Saturday, September 8, 2018

There will be no Hunter-Gatherers on Mars

Two headlines in summer 2018 caught the attention of space aficionados. Together they renew optimism on the part of some people that humans will become the first known multi-planetary species.

The first headline “A Large Body of Water on Mars Is Detected, Raising the Potential for Alien Life” appeared in the New York Times (July 25, 2018) and was based upon a paper published shortly thereafter in the journal Science (3 August 2018) providing radar evidence for subglacial liquid water on Mars.

The second headline “Beyond the Shadow of a Doubt, Water Ice Exists on the Moon” appeared in Scientific American (August 21, 2018). In that article the author, Leonard David, wrote that the water was “deposited in perpetually dark craters around the poles” and suggested that “the ice could be a boon for future crewed lunar outposts.”

These two headlines remind us that though we have yet to confirm the existence of life elsewhere in the universe—and perhaps that confirmation will never come—that living things require resources upon which to subsist. Thus, a search for the primary resources upon which life depends (or alternatively for the distinctive wastes generated by living entities)—both searches, we should mention, assume that we know what “life” is, exactly, which we don’t—often surrogate for the direct detection of alien organisms. Attempts to search for aliens organisms will follow any promising leads from the search for resources and waste.

Water being sovereign among the resource needs of life (most organisms will die of thirst long before dying of starvation), the discovery of extraterrestrial water thus points to putative indigenous life on those planets (and satellites) where it is detected. Whatever about the conjectured needs of alien life, without doubt humans are a thirsty species, and the existence of extra-terrestrial water encourages aspirations to support human life off this particular planet upon which you and I are discussing these issues.

Now, interesting though these developments may be, we might ask why an environmental scientist—an urban ecologist in particular—should be more than casually distracted by them? For two reasons, I think. Though it didn’t have to be so, the prospect of space colonization has often seemingly been motivated by concerns about resource shortages on Earth. Certain elements, such as deuterium used in nuclear reactors, are hyper-available on Mars and could be profitably returned to the ‘home planet’. Additionally, rare metals like platinum, gold, and silver, can be mined on Mars for use back on Earth.

Beyond these immediate implications, the two articles illuminate the following issues: the difficulty of defining (and detecting) life, the reaffirmation not only our sense of aloneness in the solar system, but also the herculean (and expensive) efforts that are expended in attempting to meet the neighbors, so as to speak, and finally the papers hint at the machinations that will be required to colonize another planet—maintaining life in xeno-environments.

Making space more tangibly part of the resource shadow of Earthlings is one thing but the prospect of space colonization as providing a alternative home in the event of planetary despoliation is quite another. Yet, there is in the literature of space colonization and terraforming a notion that off-planet colonies provide a “Plan B” in the event of a catastrophe on this planet.

Gerard K O’Neill (1927–1992) the Princeton physicist and space exploration enthusiast, framed his advocacy for space colonies explicitly in the context of concern over environmental pollution and the ‘evils” consequent from the Industrial Revolution. In The High Frontier: Human Colonies in Space (1976) O’Neill wrote “the evils of environmental damage (pollution and so forth) are minor compared to others that have appeared: sharp limits on food, energy and materials confront us at a time when most of the human race is still poor, and when much of it is on the edge of starvation.” The solution, as O’Neill saw it, was not to “retreat to a pastoral, machine-free society…” No, the future rather is in space colonies that should be free-floating in space and thus open to constant solar radiation supplying us with unlimited energy. Such space colonies, O’Neill wrote, will follow on as “an inevitable result of the large-scale development of space resources.” Space will ultimately become a “new Earthlike environmental range for humanity, bathed in continuous free energy…” — humans’ newest habitat.

I should note that in January 1976, O’Neill appeared before the Senate Subcommittee on Aerospace Technology and National Needs laying out a case for an Apollo-style program for building power plants in space. Ultimately, these plans were regarded as “nutty” and funding space colonization research was cut from NASA’s budget.


Space conquest has had a curious green tinge for decades. Colonizing space potentially extends the human project into its newest phase. For all its novelty, for all the ways in which space colonies capitalize upon emerging technologies, they nonetheless are an extension of the territorial expansionist impulse that has long been part of our species’ repertoire. Space colonies are besides—and this is really the main purpose of this short essay— the next increment in an explicitly urban project that began several thousands of years ago.

Although the term “colony” is used in the literature on expansion into space, many advocates preferring more neutral terms like “settlements” and “outposts.” Carl Sagan (1934 –1996), who remain the most famous space advocate referred to space “cities” rather than “colonies” to avoid the negative connotation associated with colonization. Sagan is being diplomatic— after all colonization has lost the luster of its heydays—but in calling them “cities” he is, at the same time, being terminologically accurate. 

In imagining the earliest cities, we can ask how their small populations were sustained. How did they transform their hinterlands? There is a significant literature that reports on such investigations. The sustenance of space cities and the degree to which they will transform other planets should interest us. Since this is to be our remote future and not our remote past, the future of the humanity may depend upon it

Conceiving of these space cities (or town, hamlets and so on) and embarking on space-urban-planning is a useful thought-experiment. It not only draws out a definition of what a city is—a question that has a long, contentious, and unresolved history— but also tasks us with creating a list of what we would need to bring along with us in order to sustain life off planet. For example, an astronaut tripping across the lunar surface did not need to bring gravity with them. However, strapped to their back and pumped into the lungs is a tank containing a rough approximation of the Earth’s atmosphere. That astronaut will also have access to other physiological and psychological necessities to endure the trip. What, on a grander scale, will an entire colonizing community need to pack with them to replicate, even minimally, the accoutrements of civilization?   


All colonized planets, and asteroids, and even space stations, will be urban in character.

There will be no hunter-gatherer phase on Mars, nor will humans need to reinvent agriculture there; we will load upon our space vessels our literacy, social hierarchies, capitalism, and all of the urban delights, excesses and disasters and take them along for the ride.

When or if cities are established on other planets the sequence of urban development will thus extend from Ancient/Classical cities (to around 1250), Mercantile/Colonial cities (to 175), Industrial/Imperial (to 1970), Post Industrial/Post-Colonial (to present), to Non-terrestrial/space cities. Since most of us live in post-industrial cities, we do not have direct access to other forms of urban development. Of course, there are remnants of previous stages accessible as either living fossils distributed across the landscapes of contemporary cities, or as ruins that we can visit or read about, but the more remote historical stages are obscure.

Image from Wikipedia