agoCould this be reduced, by putting the shield further out?
- hwillis 10y agoNo, the Martian Lagrangian point L1 is the only stable point that can be used. If you tried to move the blocker closer to the sun, the device would have to orbit faster than Mars. L1 is the point where the gravity of the sun and Mars cancel out. The only other place you could have it would be directly on mars, where it would have to be much larger.
- Already__Taken 10y agoCan you use the solar power collector as light sail to nudge the orbit closer to the sun-side of L1. I would assume every km would help.
- therein 10y agoThat actually might make it require more energy.
- Retric 10y agoI don't think this is a uniform field, also this is at L1 so it could likely be much weaker than earths magnetic field and still work. For comparison earths magnetic field is 31,000 nanoTesla and they are putting it at L1 so a weaker/smaller field to do the same job.
- JumpCrisscross 10y agoIs there a good entry-level article or video explaining planetary magnetics? I'm an aerospace engineer and I struggle with the difference between magnetospheres, magnetotails, magnetosheaths, magnetopauses and Magneto's psychological struggles.
- azernik 10y agoX-men comics will provide you with an intro-level understanding of at least one of those.
- make3 10y agomagnetopause sounds like a bad menopause pun
- Rhinobird 10y agoMagneto goes through "the change"
- avar 10y agoAs another layman I find the Wikipedia article on the subject to be really good: https://en.wikipedia.org/wiki/Magnetosphere#Structure https://en.wikipedia.org/wiki/Magnetosphere#Structure There's nothing inherently different about a planet's magnetic field pushing the stellar/solar wind out of its way and e.g. a boat on water pushing water out of the way. Terms like magneto(sheath|pause|tail) are just labels for different parts of the "wake".
- fsloth 10y ago"There's nothing inherently different " Yes there is. Magnetohydrodynamics are more complex than hydrodynamics because of the electromagnetic effects. https://en.wikipedia.org/wiki/Magnetohydrodynamics https://en.wikipedia.org/wiki/Magnetohydrodynamics Yes, there is the fluid component, but in addition to that, there are the bits coming from electromagnetics. Arising from Maxwell's "a moving charge creates a magnetic field..." and "a force is induced on a charge moving through a magnetic field "etc.
- benp84 10y ago"can generate a magnetic dipole field at a level of perhaps 1 or 2 Tesla (or 10,000 to 20,000 Gauss)" I'm just amused by this conversion. Who is this for? Are there people who know one unit of magnetic flux and not the other?
- chki 10y agoIt is probably for the "non-scientific" reader who thinks "1 Tesla seems very low to me, that's not really impressive. Now 10.000 Gauss: I can imagine that to be pretty ... much"
- doubleunplussed 10y agoI'm not sure, but everyone in atomic physics talks gauss for some reason.
- M_Grey 10y agoWell think about it... 1 Tesla = 10,000 Gauss. When you're talking about magnetic fields in MRI coils, or planetary magnetosphere it helps to use a larger scale. When you're talking about EM forces on the scale on an atomic nucleus though, it's more helpful to speak in terms of Gauss.
- zild3d 10y agoBut that is why we have metric prefixes, different scales call for the appropriate prefix. Magnetic field of a neutron star ~1MT, magnetic field of a human brain ~1pT
- M_Grey 10y agoSure, but when you actually have to do math with them, and use them every day in practical language, it starts to make a lot less sense. After all, the goal of terms of art isn't to make the language of a given pursuit less opaque to "outsiders", but to facilitate work within the pursuit.
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- Houshalter 10y agoInstead of terraforming, would it be possible to build a giant glass ceiling over most of the surface? Humans don't really need an entire atmosphere, just a few hundred feet of it. This is still infeasible now, but it seems much easier than terraforming. With robotic labor and automation, it may not even be that expensive.
- xchaotic 10y agoSo let me get this straight - science can't currently beat flipping a coin in terms of predicting the weather more than 2 days in advance, but he can accurately simulate space weather for many years and how it will affect other planets?
- leothekim 10y agoThere is weather, and there is climate. The latter we have very good models for, the former is notoriously difficult to predict. https://www.nasa.gov/mission_pages/noaa-n/climate/climate_weather.html https://www.nasa.gov/mission_pages/noaa-n/climate/climate_we...
- prewett 10y agoI'm not convinced that we have a good model for climate, either. I think we do not have any clue about large-scale cycles in the climate. Nobody predicted the long drought in California, but the Southwest has had a bunch of cyclical droughts over the past 1000 years. This year was supposed to be a La Nina year for California, but instead something else happened and there has been three years' worth of rain in northern California instead.
- Kubuxu 10y agoWe don't need to simulate the weather, we just need to know the long running average and deviations to estimate how much of that we need to block. Short time of high activity won't blow the atmosphere off. This is the difference between weather and climate. I can't tell you what will be precise weather in one year, but I can tell you that January will be probably cold.
- Meerax 10y agoWould a distributed constellation of satellites at L1 work? A bunch of smaller magnetic dipole umbrellas working together.. Easier to repair and replace individual satellites without having the whole system go down.
- peg_leg 10y agoCool, let's build the Death Star there.
