DARPA announced it is currently engineering the organisms which will terraform Mars1. For those who don’t know DARPA, it stands for Defense Advanced Research Projects Agency and it is part of the U.S. Department of Defense. Its where they came up with early versions of the internet and GPS. So my guess is that when DARPA announces something you get yourself a glimpse into a possible future where scifi has become reality.
For those who don’t know Mars, Mars is cold, with a mean temperature around -63°C and varying between 20°C at some locations at the equator during noon, and -153°C at the poles2. So Mars makes Antarctica look like a holiday destination3. And then I didn’t mention the fact yet that the atmospheric pressure at the Martian surface is very low, around 6 mbar, which is 0.6% of the 1000 mbar most of us humans live in4. This makes a really thin atmosphere. To compare, on top of Mount Everest you experience around 280 mbar5. That’s already not a very friendly pressure and most climbers use extra oxygen6. But to experience Martian pressure conditions you need to go even higher, up 35 kilometers in the sky7. Exposed to Martian conditions your saliva would boil and you would suffocate before you freeze to death8.
Another thing important to mention about Mars is that you’ve got much bigger elevation extremes than on Earth. You can go climb up 21 km and visit the summit of the massive Olympus Mons volcano, and you can go down minus 8 km to visit the lowest point on Mars in the huge Hellas impact basin9. So when you would terraform Mars and introduce lifeforms you’d probably start in the lowest regions closest to the equator where the temperature and atmospheric pressure are relatively high. This is where a batch of extremophile microbes has the biggest chance of survival.
Unfortunately, only recently through robotic missions, we discovered that the Martian surface is rather toxic for humans. The soil of Mars contains between 0.5 and 1% of perchlorates10, a type of salt, known to interfere with our thyroid11. This looks like bad news for humans12 but microbes like the perchlorates as is explained in the Space.com article: “microbes on Earth use perchlorate for an energy source. They actually live off highly oxidized chlorine, and in reducing the chlorine down to chloride, they use the energy in that transaction to power themselves.” And according to Wikipedia: “Over 40 phylogenetically and metabolically diverse microorganisms capable of growth via perchlorate reduction have been isolated since 1996 … In the process, free oxygen (O2) is generated and this is one of only a handful of biological processes to generate oxygen aside from photosynthesis.”
This brings me back to the DARPA engineered organisms. A possible first stage in terraforming is called Ecopoiesis, the “fabrication of a sustainable ecosystem on a currently lifeless, sterile planet”13. What if we could send rocket loads of engineered organisms – some type of extromophiles which like perchlorate – to Mars? Global dust storms might distribute these all over the surface. Slowly but steadily the toxic perchlorates are eaten away leaving some benevolent chemical substances and oxygen in the atmosphere.
Let’s look at these microbes more closely. On Earth perchlorate eating microbes are considered to be one of the first inhabitants of Earth. They originated billions of years ago when oxygen wasn’t present in our atmosphere yet14. Without oxygen life in those days used other ways to get around, and eating perchlorates is one of them. They didn’t die out though and are still among us. Some exist in extreme locations like in the case of Archaeoglobus fulgidus, found in a ‘black smoker’ hydrothermal vent deep in the ocean15. Others were found closer to home, like the microbe known as Dechloromonas agitata which was isolated from paper mill waste16. The latter is currently used in what is called bioremediation, a waste management technique17.
So if the first terrestrial lifeforms used perchlorates as their energy source, how about on Mars? Mars is considered by many scientists to have experienced a warmer, wetter period billions of years ago18. So if Mars was once believed to have been more like Earth, could there have been Martian perchlorate eating microbes too? Well I guess they’re not around in great numbers anymore as they didn’t touch their meal for quite a while. Although some scientists argue that Mars may still be habitable today19.
We will probably never find out if Mars was or is habitable if we choose to contaminate Mars with our own microbes. There might still be little pockets overwintering deep underground as Mars might still be, episodically, volcanically active20. So who knows? Currently the robots sent to Mars undergo a careful routine of cleaning and sterilizing21. Looking at history and current affairs though I guess its safe to say we humans tend to do things first and then think about the consequences. Will terraforming Mars be any different? Will the people arguing about this issue, discussing ethics and planetary protection, suddenly be woken up when a billionaire decides to send a rocket full of microbes to Mars? Something similar actually happened on Earth with respect to our own version of terraforming: geo-engineering. In 2012 a businessman decided to dump 100 tons of iron in the pacific ocean close to Canada22.
Talking about a billionaire. Elon Musk, from Tesla and SpaceX, wants to get humans to Mars. If Musk can retrieve the SpaceX Falcon 9 rocket first stage23 the prices to get something in space will probably go down significantly24. That’s gonna be a big disruption in the space industry. Musk mentioned earlier he doesn’t think Mars will be terraformed soon25. Maybe that was the safest thing to say, but maybe we will all be surprised? With all these exponential technologies the future might be nearer than we assume.
That brings me to the title: Guerrilla Gardening Planet Mars. Terraforming Mars with rockets full of engineered organisms to me sounds like a Godzilla version of the tree bomb dropping by Hercules planes I once read about26. I thought the same when I first read about these tree bombs, them being a Godzilla version of guerrilla gardening some of us might be doing in our neighborhoods today. Today we do guerrilla gardening, next year we might start bombing the Sahara full of trees, and within a decade we might wake up with the headline “MICROBES SUCCESSFULLY RELEASED TO MARTIAN SURFACE”.
So let’s start talking about it now. Let’s heat up the debate before we heat up Mars. Do we want Mars terraformed or keep it as it is, in its pristine state?