NASA proposes a magnetic shield to protect Mars' atmosphere

March 3, 2017 by Matt Williams, Universe Today
Artist's conception of a terraformed Mars. Credit: Ittiz/Wikimedia Commons

NASA proposes a magnetic shield to protect Mars' atmosphere

This week, NASA's Planetary Science Division (PSD) hosted a community workshop at their headquarters in Washington, DC. Known as the "Planetary Science Vision 2050 Workshop", this event ran from February 27th to March 1st, and saw scientists and researchers from all over the world descend on the capitol to attend panel discussions, presentations, and talks about the future of space exploration.

One of the more intriguing presentations took place on Wednesday, March 1st, where the exploration of Mars by human astronauts was discussed. In the course of the talk, which was titled "A Future Mars Environment for Science and Exploration", Director Jim Green discussed how deploying a could enhance Mars' atmosphere and facilitate crewed missions there in the future.

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. Over the course of the next 500 million years, Mars went from being a warmer, wetter environment to the cold, uninhabitable place we know today.

Artist’s rendering of a solar storm hitting Mars and stripping ions from the planet’s upper atmosphere. Credits: NASA/GSFC

This theory has been confirmed in recent years by orbiters like the ESA's Mars Express and NASA's Mars Atmosphere and Volatile EvolutioN Mission (MAVEN), which have been studying the Martian atmosphere since 2004 and 2014, respectively. In addition to determining that solar wind was responsible for depleting Mars' atmosphere, these probes have also been measuring the rate at which it is still being lost today.

Without this atmosphere, Mars will continue to be a cold, dry place where life cannot flourish. In addition to that, future crewed mission – which NASA hopes to mount by the 2030s – will also have to deal with some severe hazards. Foremost among these will be exposure to radiation and the danger of asphyxiation, which will pose an even greater danger to colonists (should any attempts at colonization be made).

In answer to this challenge, Dr. Jim Green – the Director of NASA's Planetary Science Division – and a panel of researchers presented an ambitious idea. In essence, they suggested that by positioning a magnetic dipole shield at the Mars L1 Lagrange Point, an artificial magnetosphere could be formed that would encompass the entire planet, thus shielding it from solar wind and radiation.

Naturally, Green and his colleagues acknowledged that the idea might sounds a bit "fanciful". However, they were quick to emphasize how new research into miniature magnetospheres (for the sake of protecting crews and spacecraft) supports this concept:

The proposed method for creating an artificial magnetic dipole at Mars’ L1 Lagrange Point. Credit: NASA/J.Green
"This new research is coming about due to the application of full plasma physics codes and laboratory experiments. In the future it is quite possible that an inflatable structure(s) can generate a magnetic dipole field at a level of perhaps 1 or 2 Tesla (or 10,000 to 20,000 Gauss) as an active shield against the solar wind."

In addition, the positioning of this magnetic shield would ensure that the two regions where most of Mars' atmosphere is lost would be shielded. In the course of the presentation, Green and the panel indicated that these the major escape channels are located, "over the northern polar cap involving higher energy ionospheric material, and 2) in the equatorial zone involving a seasonal low energy component with as much as 0.1 kg/s escape of oxygen ions."

To test this idea, the research team – which included scientists from Ames Research Center, the Goddard Space Flight Center, the University of Colorado, Princeton University, and the Rutherford Appleton Laboratory – conducted a series of simulations using their proposed artificial magnetosphere. These were run at the Coordinated Community Modeling Center (CCMC), which specializes in space weather research, to see what the net effect would be.

What they found was that a dipole field positioned at Mars L1 Lagrange Point would be able to counteract , such that Mars' atmosphere would achieve a new balance. At present, atmospheric loss on Mars is balanced to some degree by volcanic outpassing from Mars interior and crust. This contributes to a surface atmosphere that is about 6 mbar in air pressure (less than 1% that at sea level on Earth).

At one time, Mars had a magnetic field similar to Earth, which prevented its atmosphere from being stripped away. Credit: NASA

As a result, Mars atmosphere would naturally thicken over time, which lead to many new possibilities for human exploration and colonization. According to Green and his colleagues, these would include an average increase of about 4 °C (~7 °F), which would be enough to melt the carbon dioxide ice in the northern polar ice cap. This would trigger a greenhouse effect, warming the atmosphere further and causing the water ice in the polar caps to melt.

By their calculations, Green and his colleagues estimated that this could lead to 1/7th of Mars' oceans – the ones that covered it billions of years ago – to be restored. If this is beginning to sound a bit like a lecture on how to terraform Mars, it is probably because these same ideas have been raised by people who advocating that very thing. But in the meantime, these changes would facilitate human exploration between now and mid-century.

"A greatly enhanced Martian atmosphere, in both pressure and temperature, that would be enough to allow significant surface liquid water would also have a number of benefits for science and in the 2040s and beyond," said Green. "Much like Earth, an enhanced would: allow larger landed mass of equipment to the surface, shield against most cosmic and solar particle radiation, extend the ability for oxygen extraction, and provide "open air" greenhouses to exist for plant production, just to name a few."

These conditions, said Green and his colleagues, would also allow for human explorers to study the planet in much greater detail. It would also help them to determine the habitability of the planet, since many of the signs that pointed towards it being habitable in the past (i.e. liquid water) would slowly seep back into the landscape. And if this could be achieved within the space of few decades, it would certainly help pave the way for colonization.

In the meantime, Green and his colleagues plan to review the results of these simulations so they can produce a more accurate assessment of how long these projected changes would take. It also might not hurt to conduct some cost-assessments of this magnetic shield. While it might seem like something out of science fiction, it doesn't hurt to crunch the numbers!

