Let the Terraforming Begin! Or Not.

Most of you know me as a space lawyer, and that is indeed my day job.  I’m also a science fiction writer, and, as such, I have been trying to research how we would terraform another planet for my current novel–other than simply by showing up.  I wasn’t finding much.

I did find these lovelies: Teaming with Microbes and its equally riveting companion, Teaming with Fungi.  Although the books are directed at gardeners, they make it clear that any terraformers would need microbes as part of their arsenal.  I’ve also learned that some companies coat seeds with microbes to help them flourish, which suggests you can maybe just let them lie dormant.  We wouldn’t need to bring compost tea in its liquid form.  I’m also figuring that the microbes brought to terraform a barren rock world would be different than the ones brought as the next layer of terraforming in order for plants and animals to thrive.  The first could produce oxygen, the second could enter into symbiotic relationships with mosses, ferns, grasses, and amber waves of grain.

But, I’m just a philosophy major who likes to garden.  What do I know about terraforming?  I remained riddled with anxiety.

So imagine my delight when a couple weeks ago, Dr. David Livingstone gave me articles to read as homework for the Space Show. In the first, a microbiologist recommends exporting microbes to other planets to start terraforming.  In the second, an astrobiologist takes issue with Elon Musk not pledging himself to the principles of planetary protection.

This is what we call a policy debate.  It is a discussion not about what the law is, but about what the law should be.

Dr. Jose Lopez and his co-authors point out that as we shift from space exploration to space colonization and the possibility of a human presence in space, we need to consider certain factors, including the inevitability of a microbial presence wherever we go.  That’s because we are covered in–and full of–microbes, aka “germs or cooties.”

Lopez notes the role microbes play in making our own planet habitable, including by producing oxygen, regulating gases like carbon dioxide, methane, and nitrogen, and breaking down organic and inorganic materials:

although we highlight the importance of controlling and tracking such contaminations—to explore the existence of extraterrestrial microorganisms—we also believe that we must discuss the role of microbes as primary colonists and assets, rather than serendipitous accidents, for future plans of extraterrestrial colonization. This paradigm shift stems partly from the overwhelming evidence of microorganisms’ diverse roles in sustaining life on Earth, such as symbioses and ecosystem services (decomposition, atmosphere effects, nitrogen fixation, etc.).  Therefore, we propose a framework for new discussion based on the scientific implications of future colonization and terraforming: (i) focus on methods to track and avoid accidental delivery of Earth’s harmful microorganisms and genes to extraterrestrial areas; (ii) begin a rigorous program to develop and explore ‘Proactive Inoculation Protocols’.

Noting that the “the current planetary protection policy is not consistent with future plans to ultimately colonize space” the authors recommend rethinking current protocols:

First, obsessing about microbes in space is not practical because they are essential components of life with a majority of microbes being beneficial and nonpathogenic (Gilbert and Knight 2017). Second, it seems unnecessary, costly and futile to strive for complete sterility of every nook and cranny on all space vessels for every mission. Humans have created a ‘built environment’ which teems with microbes (Lax, Nagler and Gilbert 2015; Blaustein et al. 2019). Microbes live everywhere from the lithosphere to dust particles in the stratosphere (Smith et al. 2011). Third, assuming that launching fully sterile space vessels were possible, we still could not sterilize the human crew with their own associated microbial communities or microbiomes.

After all, NASA itself accepts that some microbes will survive current attempts to sterilize spacecraft:

Different microorganisms, mainly extremophiles and spore formers, were recovered from spacecraft surfaces and processing facilities prior to the launching of Mars spacecraft (Ghosh et al. 2010; Venkateswaran, La Duc and Horneck 2014), and the survival of some of these species like Deinococcus spp. during the interplanetary transit between Earth and Mars has been shown to be quite likely (Paulino-Lima et al. 2011; Cheptsov et al. 2017).

Is there another way?  Lopez thinks so.  And it would cost less.

It can be anticipated that savings from dropping the strict ‘no microbe’ mandate and focusing on removing only known harmful microorganisms (or their genes) could be estimated to save space projects millions of dollars.

