Restoring Mars’ Magnetic Field May Hold the Key to Making It Habitable
published during a waxing gibbous moon.

Mars is the next frontier for space travel. NASA hopes to send astronauts to Mars sometime in the 2030s, as does the nonprofit organization Mars One; SpaceX hopes to get crews to the Red Planet even sooner. As tricky as it is to get humans to Mars, it’s even harder to figure out a way to sustain life there. The planet lacks an atmosphere, which results in dangerous exposure to radiation, low pressure (requiring astronauts to wear pressurized suits), as well as cold, dry, windy weather. Thus, a group of scientists from the Aerospace States Association (ASA) presented a new idea at the recent Planetary Science Vision 2050 Workshop: give Mars a magnetic field.

MAVEN, the Mars Atmosphere and Volatile Evolution mission, has been gathering information about Mars’ former atmosphere and what caused it to disappear. The evidence indicates that once upon a time, Mars was a warm, wet planet, thanks to an Earth-like atmosphere. Scientists believe that solar winds shredded the planet’s atmosphere because of its magnetic field disappeared roughly 500 million years after Mars was born. Restoring that magnetic field would theoretically stop the atmosphere from leaking into space, allow for the existence of liquid water both on and below the planet’s surface, and allow for terraforming of the planet.

Such an idea has been considered before to protect astronauts either inside or outside spacecraft from cosmic radiation—the same idea would apply here, but the scale of the implementation would be far larger. Jim Green, director of the Planetary Science Division at NASA, believes it’s possible to create shields strong enough to protect the entire planet and to control the magnetic field “so that it always pushes the solar wind away.”

Restoring Mars' Magnetic Field

Artist’s rendering of solar winds stripping Mars’ atmosphere. Credit: NASA/GSFC

Using this method to induce terraforming offers distinct advantages from other strategies, including Elon Musk’s idea to detonate nuclear bombs on Mars’ poles to release the carbon dioxide stored there. If the manufactured magnetosphere could protect Mars from solar winds, then its atmosphere could replenish itself gradually, raising the temperature of the planet as well as the air pressure. Scientists believe that in a matter of years, Mars’ atmospheric pressure could be half of that on Earth. Once that happens, the planet would become warmer and the polar ice caps would melt, releasing CO2. The atmosphere would then retain that warmth, which would eventually result in liquid water on the planet’s surface.

While this approach remains theoretical at the moment, it presents exciting possibilities for humanity’s future on Mars—without nukes.