NASA proposes magnetic shield to make Mars habitable

The shield could protect explorers and restore some of the planet's water

A NASA scientist has presented the idea of launching a giant magnetic shield around Mars in order to restore its atmosphere and potentially make the Red Planet habitable in the future.

Speaking at the Planetary Science Vision 2050 Workshop at NASA headquarters in Washington, DC, one scientist proposed the enticing idea of launching a "magnetic shield" to a stable orbit between Mars and the sun, called Mars L1, that could shield the planet from high-energy solar particles.

The workshop was meant to discuss ambitious space projects that could be implemented, or at least started, by 2050, and would see ideas supporting the next phase of Solar System exploration.

In a talk titled, "A Future Mars Environment for Science and Exploration,"Jim Green, NASA's Planetary Science Division Director said how although Mars today is an arid and cold world with a very thin atmosphere and frozen water resources, it's thought that the planet could once have had deep, liquid oceans and a warmer (and potentially habitable) climate.

Restoring Mars's atmosphere

When Mars lost its protective magnetosphere billions of years ago, solar-winds - high-energy particles projected from the sun - began stripping away an estimated 90% of the planet's atmosphere .

The shield structure would consist of a large dipole, which is a closed electric circuit powerful enough to generate an artificial magnetic field, Popular Mechanics reports, and would serve as a replacement for Mars' magnetosphere, allowing for the restoration of its atmosphere.


A diagram of a magnetic shield to protect Mars from bombardment by solar particles. Credit: NASA/Jim Green

Green said how launching the shield in the space between Mars and the sun could hypothetically shield the Red Planet in the extended magnetotail that trails behind the protective field, as seen in the above diagram.

Admitting that the idea sounds "fanciful", Green pointed to emerging research revealing that a miniature magnetosphere can be used to protect humans and spacecraft from cosmic radiation, with his team believing there is no reason why the it should not work on a larger scale with Mars.

"The solar system is ours"

With protection from solar winds, frozen CO2 at Mars's polar ice caps would start to turn directly into gas from a solid. The resulting greenhouse effect would start to fill Mars's thin atmosphere and heat the planet,  at which point the vast stores of ice under the poles would melt and flood the planet with liquid water.

“This is not terraforming as you may think of it where we actually artificially change the climate but we let nature do it, and we do that based on the physics we know today,” Green said.

“This tells us that perhaps we don’t have all the physics in the model we need. We have a little more work in this area.”

In the NASA team's simulation models, the magnetic shield could help Mars achieve half the atmospheric pressure of Earth in a matter of years, and although it is a purely hypothetical idea at the moment, the researchers plan to continue their studies in modeling Mars’s climate to look at radiative effects of ice clouds and trace gases.

"The solar system is ours, let's take it. That of course includes Mars and for humans to be able to explore Mars, together, with us doing science, we need a better environment," Jim Green said at the talk. 

He added that "if this can be achieved in a lifetime, the colonisation of Mars would not be far away."