- bleair 10y agoDoes building a magnetosphere for the purposes of protection require an atmosphere, or is it all about capturing and shaping solar wind? If it doesn't require an atmosphere, could this approach be used to build a magnetospher around the moon? It feels like colonizing the moon first is a much easier and more useful problem to tackle. Once we have a moon colony you can crack water to make fuel and then go "where ever" you'd like - other asteroids, or mars. The moon is much closer and easier to get to, though maybe people need the "excitement" that travel to Mars connotates.
- Armisael16 10y agoWhere does the water come from?
- criddell 10y agoThere's more than a trillion pounds of water ice on the moon.
- Armisael16 10y agoMixed in with rock at low concentrations. Are you proposing shipping massive mining machines to the Moon?
- criddell 10y agoThis is a thread about building a magnetic shield to protect an entire planet. Shipping some gear to the poles of the moon to melt ice doesn't seem that crazy in comparison.
- PaulHoule 10y agoMars has a lot of water, it is just solid.
- brianberns 10y agoIIUC, the proposal is to build a magnetic shield at a stable Lagrange point between Mars and the sun. Mars would be far away, in the "shade" created by the shield. So there's no magnetosphere around Mars. It's more like a magneto-cylinder. :) This image explains it better than I can: https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/2017/1-nasaproposes.jpg https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/2017... I don't think an approach like this would work for the moon, because there's no stable Lagrange point between the moon and the sun. (And even if we did build a magnetic shield for the moon somehow, I think it's still too small to accumulate an atmosphere.)
- n1000 10y ago> The current scientific consensus is that, like Earth, Mars once had a magnetic field that protected its atmosphere. Roughly 4.2 billion years ago, this planet's magnetic field suddenly disappeared, which caused Mars' atmosphere to slowly be lost to space. What kind of event could cause the loss of a planet's magnetic field?
- hvs 10y agoIt once had a liquid core (like Earth) which generated the magnetic field. Being a smaller planet, it cooled faster and now the core is solid, hence no more magnetic field.
- lutusp 10y ago> What kind of event could cause the loss of a planet's magnetic field? Planetary magnetic fields require a liquid ferrous mantle or core. As Mars cooled, its liquid ferrous material solidified, after which its magnetic field disappeared. The same thing will eventually happen here, and the reason our field still exists is because Earth is a larger planet than Mars, requiring more time to cool down. More details here: http://arachnoid.com/restoring_mars http://arachnoid.com/restoring_mars
- psandersen 10y agoWould something like this be viable as part of a geoengineering solution to climate change? E.g. could we partially cancel out earth's magnetic field in order to control atmosphere loss and thereby control the greenhouse gas effect?
- cstejerean 10y agoMaybe that's a viable solution but to me controlling green house gases by shedding our atmosphere sounds like a terrible idea. I'm pretty sure we would want to keep the oxygen around. Finding ways to capture CO2 from the atmosphere and sequester the carbon should hopefully also be easier than controlling the magnetic field of the earth.
- lutusp 10y agoI think losing our atmosphere to control the greenhouse effect would be ... a very bad idea. It would work, but we would end up wishing we hadn't done it.
- ganfortran 10y agoGood luck they have that money.
- visarga 10y ago> NASA proposes a magnetic shield to protect Mars' atmosphere That's officially called a "deflector", anyone who's seen Star Trek knows.
- lutusp 10y agoIt's a nice idea, and it's one I proposed some years ago: http://arachnoid.com/restoring_mars http://arachnoid.com/restoring_mars
- jlebrech 10y agohow about just moving there an polluting the atmosphere as a side-product of just being there?
- faragon 10y agoAnd what about an artificial moon instead?
- gexla 10y agoI think the science fiction movie "Spaceballs" was head of its time. Planet Druidia had an enclosure to protect its oxygen, but Lord Helmet tried to suck it out with MegaMaid. NASA might have to think about how to counter such threats, possibly from a future and more hostile Earth civilization. https://www.youtube.com/watch?v=lTSWdHY9Ny4 https://www.youtube.com/watch?v=lTSWdHY9Ny4
- gexla 10y agoThis could lead to life elsewhere in the galaxy to protest climate change on Mars. We might get visitors if we try messing up a second planet.
- CodeSheikh 10y ago"As a result, Mars atmosphere would naturally thicken over time, which lead to many new possibilities for human exploration and colonization.." How long would it take though?
- _archon_ 10y agoThat depends on how involved humanity is in cultivating that atmosphere. There have been proposals to, for example, redirect comets/near-Mars objects that are icy/have oxygen or other desirable materials to burn up in the Martian atmosphere, adding to it. There are likely other ways we can affect the atmosphere. From a terraforming standpoint, a viable, long-term magnetosphere is necessary in the medium and long term. In the short term, humans would be stuck in shielded suits and indoors, both to protect from radiation and to ensure a breathable atmosphere.
- yaks_hairbrush 10y agoHere's a thought: Could we put one of these at the L1 point of the Earth-Sun system to protect against solar storms? If something like the Carrington Event happened to our current society, it would be absolutely devastating. Bonus: Could we make it big enough to encompass the moon?
- allemagne 10y agoWould doing this reduce or eliminate northern lights? That would be a little sad.