Is Terraforming Mars & Venus Actually Possible?

Terraforming Mars and even Venus may be possible, says a four-decade veteran of NASA. In fact, the former director of the agency’s planetary science division says he is working on just such a plan that would employ a giant magnetic shield to help each of those planets to start terraforming themselves. And it is a plan he says is doable.


For decades, planetary scientists and science fiction writers alike have toyed with the idea of making a planet other than Earth habitable for humans, a process more commonly known as terraforming. Due to its size and rocky composition, Mars is the most common target for such theories, with the much hotter yet mostly earth-sized Venus also making the occasional appearance.

Now, recently retired, forty-plus year NASA veteran Jim Green sat down with the New York Times for a long ranging interview about this terraforming concept, the overall search for extraterrestrial life and the upcoming Europa Clipper mission.


“Our solar system is 4.5 billion years old, and at this time, Earth is covered in life,” Green told the Times. “But if we go back a billion years, we would find that Venus was a blue planet. It had a significant ocean. It might actually have had life, and a lot of it. If we go back another billion years, Mars was a blue planet. We know now Mars lost its magnetic field, the water started evaporating and Mars basically went stagnant about 3.5 billion years ago.”

The Debrief recently reported on another proposal to help Mars regain a magnetic field to help protect potential colonists from harmful solar radiation. But unlike that plan, which involves enlisting one of the Martian moons to do the trick, Green’s concept involves placing a giant magnetic shield in orbit that would prevent solar radiation from stripping away the Martian atmosphere, while simultaneously raising the temperature on the red planet’s surface to more habitable levels.

“Stop the stripping, and the pressure is going to increase. Mars is going to start terraforming itself,” said Green. “That’s what we want: the planet to participate in this any way it can. When the pressure goes up, the temperature goes up.”

Green says that with enough time, the pressure of the atmosphere could cross a magic threshold where humans can survive on the surface without protection.

“The first level of terraforming is at 60 millibars, a factor of 10 from where we are now. That’s called the Armstrong limit, where your blood doesn’t boil if you walked out on the surface,” said Green. “If you didn’t need a spacesuit, you could have much more flexibility and mobility. The higher temperature and pressure enable you to begin the process of growing plants in the soils.”

According to the lifelong planetary sciences expert, there are several different scenarios to implementing his magnetic shield. In fact, he is in the process of writing a paper on the topic, a paper he says may not be well received by his colleagues.

“The planetary community does not like the idea of terraforming anything,” said Green.


In this same interview, Green talks about the upcoming Europa Clipper mission, which will look at Jupiter’s moon Europa for signs of life, a goal he has been championing for most of his career.

“The plumes on Europa are what made the Europa mission happen. I was at an American Geophysical Union meeting in 2013. Several of the scientists were going to give a talk on finding a plume with Hubble on Europa, and I go, “Oh, my God.” I said this is fantastic, I want to do a press conference. I call back to NASA headquarters, and they pulled it off. I took that information back with me to headquarters and added that into the story of Europa. That really turned the corner. They said, “Wow, maybe we should do this.””

Finally, Green addresses the ongoing search for signs of life on Mars dating back to the Viking lander missions of the 1970s, while offering his own thoughts about the hunt for life in the clouds of Venus, a planet he also thinks would make for a great terraforming target.

“I think we can change Venus, too, with a physical shield that reflects light,” said Green. “We create a shield, and the whole temperature starts going down.”

Follow and connect with author Christopher Plain on Twitter: @plain_fiction