Earlier this year, a research team made waves by suggesting that we should disseminate Earth’s microbes on Mars in a preemptive effort to foster a climate hospitable to human life. To the “anti-contamination” school of celestial thought, this was heresy; to the most others, this was an obscure theoretical squabble over an issue they’d never heard about. Still, given that our descendants may well spend their most productive years on Mars, it’s worth trying to grasp these early, pre-colonial debates before they assume life-or-death urgency. To that end, for this week’s Giz Asks we’ve posed a two-parter to a number of relevant experts. First: Could we populate another planet with genetically modified organisms? Second: Should we?
Associate Professor, Anthropology, York University, whose research focuses on the social and ethical aspects of space exploration, among other things
We probably could; we probably shouldn’t. But first, it’s worth asking: who’s “we”?
Discussion of space and the future often involves a rhetorical “we” that encompasses “all humanity” or “our species.” But it’s time to think differently about space. There is no big “we” here. For the foreseeable future, only a very few human beings will have the capability to launch or act in space—and only a very few human beings have the ability to genetically modify other organisms. And obviously, that tiny contingent of humans invents and develops these technologies with the general intention of using them.
That tiny contingent of humans does not include me. I have opinions. But I don’t have a vote. And that’s true for the vast majority of people reading this. That matters, because when a space agency, space advocacy group, Elon Musk, or Jeff Bezos, etc., says “We should do X or Y in space”… they’re using traditional rhetoric that encourages audiences to think that we (the rest of humanity) are a part of what they’re doing. Clarity on this matters a lot now, as multilateralism is either faltering or collapsing, the capabilities of private actors are accelerating, and the likelihood of unilateral actions increases. There are a multitude of different interests in space, and a multitude of ideologies and capabilities—not one “we.”
Anyway, in theory, yes, some humans could introduce some genetically modified organisms onto another planet. (Full-on terraforming is much less feasible.) Not all planets would be suitable, but some might be. Human technology cannot yet physically reach the myriad planets outside our solar system, but miniscule interstellar probes carrying dormant microbial payloads and pointed at exoplanets are theoretically possible. But for the moment, the most likely targets would be the planets (and moons) in our own solar system. So:
Should some humans populate a world in our solar system with GM organisms? Nooooooooo. At the very least, not yet. Reason #1: many would regard this as a breach of the Outer Space Treaty. Reason #2: some of those worlds might have life already, and it’s much better to find it and study it thoroughly first. Reason #3: Perhaps other worlds have their own intrinsic value regardless of their liveliness. Worth considering, at least.
Further away: should some humans populate an exoplanet with GM organisms? A louder “Noooooooooooooo.” Louder because there’s an unnerving asymmetry: it could be faster/easier to send a payload-laden micro-probe to an exoplanet than to study the exoplanet thoroughly first. Also, human beings are not going to exoplanets anytime soon—if ever—which negates a main justification for doing this kind of bioengineering.
Senior Scientist, SETI Institute
Take Mars, Europa, and Enceladus—each of which appear to have water tucked out of the way, below thick ice layers (although not always hidden—there are plumes). We probably could modify an Earth organism, or suite of organisms, to live in such places for some limited period of time, but I couldn’t guarantee you could “populate” one of those places with GMOs. Unless you were tremendously lucky, the Earth organisms might eat all of the minerals in reach, and then stage a massive die-off that would be tremendously yucky and pointless. And if you were that lucky, there might be native organisms that would just eat your GMO additions and yield a polite “burp” of methane and leave it at that. Right now we don’t know enough to do something useful with GMOs at any alien place (and only a few on Earth).
There are lots of ways in which we are too ignorant to do anything useful with this scheme, and of course not knowing how ignorant we are is one of them. We do not need to give up on a search for life elsewhere in this solar system just because some microbiologists have a tool and no patience. And we don’t need to take shortcuts in pursuing such a search so that we lose that scientific pursuit just because it is hard to do without inadvertent (let alone purposeful) contamination of the best sites.
Professor of Planetary Habitability and Astrobiology at Technical University Berlin, President of the German Astrobiology Society, and Co-author of The Cosmic Zoo: Complex Life on Many Worlds
I don’t think we’re there yet, in two senses. We don’t know the environmental conditions of other planets well enough, and we don’t know how to optimally tune the genetic code of an organism to thrive in that extraterrestrial environment. The only planet where I see this as a possibility in the near future is Mars, which we know best of all the planets and moons in our Solar System.
But even if we can do it, I don’t think we should. It would be a very human-centric approach. Instead, we should try to explore the diversity of life that may exist on other planetary targets. In regard to Mars, that would mean exploring whether indigenous (microbial) life exists, and if so, studying how it is different from life on Earth. (Even if there is a common origin, evolution in the different planetary environments would still have resulted in significant organismic changes.)
Mars (and any other planet or moon potentially harboring life) has many microenvironments that may contain life; to conclusively prove that there is no indigenous life at all, anywhere on the planet, may be close to impossible, at least for the foreseeable future (and especially given our current ignorance—after all, we only know about one type of life). As long as the possibility of indigenous life cannot be excluded, populating Mars or any other planet with genetically modified organisms is out of the question.
If we encounter a habitable planet—and one which we know for sure is uninhabited—the question becomes harder to answer. We can come to that when the situation arises—which it won’t for a very long time.
Professor and Principle Investigator of the Ohio Musculoskeletal & Neurological Institute and Emeritus Professor of Space Biology at Nottingham University
Indeed we could. We have the capability to land robots on other planets. Currently we sterilize these to prevent accidentally contaminating other planets with microscopic life forms. If we wanted to not sterilize or deliberately send microscopic life to other planets, this is fairly easy to do. Similarly, labs on Earth routinely make and use genetically modified microscopic life forms. Thus, it is also fairly easy to send GMO microscopic life forms to other planets.
Whether we should is the more difficult question. Who benefits from doing this, and who loses out? Do the benefits outweigh the losses? If this is done to allow human habitation of another planet, then potentially all of humanity gains—whereas those aspects of planetary science that want/need to study a “natural” planet lose out. If this is done to allow for the commercial/financial gain of a few, does that outweigh the loss to science?
Assistant Professor of Astronomy and Molecular and Cellular Biology at the University of Arizona
It depends on the planet. An exoplanet around a star system is probably out of reach with current technology.
If the candidate planet is in our solar system, such as Mars…perhaps. It becomes a question of: For how much, or how long, are you willing to provide technological assistance to create a habitable volume elsewhere? The engineered organisms will most likely be severely restricted in the range of places they can inhabit. So far as we know, no amount of genetic engineering will enable terrestrial organisms to survive under freezing temperature and extreme soil oxidation conditions, such as those found in the Martian environment.
Subsurface ocean worlds such as Enceladus or Europa might work, but we haven’t precisely characterized their habitability, and it is difficult to foresee how the organisms would be delivered there if the shell of ice is kilometers thick.
That being said, genetically engineering organisms and evolving them under various conditions may allow us to understand the limits of life here on Earth.
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