Explore further: NASA awards launch services contract for Mars 2020 rover mission

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4.3 / 5 (6) Mar 03, 2017
Great research! Plus we never know when we here on Earth might need such a shield temporarily.
1 / 5 (1) Mar 03, 2017
Yes, I am sure if we needed to deploy a temporary shield from a extinction event solar flare, a lot of countries would object. (NOT!)
Whydening Gyre
4 / 5 (2) Mar 03, 2017
Novel idea. Wouldn't L1 be a little far away, tho?
And as far as a temp deployment of a shield to prevent an extinction level solar flare - how much warning do you think we'd have? There wouldn't be enough time to ask countries about it, much less put it on a rocket, position it and then get it powered up...
2.6 / 5 (5) Mar 03, 2017
NASA proposes a magnetic shield to protect Mars' atmosphere

In the future it is quite possible that an inflatable structure(s) can generate a magnetic dipole field

What kind of "inflatable structure" would create this field?

One last point. Where does this guy get this "unique" idea of this odd shaped magnetotail/magnetopause? Has he never seen the teardrop diagram of EM fields in space? Where in nature is this "unique" magnetotail/magnetopause observed? Me thinks these guys are modeling this with some pseudoscientific MHD models.
If you want a magnetic field to protect the planet you had better figure out a way to get the planet to generate it.
1 / 5 (1) Mar 03, 2017
prevent an extinction level solar flare - how much warning do you think we'd have?

Doesn't that depend on how far into the future(from now) it happens. Perhaps by then we will have a month or more warning.
3 / 5 (2) Mar 05, 2017
Interesting. The L1 point is, of course, a stable place to put a large magnet.

As cantdrive85 pointed out, how do you obtain this long, trailing cylindrical field when the field would be expected to form a much shorter teardrop shape?

Can we build and deploy a large enough and strong enough magnet to protect Mars from the L1 point?

As an alternate to a huge magnet at L1, could we deploy multiple smaller magnets in orbit around Mars to maintain a magnetic shield from solar radiation?
5 / 5 (3) Mar 05, 2017
Correction. The L1 point is not all that stable. We would need to provide active stabilization to maintain the magnet at that point.
1.7 / 5 (6) Mar 05, 2017
One last point. Where does this guy get this "unique" idea of this odd shaped magnetotail/magnetopause? Has he never seen the teardrop diagram of EM fields in space?

Well, it looks remarkably similar to the illustration for the Earth, here:

And then you would have to consider the field strength they are proposing of 1-2 Tesla. That is way stronger than what we see at Earth, which is measured in microtesla.
Still, the equations are on the Wiki page. Any competent plasma physicist could run them. Nobody from EU, however, due to a) lack of the suitable code, and b) lack of ability and qualifications.

5 / 5 (1) Mar 05, 2017
Pretty cool idea, but would this be particularly necessary? Mars lost its atmosphere over geologic timescales. Current losses to solar wind are basically negligible. Should we terraform and bulk up the atmosphere, solar wind losses would be greater, but it still would take hundreds of thousands to millions of years to lose appreciable mass. Radiation protection could be provided by the denser atmosphere and subsequent ozone layer. This wouldn't be quite as protective as the proposed magnetosphere, but also wouldn't require the creation of a truly massive dipole in space (think energy requirements)
1 / 5 (4) Mar 05, 2017
Well there you go, he must have gone to Wiki to do his research.
5 / 5 (1) Mar 05, 2017
Wylie played with magnets... Looked what happened!
2 / 5 (8) Mar 06, 2017
Well there you go, he must have gone to Wiki to do his research.

Err, no, I could have quoted figures from any number of scientific papers, including Alfvén's, but it was easier to just link to something more accessible. Get an education. Stop pretending that you have even clue one about plasma physics. You quite obviously haven't. All you are doing is embarrassing yourself. As usual.
Whydening Gyre
5 / 5 (1) Mar 07, 2017
prevent an extinction level solar flare - how much warning do you think we'd have?

Doesn't that depend on how far into the future(from now) it happens. Perhaps by then we will have a month or more warning.

Unfortunately, we don't have that sensing capability...
And (hate to admit it, but...) CD is sort of right. In order to maintain that 1-2 Tesla "cylinder" as shown you need to provide it consistently through out the path back to Mars...
1 / 5 (1) Mar 10, 2017
The longevity of the shield may be a problem.
An additional or alternative solution to re-starting the magnetic field and maintaining it may be to establish a deep ocean running between the poles. This might be achieved by combining existing geographic features with skidding asteroids into the surface, to provide massive earth moving and heat to melt ice to fill the created ocean.
I have long thought that the Earth's magnetic field is steered by the Atlantic conveyor. The moving ions in the salt water create a small magnetic field over a massive area from the North pole to the South, which is more than a butterfly's wing to influence the alignment of deeper fields over long periods. This would explain why magnetic reversals seem to coincide with major climate changes on Earth when the conveyor may have been changed by weather changes or tectonic drift, and why the loss of liquid water on Mars seems to coincide with the loss of its magnetic field.
not rated yet Mar 26, 2017
Even if it needs constant maintenance and resupply missions, it would be worth it to recreate a magnetosphere shield for Mars to become habitable again. This would remove the one major issue preventing serious consideration of colonizing Mars. Mars if properly colonized would have its own motivation for maintaining a space program to service the Magshield facility. It would also be a vulnerability in possible interplanetary war. Let's hope we strive to solve our social issues as well as the technical ones in future...

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