No Seriously, Elon. You Can’t Just Nuke Mars (We Asked)

By John Wenz | July 31, 2018 3:36 pm
In 1990s' Total Recall, Arnold Schwarzenegger terraformed Mars atmosphere into breathable air in mere minutes thanks to a secret alien turbinium reactor. (Credit: TriStar Pictures/Courtesy Everett Collection)

In 1990s’ Total Recall, Arnold Schwarzenegger terraformed Mars atmosphere into breathable air in mere minutes thanks to a secret alien turbinium reactor. (Credit: TriStar Pictures/Courtesy Everett Collection)

On Monday, a study published in Nature Astronomy took an exhaustive look at what it would take to terraform the Red Planet and fulfill generations of sci-fi dreams.

In it, leading Mars experts tallied the planet’s stores of carbon dioxide, a powerful greenhouse gas, and gauged the likelihood of releasing all that CO2 to create a stable atmosphere — one thick enough to have liquid water on the surface.

Their disappointing conclusion: You can’t terraform the place with any present or near future technology.

But not everyone is buying it.

SpaceX founder Elon Musk tweeted at Discover that there is a “massive amount of CO2 on Mars adsorbed into soil that’d be released upon heating. With enough energy via artificial or natural (sun) fusion, you can terraform almost any large rocky body.”

Musk is referring to carbon dioxide molecules that have stuck to the planet’s rocks over time. In the past, he’s proposed nuking the Red Planet to release these buried gases. Here, he could also be referring to using fusion as a power source that could heat Martian rocks.

So, we went back to the scientists to see what’s possible.

The astronomers said such a transformation would require technologies that aren’t here — or even anywhere near here — yet. And if we want to colonize Mars in the next few decades, we need to think in terms of what we’ll have in the next few decades. And that isn’t fusion.

“When you’re thinking about a technology far into the future, you can think about anything you like and imagine it’s feasible,” says Bruce Jakosky, head of NASA’s Mars MAVEN mission and lead author of the Nature Astronomy paper.

“That’s why we stuck with today’s technology — things we actually know how to do,” he adds.

Can’t We Though?

However, Jakosky says Elon’s not wrong in one sense: There is adsorbed carbon dioxide on the planet, as the team mentioned in their paper. But put simply, extracting it is a hard, hard process.

“On a global scale, I can only think of two possibilities,” Jakosky says of extracting the adsorbed CO2.

One of those would require producing massive amounts of greenhouse gasses on Mars’ surface. Essentially, this method would involve importing or manufacturing CFCs — usually known as ozone killing gases on Earth — and releasing the pollutants into the air to drive climate change.

The other method Jakosky suggests would mean building a mirror as large as the Red Planet’s dayside that could rapidly heat the entire globe, hopefully releasing little bits of CO2 everywhere. That’s because any localized process (like a fusion power plant) just can’t release enough carbon dioxide from the rock to make a difference.

Both of those ideas are centuries away from being even remotely possible.

And even if you did find an efficient process to extract adsorbed CO2 out of the rock — and you discovered an optimistic amount of CO2 inside all those rocks — you still wouldn’t release enough to greenhouse gases to give Mars a comparable air pressure to Earth at sea level, a unit of measurement known as a bar.

“You would still fall well short of a bar,” Jakosky says. “But you would get some significant warming and significant pressure.”

His co-author, Christopher Edwards of Northern Arizona University, says this is partly because the process of adsorption of CO2 into Martian rock isn’t as efficient as it is on Earth.

On Earth, we have carbon sinks like limestone, which store up lots of adsorbed CO2. But these are gently guided along by microbe colonies and warm temperatures. So far, the trapped carbon seen on Mars has seeped in through non-living, cold processes. And it’s spread out fairly evenly across the planet without a (known) large subsurface deposit.

“It’s really difficult to find any source of material that’s significant that can really augment the Martian atmosphere,” Edwards says.

Digging Deep

Roger Wiens, a scientist at Los Alamos National Laboratory, leads the team behind ChemCam, an instrument aboard NASA’s Curiosity rover. This instrument fires laser pulses at Martian rocks and analyzes the chemical composition of what comes out. He says that Curiosity has seen few carbonate bearing rocks at Gale Crater — the sort of calling card of adsorbed CO2.

“Carbonates are generally not that abundant on Mars,” Wiens says. “When you think about sediments on Earth, you think about carbonates because they’re everywhere.”

This is partly because Mars doesn’t have effective ways to sequester them over time.

Earth has lots of things going for it that Mars doesn’t — a magnetic field and a larger radius to help hold onto its atmosphere better. It also has plate tectonics to grab limestone, plus other carbonates to pull those down into the interior. That’s why Wiens doesn’t think we should expect to find any great reservoir of CO2 on the surface. Subduction events to bury carbon dioxide, like those seen on Earth, were likely rare and shallow on Mars.

There is one exception: There’s likely carbon from the very, very early days of Mars trapped deep, deep below the surface.

But “that’s just material that just comes out by volcanism, that’s not something that humans have access to in terms of terraforming,” Wiens says.

And while there are a few carbonate heavy areas, they seem to be localized.

Some have been seen from orbit, but only one has ever been explored by rover. The Spirit rover explored Gustav Crater from 2004 to 2010 and found a decent amount of carbonate bearing formations there.

“In these formations, they’re the dominate mineral, but these formations are relatively limited in size,” Wiens says. The Mars 2020 rover, set to launch in a year, is set to explore areas believed to have more carbonate bearing rock, probably formed in Mars’ much wetter past.