Moreover, there has never been any rigorous follow up to determining microbial survival at the extraterrestrial sites already explored. Viable bacteria and fungi have been found on dust particles in our upper atmosphere and the International Space Station (ISS) (Smith et al. 2011), and these microbes could have already been accidentally delivered to extraterrestrial sites. Current efforts focus on characterizing microbes in the nonextreme conditions of vehicle interiors, such as the ISS (Coil et al. 2016; Lang et al. 2017), where most of the tested bacteria appeared unaffected by the space station conditions (Coil et al. 2016).

Rather than following current sterilization protocols, we should recognize that our relationship with outer space may be entering a new phase.  With humans going farther into space, we’ll be bringing all the mini-colonists who live on the surface of our skin and inside our bodies.

[T]he lack of any discovery or evidence of life from any of the past 70+ space missions and probes which have left Earth’s orbit points to only one unique presence of life in our immediate solar system.

Please notice that Lopez advocates for discussion of the issue, study, and careful selection:

Assuming that a colonization plan aims for eventual permanence, the first colonists should consist of microbial species, not human, paralleling what likely happened on primordial Earth. The paradigm shift we now advocate is that a deliberate seeding of microbes would ultimately promote colonization goals—e.g terraforming.

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We make this provocative paradigm shift suggestion based on a foundation of microbial ecology, evolution and planetary science. Biologists understand that there can be no life on Earth without the ecosystem services of various microbes (bacteria, Archaea, some fungi, algae, protozoans) (McFall-Ngai et al. 2013; Stolz 2017). The first life forms and ‘colonists’ of terrestrial Earth were not amphibians, or even plants but rather single-celled microorganisms (Pikuta, Hoover and Tang 2007). Microbial ancestors conditioned ancient Earth atmosphere billions of years ago, adding more oxygen via photosynthesis (De Marais 2000). If humanity is seriously contemplating colonizing Mars, another planet or one of the nearby moons in the future, then people need to identify, understand and send the most competitive and beneficial pioneers. Choosing or developing the most durable microbial taxa or communities may be done with deliberation, systematic research and current data, rather than sending random bacteria serendipitously hitchhiking on space stations (Coil et al. 2016; Lang et al. 2017).

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Nor do we advocate rushing microbial introductions without thorough research on Earth. Instead, we envision a deliberate and measured program of research into microbial colonization, realizing the limits of current technologies (https://mars.nasa.gov/news/8358/mars-terraforming-not-possible-using-present-day-technology/). Thus, we advocate a conservative schedule of microbial introductions into space, while also realizing that human colonization cannot be separate from microbial introductions.

We see a different perspective in Dr. Samantha Rolfe’s reaction to Elon Musk’s desire for his company SpaceX to take 100 people to Mars.  She points out that:

there is a risk that microbe-ridden humans walking on the red planet could contaminate it with bugs from Earth. And contamination may threaten alien organisms, if they exist. It may also make it impossible to figure out whether any microbes found on Mars later on are martian or terrestrial in origin.

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A mission to return samples from Mars to Earth is expected to be completed by the early 2030s, with all the collection work completed by sterilised robots. While such missions pose a certain risk of contamination too, there are rigorous protocols to help minimise the chance.

She couches her concerns as a “moral” issue.  I am not sure I understand the basis for that.  Does someone drinking kombucha create a moral issue because a microbial battle may be waged inside that person’s intestines?  As a consumer of yogurt, I certainly hope not. (I do not dispute that the safety of the space travellers might be characterized as a moral issue, but she first addresses microbes.)

Dr. Rolfe is a planetary scientist, and her own intellectual and career interests might be hampered if SpaceX were to bring Earth microbes to Mars.  But what is the alternative?  One might hope she is not suggesting the sterilization of those 100 people.  Or that her interests in finding alien microbes trumps their interest in exploring or colonizing Mars. Should life be contained to Earth?

Her concern for microscopic alien life certainly raises policy issues.  Society and lawmakers may have to decide whether the interests of colonization or science prevail.  Exploration of the dilemma may show they could even co-exist.  Co-existence seems possible, especially in light of the amount of time that explorers have had to find any life.  Mars is a big planet, and life may continue to be sought in locations far from human settlements.  I’m sure others will have even more clever solutions.