But unless Mars 2020 has an explosive revelation to share with us, terraforming proponents likely won’t catch a break.

So, for now, we might be able to explore Mars, and even set up a base in the near future. But we shouldn’t expect nuking the Red Planet to do much other than make a mess. No matter how hard you work the soil, you can’t make a lot of carbon dioxide out of only a little trapped there.

CATEGORIZED UNDER: Space & Physics, top posts
MORE ABOUT: mars, space exploration
  • Uncle Al

    Crash a C-type asteroid into Mars. Smelt local iron oxide and perchlorate into steel and carbon dioxide. The impact will be good for a few megatons to gigatons for Martian global warming.

    • Slaven
    • André Balsa

      The mass of that asteroid is insignificant compared to the amount of carbon that would be required to create an atmosphere on Mars. And the energy from the impact would be again insignificant to raise the temperature of Mars.
      Work out the math as the authors of the study did and you’ll reach the same conclusion: it’s impossible with present technology.

      • Uncle Al

        C-type asteroid 10 Hygiea, 8.67×10^19 kg
        Earth’s atmosphere masses 5.15×10^18 kg
        Lots of wiggle room..

        “Impossible” generally forks into two branches, “expensive” and “stupid.” Terraformed Mars would still be a crappy place to live, re Iceland.

        • André Balsa

          And how do you propose to accelerate a mass of “8.67×10^19 kg” so that it intercepts Mars’ orbit around the sun? Hint: rubber bands won’t do it. Again, work out the math, it’s impossible with present technology.

          The basic idea actually is that whatever means you imagine to terraform Mars, it will always be at least 1000x cheaper, faster and simpler to clean up our act and stay here on good ol’ Earth.

          • Erik Bosma

            Here, here… but the grass is always greener on the other side of the asteroid belt.

        • Victor_D

          Have you ever been to Iceland? It’s a wonderful place. In many ways it already looks like what early terraformed Mars could be like.

    • Erik Bosma

      Don’t forget the meteorite storm we could set off. Get your lead umbrellas…

  • Bob Jarvis

    Hey, maybe we should listen to Elon Musk. He’s an amateur with a bunch of money, so *obviously* he knows more than people who have spent their lives studying these issues. Because, y’know, we’ve found that hiring pseudo-rich-guy amateurs to do important stuff has just worked out *SO* well, don’tcha think?

    • Elminster

      I must wonder- why is the current president the first thing that comes to mind, when I read this?

    • Elminster

      I really must wonder- why the current president is the first thing that comes to mind, when I read your comment?

      • okiejoe

        I just thought that too. We have an excellent example of what happens when we turn the running of something over to a know-nothing BECAUSE he’s a know-nothing.

    • Erik Arne Hansen

      Jeez. And he happens to own and run a rocket company filled with scientists.

    • Bill Skywalkerr

      This amateur happens to be an FRS, also the chief designer of the most advanced rocket company on the planet of Earth.

      Another amateur with a total of two year’s worth of education, was elected an FRS about 250 years ago. That fellow’s name was Benjamin Franklin.

  • Saul Causano

    They really gloss over the lack of a magnetic field and 1/3 of Earth’s gravity. It doesn’t matter how much co2 is on the planet if the solar wind is just going to strip it away again. Mars had an atmosphere at one point and now it’s gone and it’s not coming back.

    • frigjord

      That’s a very slow process(millions of years).The lack of a magnetic field isn’t really a big issue.

      • André Balsa

        “The lack of a magnetic field isn’t really a big issue.”
        Wrong. Earth’s magnetic field makes DNA possible. The lack of magnetic field on Mars makes it a dead planet.

        • frigjord

          Earths atmosphere is enough to protect us from radiation.

          • André Balsa


          • frigjord

            No, you are wrong. During geomagnetic reversal the magnetic field is very weak without being linked to any mass extinction. for example:
            “A brief complete reversal, known as the Laschamp event, occurred only 41,000 years ago during the last glacial period. That reversal lasted only about 440 years with the actual change of polarity lasting around 250 years. During this change the strength of the magnetic field weakened to 5% of its present strength.”

      • Marcelo Meireles

        There are ways to create an artificial magnetic shield for Mars, which doesn’t make it logical to waste so much effort on another planet when our own is in need.

        • frigjord

          There is enough money in the world to do booth. It’s not like the money would go to the needs of planet Earh anyways.

        • okiejoe

          Just install a small black hole at the center of Mars. Bingo! Plenty of mass and magnetic field. Now, if we could only keep it from dragging Jupiter into itself.

  • Jens Nielsen

    When someone with subject knowledge says it can’t be done it usually pays to listen, but how often have we heard “experts” tell Musk that his plans were infeasible? Stop assuming he’s just a dreamer and hear him out properly, you might just learn something new.

    • okiejoe

      “Infeasible” doesn’t mean impossible, it just means it’s a waste of time and money and asteroids. If we just keep on burning coal and oil we will have plenty of CO2 right here to warm up Mars.

  • SuperTroll

    Fortunately he can’t run for President. At least only if they change the Constitution.

  • Marcelo Meireles

    To colonize another planet is a sci-fi idea. There’s no sound logic in that yet. On the other hand, It’s imperative that we focus those great resources on saving the Earth from ourselves.

  • Edgar9999

    Earth has a magnetic field. Mars’ field is orders of magnitude weaker. Solar wind will strip any atmosphere we care to generate.


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